Holley Carb vs MY Edelbrock 750 [Archive] - Chevelle Tech

: Holley Carb vs MY Edelbrock 750


87caprice
Jun 21st, 11, 2:49 PM
Hey guys I have a Edelbrock 750 Electric choke on my engine and it runs great and all but this weekend I swapped a friends holley 750 on and it seems like the car picked up so much. My question is could you guys recommend a carb for my engine? This is also my daily driver but I also like to race it sometimes too since the local track here has opened back up. I'm not too worried about gas mileage but dont want to just throw away gas driving around town. I was looking at the Holley 670 and 770 SA and also the Holley 750. But want it electric choke. Thanks a bunch

350 bored .060 9.8:1 cr
4vr flattops
Ported/polished vortecs, 2.02/1.6 valves, milled 60cc, 3 angle VJ, bowl blend, etc
.028 head gasket
160 t-stat
weiand airstrike intake w/1" 4 hole spacer
750 eddy carb
Accel dizzy w/ accel 8mm red wires plugs gapped at .045 ACdelco
1.52 roller tip rockers
Lunati voodoo 60103 w/comp 941 springs
Headers straight through flowmaster 40s out the back with NEW X PIPE
TCI streetfighter 700r4
3000 stall 9.5" unit NEW Custom built.
8.5 rear, locker, 3.42 gears

427L88
Jun 21st, 11, 4:05 PM
The 750 vaccum secondary is avail with electric choke. Dont worry about it being "too big" its vacuum actuated. I personally dont see much merit in the "new" SA series of carbs, but imho....

This guy http://www.holley.com/0-80508S.asp

Shop around. Should find it for less than retail.

Not surpirising that the Holley ran better. the old Carter carbs were often junked in favor of a Holley ( in teh 70's) . the edels are old carter carbs. Nothing new.

mfret1970
Jun 21st, 11, 4:18 PM
Is your buddy's 750 a vacuum sec or a double pumper? I would think a 650 double pumper would be alot of fun on that motor, the double pumper "hits" harder than a vac sec.

marks412
Jun 21st, 11, 5:20 PM
Is your buddy's 750 a vacuum sec or a double pumper? I would think a 650 double pumper would be alot of fun on that motor, the double pumper "hits" harder than a vac sec.

I second the 650DP.

As far as the choke, does it get that cold in your part of the states?

bowtie0069
Jun 21st, 11, 6:11 PM
We spent hours screwing with jets/idle mixture/advance curve/timing,etc...trying to get a 3310 to idle both in neutral and drive on a mild 383. When we got it to work fairly well, I pulled out a Street H.P. 750 vac. sec. carb and bolted it on--perfect, out of the box.
The same engine with a 770 Street Avenger worked great also.
I was really impressed by the Street H.P. carb, but it's more money and has no choke. When we had my engine in a friend's Dodge Dart, we used the Street H.P. carb, and with a really tight converter and not enough gear, it ran 11.40's with just a jet change from out of the box.

87caprice
Jun 21st, 11, 6:49 PM
@427L88, thanks for the heads up. I've been looking around at the different holley carbs but have no idea of what I can put on my car to make it run a lot better than this Edelbrock.

@mfret and mark, Wow I never thought about a double pumper because I've always heard that they just dump tons of gas while crusing. The 750 carb that I used of his was a Holley carb but I dont know the name of it or model number of it. He just say it was a Holley and it was vac sec. As far as the weather here during the winter months, its not that cold here. Doest get below 20-30 degrees here. So its not really that cold. It may get to freezing maybe a few days out of the winter season but nothing as serious. Will the 650 or 750 DP be best and make the car quicker with than the Eddy 750. BTW, I have a Holley pressure regulator installed also.

jeff swisher
Jun 21st, 11, 7:29 PM
If you take the path of just slapping a carb on and hope it is better than what you got,,then you better research what your buddy loaned you..and find out what jetting his had....because it was probably closer to the optimum jetting for your ride than the jetting that is in the 750 edelbrock..

Have you played with jetting and springs and rods along with float levels in the 750 edelbrock?

I have for many years used the AFB style carbs and my racing buddy had a hang up about me running them,,,so one day i called him on it..he had a 750 double pumper with percys blocks and some other stuff..i let him put it on my ride and tune it to his hearts content...over 1/2 the day and he gave up..it would not pull as hard on the big end as my carter 750 afb...

He was to say the least,, confused.....I installed my 750 on his 400 poncho..and it was way snapier and pulled harder.....
These were old style holleys and carter carbs..his was bought in late 80's my afb was 1990....better carbs out now ,,,but none will work to the fullest with the wrong jetting and air bleeds..etc etc

Geo71
Jun 21st, 11, 7:31 PM
Have you ever done anything to the Edelbrock carb or is it stock out of the box?

1966_L78
Jun 21st, 11, 8:02 PM
If you take the path of just slapping a carb on and hope it is better than what you got,,then you better research what your buddy loaned you..and find out what jetting his had....because it was probably closer to the optimum jetting for your ride than the jetting that is in the 750 edelbrock..

Have you played with jetting and springs and rods along with float levels in the 750 edelbrock?

I have for many years used the AFB style carbs and my racing buddy had a hang up about me running them,,,so one day i called him on it..he had a 750 double pumper with percys blocks and some other stuff..i let him put it on my ride and tune it to his hearts content...over 1/2 the day and he gave up..it would not pull as hard on the big end as my carter 750 afb...

He was to say the least, confused.....I installed my 750 on his 400 poncho..and it was way snapier and pulled harder.....
These were old style holleys and carter carbs..his was bought in late 80's my afb was 1990....better carbs out now ,,,but none will work to the fullest with the wrong jetting and air bleeds..etc etc

I agree... Just because its a Holley doesn't mean it will run quicker... The Holley is a better design for racing, as there are more aspects to fine-tune. A DP is great for no-compromises, WOT performance, but is far from the most fuel-efficient carb, which can be a consideration on a street car...

I have actually swapped several DPs for VS Holleys, and often ran better (quicker ETs at the track) with the VS. These were tuned (jets, cams/squiters, VS springs). While the DP's felt like they hit harder, the ETs didn't show much of anything... And on the street, the DPs were harder to keep traction without detuning further...

Slicks or drag radials and a good suspension, DP will offerthe best performance, but then its also a compromise with street driven (often more fuel than needed when cruising around).


The past 15 years, I got into Edelbrocks more and more. I am far from an expert tuner on them, but they have performed very well... On every car (at least 5), they have improved ETs over the previous Holleys (partially because some Holleys were DPs that were hard to get traction-street cars)... granted, these were all traction limited street cars (high 13s to mid 14s).

My current ride uses an Edelbrock. Despite the "wimpy" Edelbrock, it still easily overpowers the drag radials on the street (from a 20-25 MPH roll). The Edelbrock has been dead reliable. Out-of-the-box, I have gone 12.34s at 110 with a 1.71 60 ft time, with a lowered, road-race/pro-touring suspension. Ihad to leave near idle (about 1500 max) or the tires would smoke and 60-ft droppped to 1.9-2.1... I still haven't had a chance to run it after some tuning.

I had it on for 3+ years, and never a problem. I had an ignition problem a few weeks ago, that I thought was carb-related. "cleaned/rebuilt" the carb, and it fired and ran nearly perfect before I even rechecked the tune...

Personally, I wouldn't spend money on a new carb, unless you have tried tuning and reached the limits (or simply "need" a new carb).


It would be very interestign to know IF you ever tuned the Edelbrock (properly), and what ETs it runs... and them some ETs with a Holley.

It seems most people that bash the Edelbrocks, have never tried tuning/racing them (and maybe never even ran one)...

87caprice
Jun 21st, 11, 8:04 PM
Jeff and George, first off Hi guys and thanks for the responses. But I've had this carb for a year or more and I've never had it rejetted or anything like that. Its still OUT OF THE BOX adjusted except for the 2 screws on the front of it. Honestly where I'm at, I dont know many places that has the KNOWLEDGE to even do that CORRECTLY. The ONE guy that I do feel comfortable with jetting it is always telling me to take it off and put a smaller one on. He's always showing this Holley cfm booklet when determining a carb for an engine. But he say he would not adjust my carb because its too big for my engine. Thats why I was asking here on what I should do. I tested my car out with that Holley and it felt 10x better running through the 1/4 than my eddy 750 has ever felt. But Im at the point now where I want my car tuned RIGHT and I just want to make sure I have the CORRECT carb for my application. If its any other information you guys need please ask. You all have guided me this far and I just wanna be a tad bit quicker come Independence Day. And Im going to call him in a few mins to ask him what all he's had done to his carb. Thanks

87caprice
Jun 21st, 11, 8:13 PM
Tony, No I've never got it adjusted correctly or anything. I've been reading on here and the internet about an adjustment kit for the Edelbrock carb that I'm thinking of ordering within the next few days and maybe just drop my car off at a SpeedShop. But I want to make sure Im ordering the correct kit. I really want it to perform better than what it is because I know it can but I do not know how to adjust them myself and I just hate taking my car to a shop for anything. But it seems like this is what Im going to have to do. Right now I would like for it to be a LOT quicker than what it is and the gas mileage thing im not too worried about but dont want to just WASTE it you know. I do have a 92 5spd Honda Accord so for extra long trips thats what she is for. lol. The longest 1 way trip I put my car in is maybe 200 or so miles so I dont think gas mileage would be that bad on the interstate. I dont drive it around town much. I just need it to perform like it should now.

dirtlips408
Jun 21st, 11, 8:29 PM
Check these quickfuels out....

680 vac sec with electric choke or 735 vac sec with electric choke.

http://www.quickfueltechnology.com/carburetors-ss-series/vacuum-secondary-1.html

Geo71
Jun 21st, 11, 10:19 PM
Jeff and George, first off Hi guys and thanks for the responses. But I've had this carb for a year or more and I've never had it rejetted or anything like that. Its still OUT OF THE BOX adjusted except for the 2 screws on the front of it. Honestly where I'm at, I dont know many places that has the KNOWLEDGE to even do that CORRECTLY. The ONE guy that I do feel comfortable with jetting it is always telling me to take it off and put a smaller one on. He's always showing this Holley cfm booklet when determining a carb for an engine. But he say he would not adjust my carb because its too big for my engine. Thats why I was asking here on what I should do. I tested my car out with that Holley and it felt 10x better running through the 1/4 than my eddy 750 has ever felt. But Im at the point now where I want my car tuned RIGHT and I just want to make sure I have the CORRECT carb for my application. If its any other information you guys need please ask. You all have guided me this far and I just wanna be a tad bit quicker come Independence Day. And Im going to call him in a few mins to ask him what all he's had done to his carb. ThanksI'd try alittle tuning with your existing carb first. Since you haven't, might as well. Figure out what model # you have then look on the Edelbrock website it will give you the model # for the tuning kit.

These carbs are very easy to tune once you get the hang of it. If you have the manual for it, there is a section on tuning it. Changing the front jets/rods and springs are super easy. The rear jets are alittle harder since you have to take the top of the carb off. There is some linkage to take off, but once you see what to do, its really easy. On the Edelbrock websire are a bunch of tech videos that are really helpful too.

If I can tune these anyone should be able to. :) I'm thinking the Holley was probably jetted abit bigger is what the difference was....not just that its a Holley.

Winston Wolf
Jun 21st, 11, 10:29 PM
I changed from a properly jetted Edelbrock AVS 800 atop a standard Performer RPM manifold to a Prosystems Holley 950 HP on a ported RPM Airgap with a 1" spacer. I also changed to a 1.6 rocker on my intake at that time. I picked up a whopping 16 RWHP, most of which I attribute to the rocker and intake swap. Bottom line is, don't expect miracles when changing to a Holley.

Before I bought a new carb, I would buy a rod/jet kit for the Edelbrock and tune it properly. Under 500 HP the Edelbrock will run right with a Holley if set up correctly. Read the tuning manual, and take each circuit one at a time. Tune the idle with a vacuum gauge, (if you can turn a screw and read numbers on a gauge, you can do it correctly) then work on the WOT, then the cruise and transitions.

and fwiw, I can change Edelbrock rods and springs in less than a minute, and I know I can change all 4 jets in that edelbrock faster than my double pumper, all without having to take my fuel lines all apart and spilling gas everywhere. I hate the process on a Holley.

87caprice
Jun 21st, 11, 11:49 PM
Well I really appreciate the help, I will order a calibration kit in the morning and I will go after the job myself. I'm mechanically inclined so I shouldn't have a problem since the manuals are pretty straight forward. I've noticed there are 2 750 carbs, the kit for my model number #1411 is kit #1489. But I have a question as to why the carb #1407 has a different kit #1480. I know my carb is jetted lean out the box and the 1407 is jetted richer but why 2 different kits? Should I get the recommended kit or would u prefer the kit for the 1407?

jeff swisher
Jun 22nd, 11, 12:17 AM
I have always swapped the front jets to the rear and the rear to the front. on the edelbrock afb style carbs,,for a quick and cheap way to find out if it is really jetted lean or not....most i have found to be too rich .. and the swap makes a big difference.

About a carb being too big,,HOG WASH..There is a limit to too big but not a 750 on a 350 chevy..You just need to get the jetting correct..

We ran tweaked 850's on 427 drag race 4 speed cars and when swaping to the 1150 dominator we went .3 quicker... less wheel stand than the 850..but you start rollin the bigger carbs always pulled harder..correct jetting is key..

If i need more than 850 i go with 2 carbs now..We run a 355 with ported 305 heads and 2 600 edelbrocks and a 292 comp cam..this car runs well with 275 or 456 gears...pulls hard from right off idle to 7500rpm...

Lots of atomization and speed through the runners on that deal..the 292 is 244 at .050 it clicks off 11.94's in a 78 nova on 91 octane..daily driver car....Everyone who sees the 2 600 edelbrocks tells us to go holley or that we are over carbed...untill they see it run and find out the heads are 194 150 valved 305ho heads...and the converter only stalls to around 2200..then they tell us that thing is dialed in pretty well..i think there is some 11.60's in it with a good converter..but the cheap B&M will stay for now

sorry got a little windy..i just like them big cfm's:D

Geo71
Jun 22nd, 11, 1:15 AM
Well I really appreciate the help, I will order a calibration kit in the morning and I will go after the job myself. I'm mechanically inclined so I shouldn't have a problem since the manuals are pretty straight forward. I've noticed there are 2 750 carbs, the kit for my model number #1411 is kit #1489. But I have a question as to why the carb #1407 has a different kit #1480. I know my carb is jetted lean out the box and the 1407 is jetted richer but why 2 different kits? Should I get the recommended kit or would u prefer the kit for the 1407?Get the recommended kit for your carb and start there. It will have the rods and jets for calibrating the carb closest to what you have....you may end up needing to buy another set of jets or rods, but they arent too bad to buy.

Winston and Jeff have been a great help for me with tuning mine.

Winston Wolf
Jun 22nd, 11, 1:29 AM
Well I really appreciate the help, I will order a calibration kit in the morning and I will go after the job myself. I'm mechanically inclined so I shouldn't have a problem since the manuals are pretty straight forward. I've noticed there are 2 750 carbs, the kit for my model number #1411 is kit #1489. But I have a question as to why the carb #1407 has a different kit #1480. I know my carb is jetted lean out the box and the 1407 is jetted richer but why 2 different kits? Should I get the recommended kit or would u prefer the kit for the 1407?


1407 Comes with: Metering Jets - Primary .113, Secondary .107; Metering Rods - .071 x .047; Step-Up Spring - orange (5" Hg).

1411 Comes with: Metering Jets - Primary .110, Secondary .107; Metering Rods - .075 x .047; Step-Up Spring - orange (5" Hg).

Here is what comes in each kit:

(Calibration Kit for #1407, #1410, #1412 and #1413)..........Part# 1480 http://www.edelbrock.com/images/buyitnow.gif (http://store.edelbrock.com/1480calibrationkitfor140714101412and1413performerc arbs.aspx)
.065 x .037 .101
.065 x .047 .104
.068 x .047 .107
.073 x .047 .110
.073 x .052 .113
N/A. 116

(Calibration Kit for #1411)..........Part# 1489 http://www.edelbrock.com/images/buyitnow.gif (http://store.edelbrock.com/1489calibrationkitfor1411performercarbs.aspx)
.070 x .042 .104
.073 x .037 .107
.073 x .042 .110
.075 x .037 .113

Looks like the 1411 kit has rods that are leaner in the cruise portion.

I would probably get the 1407 kit, (it will give you more combos) and buy the rods from the 1411 kit if you're worried about it. (I wouldn't to start) You can pull the tuning charts from the instructions and see what combos you can come up with with each kit. One suggestion would be to get the 1407 kit and start with the 113 main jet and a 73 x 47 rod. That should be a point on the chart and use that as your baseline.

MEJ1990TM
Jun 22nd, 11, 2:00 AM
I can't explain why, but I have never really favored Edelbrock/Q-Jet style carbs. I just find the Holley carbs so much easier to work on. I'm sure the Edelbrock will run every bit as good as a Holley when it's tuned up though.

For what it's worth I got the 3310 that is in he '70 to run pretty well. It's jetted a bit fat so the gas mileage has gone down a little bit. No signs of running rich though. Plugs come out clean as a whistle.

jeff swisher
Jun 22nd, 11, 2:16 AM
I have made specific rods for some of my carbs,,takes a long time sanding but you can remove .001" at a time,,and you can create a gradual taper into the power mode...then there is the secondary air valve opening..

you can grind some weight off of it and make it open sooner or you can add weight and make it delay the opening..although stock is hard to beat on most aplications once the jetting is set up...

On our dual 4 nova with the 600 carbs i run the orange spring and another spring in there with the orange one..I took the other spring out of an INK PEN...makes the power mode come in really quick and really improves the snappieness of the throttle...the engine pulls 11.5" of vacuum at 1000 rpm
idle is set at 1100...Timing plays a huge roll I usually have 20-22 initial and whatever total she likes for the weather..usually 38-41 total

I have used the ink pen spring trick since the 80's...as long as the power piston stays down at idle you are good...a must try to all who run these carbs

658Chevy
Jun 22nd, 11, 2:35 AM
I have the Edelbrock 650 AVS, which has the added tuning of the primary to secondary transition. I had it dialed in perfect, and then changed the distributor weight springs from one light/one medium, to two medium. After that there was a slight flat spot when transitioning from primaries to secondaries. It took me about60 seconds to adjust the AVS screw, and now it runs perfectly again. Very happy with this carb. Put it on four years ago with almost no maintenance since.

1966malibu
Jun 22nd, 11, 2:38 AM
I have made specific rods for some of my carbs,,takes a long time sanding but you can remove .001" at a time,,and you can create a gradual taper into the power mode...then there is the secondary air valve opening..

you can grind some weight off of it and make it open sooner or you can add weight and make it delay the opening..although stock is hard to beat on most aplications once the jetting is set up...

On our dual 4 nova with the 600 carbs i run the orange spring and another spring in there with the orange one..I took the other spring out of an INK PEN...makes the power mode come in really quick and really improves the snappieness of the throttle...the engine pulls 11.5" of vacuum at 1000 rpm
idle is set at 1100...Timing plays a huge roll I usually have 20-22 initial and whatever total she likes for the weather..usually 38-41 total

I have used the ink pen spring trick since the 80's...as long as the power piston stays down at idle you are good...a must try to all who run these carbs

Jeff your giving away all the secrets :D

Brandon along with the strip kit you are getting this would be a very well spent $20.00
http://www.summitracing.com/parts/SAD-SA130/
Read everything you can and come back here and ask lots of questions.

jeff swisher
Jun 22nd, 11, 7:49 AM
1966malibu wrote:Jeff your giving away all the secrets :D

Not all of them ,,and most people aren't that enthusiastic.

And the avs is an excellent carb..and do not forget the dreaded thermoquad,,,very tuneable,,if there was ever a red headed stepchild of carbs i would say thermoquad or the variable-venturi for the 2V variety

87caprice
Jun 22nd, 11, 11:04 AM
Wow guys you are all so very helpful. Im in the process right now of ordering the 1407 kit and also ordering the Edelbrock tuning book. I love to read so maybe I can learn enough to maybe help some guys here in my small hometown that are having Edelbrock troubles. I really really appreciate all of you guys for the help and hope you all be here when I start tuning it when the supplies make it. Again thanks a ton and if there are other Eddy secrets you all have please let me know.

I also have another question concerning the 750 eddys... I've been reading that the secondarys dont open up as much on there because of a linkage on the passenger side that most have been grinding a little bit off. Have any of you heard about this issue with the 750s?

Buzzbomb
Jun 22nd, 11, 12:54 PM
Assuming a 1411 with the stock specs posted above and a tight budget...

To richen up your carb about 5% on both primary and cruise, you could keep your 110 jet in the front and simply get a set of 73X42 metering rods. Of course, going from a 107 to a 110 jet in the rear would richen up your secondaries about 3%. If you go to a 113 jet in the rear, you are richening it up 5%.

If it were me, I'd keep it within 5% RICHER or LEANER, probably richer in your case since you stated the 1411 comes "lean". Anymore and you would probably be sacrificing too much mileage, IMHO. This means simply keeping your original primary jets, getting a set of 73X42 primary rods, and jetting the secondary to 113 jets.

Since you DID mention mileage, forget the 650 Double Pumper. A vacuum secondary carb is nearly always a better choice for a heavy street car (87 Caprice?) with an automatic trans.

87caprice
Jun 22nd, 11, 1:20 PM
Yes sir, well as of right now im not really on a budget thanks to BETONUSA.com during the NBA Finals. Rent/bills paid up for the year so now its play time for a lil bit. SSHHHH dont tell my girlfriend though. Anyways, I've ordered the Edelbrock Tuning Booklet that was recommended and the calibration kit #1480 for the Eddy 750 carb #1407 to use in my 750 #1411. So hopefully that stuff will be here by Friday or Saturday from Summit and I can have Sat or Sun to play with some tuning after I finish reading. And yes mileage is not really an issue but is an issue if that makes sense but I want the most performance out of my carb. Maybe I can tune it where its super good on gas during when I want to just travel and once I get to my destination and want to play a little bit just change out the jets since I hear it takes less than a minute to swap out. But seriously Im taking in all you guys are tellin me to heart so its just a matter of a couple days when my order makes it here and I can inform you guys of whats going on.

BowtieAaron
Jun 22nd, 11, 1:22 PM
I went from a well dialed in 3310 750 vac sec to an old 4777 Holley 650 hp and picked up 3 mph on a crappy night.

I then changed intake gaskets and added another carb spacer and picked up 7 mph to trap 112.

I put a decent running no tuned 750 with choke horn milled on and lost 2mph.

I am in the mix of putting another 4778 on the car and trying to tune now.

I also had an edelbrock on my 406 in my s10, I swapped to the well tuned for my 350 3310 and it was night and day, I then swapped to the 1st 4777 650dp and the truck flat out ran, I didn't touch anything! But I sold the truck so I don't know if it picked up any power.

I would run a 650dp on your 350. The throttle response from the 650 vrs the 2 750's I ran on the street is amazing. Makes the car more fun!

1966_L78
Jun 22nd, 11, 1:39 PM
Maybe I can tune it where its super good on gas during when I want to just travel and once I get to my destination and want to play a little bit just change out the jets since I hear it takes less than a minute to swap out.

I do this every year. Its the primary metering rods that are VERY easy to change... I live at about 300 ft elevation, and every year I go to a multi-day car show in the mountains (4500 ft and I need to go over 7000 ft passes in the mountains), so I swap metering rods to a leaner cruise. It really does help keep the plugs cleaner, and its about a minute to change, including removing the air cleaner...

Buzzbomb
Jun 22nd, 11, 1:59 PM
If you calibrate your carb with your 110 jet and the 73X47 rod in your kit, you are about 5% richer on the primary and no richer on the cruise assuming the info for a stock 1411. Since cruise is not an issue, I would try this first. This ONLY richens the power circuit. I can guarantee the rounded percentage numbers I am giving you are 99.9% accurate. This can be accomplished with a metering rod ONLY change which is easy on an Edelbrock carb. If changing ONLY the rod works for you, THEN take the top off, and put the 113 jet from the kit in the secondaries. You'll then be about 5% richer on the POWER jetting, and 6% richer on the SECONDARY jetting, and NO richer on cruise. You haven't posted idle vacuum, so I can't say anything about the step up springs. In a nutshell, makes changes in SMALL increments.

Going to a 113 jet, 73X47 rod will make you 15% richer on the primary and 6% richer on cruise. IMHO, you should go from your STOCK calibration and determine percentages richer or leaner from that. I'm from the Holley school of tuning and I do it with my Qjet- 5% at a time to see what works. 5% more or less works out to a jet change or two in a non-metering rod style carb.

Winston Wolf
Jun 22nd, 11, 2:27 PM
If you calibrate your carb with your 110 jet and the 73X47 rod in your kit, you are about 5% richer on the primary and no richer on the cruise assuming the info for a stock 1411. Since cruise is not an issue, I would try this first. This ONLY richens the power circuit. I can guarantee the rounded percentage numbers I am giving you are 99.9% accurate. This can be accomplished with a metering rod ONLY change which is easy on an Edelbrock carb. If changing ONLY the rod works for you, THEN take the top off, and put the 113 jet from the kit in the secondaries. You'll then be about 5% richer on the POWER jetting, and 6% richer on the SECONDARY jetting, and NO richer on cruise. You haven't posted idle vacuum, so I can't say anything about the step up springs. In a nutshell, makes changes in SMALL increments.

Going to a 113 jet, 73X47 rod will make you 15% richer on the primary and 6% richer on cruise. IMHO, you should go from your STOCK calibration and determine percentages richer or leaner from that. I'm from the Holley school of tuning and I do it with my Qjet- 5% at a time to see what works. 5% more or less works out to a jet change or two in a non-metering rod style carb.

I don't disagree with any of this, but I would still pull the top off first. Set the floats to make sure they are correct. That will eliminate one tunning step and should alway be done with these carbs as a first step, the factory can't seem to do it before they send them out.

87caprice
Jun 22nd, 11, 3:37 PM
I really dont know how to thank all you guys but I'm definitely taking in everything that you are all saying. But as of right now I can't play with any jetting because the kit isnt here yet, lol. But I've adding this thread to my favorites in my phone and on the pc so when they do make it hopefully this weekend or Friday I will try everything you guys are telling me. I just thought, hopefully the kit and book be here Friday so that I can test Friday evening and Saturday morning because Sat noon I have to go out of town for a RUN FOR AUTISM. Its like a 3.5 mile run to support kids with autism so Saturday afternoon and evening is out of the question. DARN........I was reading you said that I need to check the floats in the carb. Is this something that I can do before the jets come in or should I wait til they make it here?

Buzzbomb
Jun 22nd, 11, 3:44 PM
I don't disagree with any of this, but I would still pull the top off first. Set the floats to make sure they are correct. That will eliminate one tunning step and should alway be done with these carbs as a first step, the factory can't seem to do it before they send them out.

If that's the case with new Eddy carbs, DO THE ABOVE FIRST. The float level HAS to be right to get all the rest right. Otherwise, nothing is being accomplished via tuning.

I've always run used stuff, so I sometimes assume that people tear it all apart and do those things before installing, which is a snafu on my part :) .

IF you take the top off to check the float levels, go ahead and put the 113 jets from the kit in the secondary. As I stated, this will richen your secondaries by 6%. In all likelihood, this will be a change that is worth doing. You can then start tuning from the baseline of your stock calibration on the PRIMARY side. As I stated before, if this were my carb, I'd leave the PRIMARY jets alone and try a rod change first. The reason why Qjets and Edelbrocks use metering rods is to have BOTH power and mileage. The nice thing about the Eddy rods is that you can tune the power without touching the cruise provided the jet stays the same. I would assume the "trick kits" for Edelbrock come with a few air horn gaskets. Just don't overtorque the screws.

Winston Wolf
Jun 22nd, 11, 7:51 PM
If that's the case with new Eddy carbs, DO THE ABOVE FIRST. The float level HAS to be right to get all the rest right. Otherwise, nothing is being accomplished via tuning.

I've always run used stuff, so I sometimes assume that people tear it all apart and do those things before installing, which is a snafu on my part :) .

IF you take the top off to check the float levels, go ahead and put the 113 jets from the kit in the secondary. As I stated, this will richen your secondaries by 6%. In all likelihood, this will be a change that is worth doing. You can then start tuning from the baseline of your stock calibration on the PRIMARY side. As I stated before, if this were my carb, I'd leave the PRIMARY jets alone and try a rod change first. The reason why Qjets and Edelbrocks use metering rods is to have BOTH power and mileage. The nice thing about the Eddy rods is that you can tune the power without touching the cruise provided the jet stays the same. I would assume the "trick kits" for Edelbrock come with a few air horn gaskets. Just don't overtorque the screws.

Are you sure you didn't mean put the 113 in the primaries? The stock calibration for the secondaries is a 101 jet. We don't even know if he is lean or rich. That would be almost a 10% richening of the secondary orifice. (from stock .101 to .113)

Buzzbomb
Jun 22nd, 11, 10:50 PM
1407 Comes with: Metering Jets - Primary .113, Secondary .107; Metering Rods - .071 x .047; Step-Up Spring - orange (5" Hg).

1411 Comes with: Metering Jets - Primary .110, Secondary .107; Metering Rods - .075 x .047; Step-Up Spring - orange (5" Hg).


Keep those air horn gaskets handy :D

I think you were right the first time..According to the online manual, the 1411 comes with a .107 stock secondary jet, so I stick by telling him to go to a 113 for a 6% richer mix on teh secondaries. As above, he could even try a 110 for a hair richer at 3%. I like richening up the primary power and secondaries over doing anything with a cruise tip change if that doesn't require any attention. I still think he should try a rod change in the primaries first to leave the cruise mix alone. This can be accomplished with the 73X47 rod in the kit and his current 110 jet. If he puts in a 113 in the primaries and keeps his stock rod, he's 10% richer on power and 6% richer on cruise, and the 73X47 rod with a 113 jet gives him nearly 15% richer on power and the same 6% on cruise, which is too rich if his car is running pretty good now but a little down on power, IMHO..

Winston Wolf
Jun 23rd, 11, 12:32 AM
All these rod and jet numbers were getting me confused. Go with what he said.

One thing you might want to consider, with 1-2 hours max on a chassis dyno, you can figure out everything the car needs. Might be the best 100-200 bucks you spend. I have a wideband, so I never have to guess or do much plug reading and it makes tuning much safer, faster, and more accurate.

One observation I did have is that the % of change in the book does not correspond with the % of change to your actual a/f ratio. It took big jumps to see any measureable results on the meter when tuning the cruise portion.

If I had to tune one on a car today, I would do the idle circuit first, then dyno it for the WOT and secondary jetting, and then lastly work on the cruise portion of the rod, leaning out the cruise until I had issues, then go back up rich until it worked well or I had an a/f ratio I was shooting for.

Of course if you can find a Mustang Dyno or a Dynojet with and eddy current, you can do it all in one shot real easy....

87caprice
Jun 23rd, 11, 3:06 PM
Guys that would be great if I could get on a dyno but there isnt a dyno that I know of in the surrounding areas. I really wouldn't want to drive the car 2-3 hours just to get on a dyno......I just purchase a vacuum gauge from Oreillys during my lunch break so I would have that handy this weekend when the shipment comes in. My car doesnt have any O2 sensors or anything on it so a wideband can't be used correct? Should I get some of them installed in my headers or would the vacuum gauge be good enough for the carb adjustments?

Buzzbomb
Jun 23rd, 11, 4:07 PM
Guys that would be great if I could get on a dyno but there isnt a dyno that I know of in the surrounding areas. I really wouldn't want to drive the car 2-3 hours just to get on a dyno......I just purchase a vacuum gauge from Oreillys during my lunch break so I would have that handy this weekend when the shipment comes in. My car doesnt have any O2 sensors or anything on it so a wideband can't be used correct? Should I get some of them installed in my headers or would the vacuum gauge be good enough for the carb adjustments?

You can successfully tune your car with a vacuum gauge, timing light (how's your timing? total timing known? Timing FIRST then carb) and a stopwatch or maybe some runs at the strip. Will it be exact to the nth degree as it would be with some sort of exhaust reader or something similar? No. Will you notice the difference? Hard to say. If you make small changes first, inform yourself about what exactly it is you're doing and why you are doing it, and start tuning with TIMING FIRST using your engine as the testbed, probably not a whole lot..I saw timing mentioned earlier in this thread, but not by you. That's why I'm mentioning its importance.

That being said, if you have the cash and a dyno available that is well regarded, it is probably worth the money. I've never done it, so I can't say one way or the other. HOwever, you CAN tune it well on your own with the proper tools, knowledge, and last but not least, patience. Tuning takes time with a lot of trial and error thrown in.

87caprice
Jun 23rd, 11, 5:26 PM
I have the cash for a hour or two to take it to a dyno but gosh the closest one to me that I know of is in Baton Rouge which is roughly 3hrs away. Thats a nice little drive for just a dyno. But I might consider soon.

My timing I have set at 16* then 34*, sorry I didnt mention it earlier. yes I have a stop watch that I run with in the evenings after work that I can use and the vacuum gauge (new). Is there anything else that I would need besides what's listed above. If not, after reading the book and trying different jets like you guys suggested I will go after it hopefully 2mar evening if not Sat evening after Autism run.

jeff swisher
Jun 23rd, 11, 9:01 PM
#1 we know that your butt-O-meter is working.
how do we know?,,you installed another carb and felt the power difference..
I can always feel the power difference when i change timing or jets..and all i need is the US highway system and my first 2 gears..to get a great tune

Possibly an on ramp....I will floor it run it through 1st and feel how she pulls as i am watching how fast the tach needle is climbing..then at the sweet spot i grab second...i feel how well she recovers and run it up in the rpm range,,a lot can be felt in second...change timing and do it again..change jets and do it again and again untill you feel that there is no more left in it.....then play with cruise...you can fatten the rod in the cruise mode untill a steady cruise speed results in bucking or rough feeling...then "thin the rod" untill it is gone....perfect

I like to pull over on the shoulder on the highway..then do the accellerate test...of course out of the city limits..

87caprice
Jun 25th, 11, 11:41 AM
Well guys I just checked the vacuum this morning before I left for the run. The run has just ended and this is my reading for the vacuum at idle AFTER I adjusted the idle mixture screws. Its fluctuates between 14-15 Hg and sometimes up to 13. But I've read that could be due to the cam is why it wont stay steady.

When I first hooked the gauge up BEFORE touching the idle mixture screws it was all over the place. A guy played with my mixture screws and had them wwaaayyyy out and gas smelling all over and that reading was between 9-15 moving very fast.

I've been reading my book you guys wanted me to order and it was very helpful in understanding the Edelbrock carbs. And I've also looked at everything in my Edelbrock #1408 tuning kit and I see the .073x.047 you also recommended me to install first. But before I do that, I am going to the part store to buy a pack of the air horn gaskets and make sure/adjust the floats to the recommended 7/16 distance from gasket. BTW, dont know if this matters or not but I have my regulator set at 4.5 psi, is that too low or should I bring it up higher. Its a Holley regulator that goes from 4.5-9psi if im correct.

Thanks

Bob West
Jun 25th, 11, 11:52 AM
650 dp would be my choice! :yes: I don't see too many Edelbrock AFB's in the pro stock ranks, they have the ability to test anything and you just don't see those shiny Edelbrocks sitting on those tunnel rams ;) Maybe they're like fuel injection or the SV 1, just not approved by the NHRA yet, LOL.

1966malibu
Jun 25th, 11, 12:02 PM
Brandon Eddie's are very sensitive to fuel pressure. You should run no more than 6psi and no less than 2 psi at WOT. Edelbrock suggest 5.5 psi is best.

trroscoe
Jun 25th, 11, 6:56 PM
To make an Edelbrock perform better on a performance application here is what you do

Edelbrock says to set the floats 7/16" away from the top/gasket. I eyeball it half of this,yes the float level is higher but it makes it to where your mixture screws should not be out more than 1 turn and allows the main circuit to come in quicker under acceleration


Do some searching and you will find this information. If you set the floats the way Edelbrock says to they will be too low. Set them to half of the measurment they tell you to and the carb will work much better. I don't eyeball them though I use a smaller drill bit.

This got rid of any flat spots I had on going from idle to WOT and allowed me to have better adjustment on my mixture needles. Try it it works.

jeff swisher
Jun 26th, 11, 12:37 AM
Well i will admit that what i have found when trying to use the edelbrock AFB carbs under max 1/4 mile drag car deal is when idle vacuum gets down to 4inches or 5 inches and is fluctuating it is almost impossible to make the power piston stay down in the idle cruise mode...so you will have a really messed up primary circuit constantly changing as the power piston bounces up and down...even the lightest spring does not cut the mustard here....you will be lucky if the plugs aint fouled by the time you make it to the starting line..

That is the only problem i have seen that i could not correct.,,so yes holley wins there

87caprice
Jun 29th, 11, 11:07 AM
Ok guys today is the day that the air horn gaskets from Jegs comes in so I can finally take the top of the carb apart. I've changed the metering rods to the .073x.047 that was suggested and its feels like it moves more easily now. That was the only change to it that I've done besides adjusting the idle mixture screws also. So today when I get home from work and FedEx has dropped off my A.H. gaskets I'm going to adjust the floats and start over again and while Im in there Im also going to change the secondary jets to the .113 as suggested. The cars feels much better/smoother now with that SMALL change so Im hoping I can make it even better with more adjustment. I've read that you can set the floats to a half of 7/16" to about somewhere along the lines of 1/4" and it would make the "main circuit" come in quicker. I've set my fuel pressure to 5.5 psi. I took it thru 1st to 2nd and I think what Im feeling is that my secondarys arent opening up as quick as they were on that Holley. I was reading my book and it said that I can bend the rod on that side to make them open up quicker/earlier or grind off some weight. But dont know how much I would need to grind!!!! The Holley carb that we put on, my bud said that it was a "street HP mech secondary carb".

greg_moreira
Jun 29th, 11, 11:17 AM
Sounds like your moving in the right direction. As far as your earlier question about fuel pressure....I didnt see if there was a response but adjust your regulator to the max amount that edelbrock reccomends.

If they reccomend 5.5 PSI as mentioned earlier....definitely set your regulator there. That way there is less of a chance that any issue/lack of performance is related to inadequate fuel delivery.

The Edelbrock carbs arent exactly ones that Im super familiar with, but regaurdless any out of the box carb can be made to run better with a little work.

Its not a guarantee that everything you try will make it run better right away, but sooner or later you will find a good tune with some experimenting.

Geo71
Jun 29th, 11, 11:20 AM
Ok guys today is the day that the air horn gaskets from Jegs comes in so I can finally take the top of the carb apart. I've changed the metering rods to the .073x.047 that was suggested and its feels like it moves more easily now. That was the only change to it that I've done besides adjusting the idle mixture screws also. So today when I get home from work and FedEx has dropped off my A.H. gaskets I'm going to adjust the floats and start over again and while Im in there Im also going to change the secondary jets to the .113 as suggested. The cars feels much better/smoother now with that SMALL change so Im hoping I can make it even better with more adjustment. I've read that you can set the floats to a half of 7/16" to about somewhere along the lines of 1/4" and it would make the "main circuit" come in quicker. I've set my fuel pressure to 5.5 psi. I took it thru 1st to 2nd and I think what Im feeling is that my secondarys arent opening up as quick as they were on that Holley. I was reading my book and it said that I can bend the rod on that side to make them open up quicker/earlier or grind off some weight. But dont know how much I would need to grind!!!! The Holley carb that we put on, my bud said that it was a "street HP mech secondary carb".I'd wait till you change the rear jets and see what that does. Then look at the linkage. I went from (600cfm) 95 rear jets up to 101 and it made a large difference. Going to try 104 and see if I gain any more.

87caprice
Jun 29th, 11, 11:50 AM
@Greg......Yes at first I had my fuel pressure set at 4.5 because I wasnt trying to race it at all and it was only driven on the interstate and to Anytime Fitness or grocery store. But now since all of my friends are coming to my hometown for the 4th they are bringing their old schools and we all are going to the track here in Monroe Fri and Sat. So hopefully I can continue to hush them up a little bit. But now I've set it up to 5.5 like Eddy recommends and Im going to leave it there. And im in the process of learning these carbs so I going to test and test unitl Im happy with it.

@George....Wow thats cool man. I'm going to wait until this evening about 5-6 pm CT to play with it again. Im not worried about the power during regular driving or anything my main concern is 1/4 performance. Anything else Im just not concerned with at the moment, LOL. I see you went up (6) on your rear jets, which control your secondarys correct, did it perform at lot better as far as POWER is concerned??

427L88
Jun 29th, 11, 12:21 PM
And the avs is an excellent carb..and do not forget the dreaded thermoquad,,,very tuneable,,if there was ever a red headed stepchild of carbs i would say thermoquad or the variable-venturi for the 2V variety

Well, now, there is one Carter carb I was truly impressed with , the Thermoquad. Wish I still had it laying around. I bought in '77 with a tuning kit. Wicked nice piece.

Brandon, once you get done tuning that old Carter design, a Holley will be a walk in the park! Good work, keep on tuning!

1966_L78
Jun 29th, 11, 1:12 PM
#1 we know that your butt-O-meter is working.
how do we know?,,you installed another carb and felt the power difference..
I can always feel the power difference when i change timing or jets..and all i need is the US highway system and my first 2 gears..to get a great tune

Possibly an on ramp....I will floor it run it through 1st and feel how she pulls as i am watching how fast the tach needle is climbing..then at the sweet spot i grab second...i feel how well she recovers and run it up in the rpm range,,a lot can be felt in second...change timing and do it again..change jets and do it again and again untill you feel that there is no more left in it.....then play with cruise...you can fatten the rod in the cruise mode untill a steady cruise speed results in bucking or rough feeling...then "thin the rod" untill it is gone....perfect

I like to pull over on the shoulder on the highway..then do the accellerate test...of course out of the city limits..

"Butt-O-Meter; Not always accurate... years ago, we swapped from a VS Holley to a DP Holley, and while it "felt" much faster with the DP, the 1/4 mile ET was actually down a bit (several tenths, IIRC)... It had been "tuned" for a different car, and while you could feel the secondaries kick in on the DP, the rest of the tune was off enough to negate any ET improvement, even though it definitely felt a lot stronger (mostly just mid range where the secondary squirter was hitting)... After some tuning, the DP ended up being quicker in the 1/4...


I agree though, take it out in some deserted (safe) area, and play with it... Acalibrated "Butt-O-Meter is okay, but bring a stop watch. I'd bring a buddy too, so thye can run the watch while you drive the car...

1966_L78
Jun 29th, 11, 1:35 PM
I don't see too many Edelbrock AFB's in the pro stock ranks, they have the ability to test anything and you just don't see those shiny Edelbrocks sitting on those tunnel rams ;)

I have never seen ANY Pro-Stock car run a 650 DP? or any 4150/4160 carb...

AFAIK, they all run dominators... Then again, they have 500 cu in engines, manual transmissions, plenty of traction and don't need to run for more than a minute at a time...

Racecars run in a no-compromises world, they only need to idle while staging/and warming up, and them its just WOT...

Pro-Stock launch at WOT, and the engine/chassis can handle full throttle all at once...

What weight and stall RPM are we running here?

Buzzbomb
Jun 29th, 11, 3:02 PM
Im not worried about the power during regular driving or anything my main concern is 1/4 performance. Anything else Im just not concerned with at the moment, LOL. I see you went up (6) on your rear jets, which control your secondarys correct, did it perform at lot better as far as POWER is concerned??

Glad you're following up on this..So many times advice is given, and the OP never lets those know who tried to help what the deal was.

IF WOT- WIDE OPEN THROTTLE- performance, is ALL you are concerned with, IMHO you should do as you said you were going to do and try the 113 jet in the secondaries, and leave the primaries alone for now. You are already 5% richer on the POWER and no richer on CRUISE with a simple rod swap. Nothing wrong with that..Keep in mind that if you change the jet on the primaries to a larger jet, you are going to get a richer cruise mixture no matter what unless you actually drop jet sizes AND change rods.

I see the kit comes with the 113 and the 116 jets. 113 in the sec. will get you about 6% richer, 116 will get you about 8.5% richer. What you are doing here is what is normally done on a Qjet by switching out to a thinner metering rod or on a Holley by simply swapping jets. The secondary will probably give you the best bang for the buck and you can still have decent mileage. One thing you need to do is make sure the secondary "air door" is opening correctly at WOT. Sort of like getting rid of the infamous "Quadrabog" on a Qjet.

Geo71
Jun 29th, 11, 4:13 PM
@George....Wow thats cool man. I'm going to wait until this evening about 5-6 pm CT to play with it again. Im not worried about the power during regular driving or anything my main concern is 1/4 performance. Anything else Im just not concerned with at the moment, LOL. I see you went up (6) on your rear jets, which control your secondarys correct, did it perform at lot better as far as POWER is concerned??Yes when I first got this car it had a 305 with this 600 cfm carb on it. It was jetted way down. With some advice given here I put it back to the stock settings first. The front still has the stock 98 jet but I change the rod to the 73 x 42 and that helped alot, but the cruise is now alittle rich. Today I ordered a set of 75x 37 rods to try. So I can go back to the cruise I had before but richen the power mode.

Going from the stock 95 rear jet to the 98 helped so I went to 101 and that helped again. So I ordered 104 to try, hopefully that will work. I need to also check my fuel pressure and want to reset the float like you mentioned. Its definately alot stronger now. It wouldnt pull past 5000rpms before. Now I'm hitting 5800-6000 pretty easily.

Now that I understand these carbs better, they are pretty easy to tune. :)

jeff swisher
Jun 29th, 11, 5:57 PM
Quote:Now that I understand these carbs better, they are pretty easy to tune. :)

probably the same with anything..i was running the AFB's before the carter 9000 competition series was available people cursed the afb for years, i still ran them and beat many of my buddies,,i was the go to guy when it came to making things work excellent....then edelbrock put their name on them..all of the sudden they are the greatest thing in carbs...

Then the last 3 years or so a lot of people cursing them again...it's all about your quote.

Geo71
Jun 29th, 11, 6:39 PM
Quote:Now that I understand these carbs better, they are pretty easy to tune. :)

probably the same with anything..i was running the AFB's before the carter 9000 competition series was available people cursed the afb for years, i still ran them and beat many of my buddies,,i was the go to guy when it came to making things work excellent....then edelbrock put their name on them..all of the sudden they are the greatest thing in carbs...

Then the last 3 years or so a lot of people cursing them again...it's all about your quote.Yep you guys helped me out a ton with these. I'd been out of the car thing since about 1992 and was only familiar with Holleys. Alot different than the Edelbrock. They seem alot easier to tune now. Its pretty neat being able to tweak the different modes independently.

87caprice
Jun 29th, 11, 10:20 PM
OH MY FREAKING GOODNESS, Just Changed the floats to 1/4" from gasket, installed the .113 jets in the secondary with the .073 x .047 metering rods and took her straight to the interstate exit to exit. Luckily I live a mile from I-20 and each exit is a roughly a 1/4-1/2 mile apart and GOOD LORD that felt ssssooooo much better than what it did before. It creeps up to 6000 rpms alot quicker/easier now. The bog it had once I shifted to 2nd and climbing up the rpms is now gone. Man that was so much fun taking apart my Eddy alone and looking inside. Do you guys think I should try more metering rods and the .116 secondary jets?? Also should I bend the secondary rod to make them open up a lil bit quicker than they are. Cant thank you all individually so Im thanking you all in a BUNCH, THANKS FOR ALL THE HELP!!!!!

87caprice
Jun 29th, 11, 10:24 PM
Sorry but I overread on what Roland was saying about the secondary "air door". How would I go about making sure that is opening up at the correct time??

jeff swisher
Jun 29th, 11, 10:40 PM
I got chills reading your "OH MY FREAKING GOODNESS" post.

I love it when a plan comes together...I have never bent the secondary linkage unless it was keeping the secondaries from closing all the way.

I will tell you one thing i never feel the secondaries opening on this style carb you are playing with...The reason is when they are tuned right it is all a super smooth transition...

You can grind on the secondary air valve weights where they hang down in the wells....i have many spares to play with..if you grind some off and it dont like it then weld it back up...

But keep playing with the jetting for now....I usually gain nothing by having them come in sooner..i have even ran with it out..that sucked

I even tried no metering rods..another suck..but these are too easy to take apart and put back together not to try strange things

Buzzbomb
Jun 30th, 11, 12:21 AM
You've probably done what most Carter AFB/Edelbrock owner's DON'T do. Actually tune the thing for YOUR car. You hear a lot about how great it is right out of the box, and that's all fine, but tune it for your car and then you are getting your money's worth.

If it were me, I might put the 116's in the secondaries after driving it for a while and keeping an eye on the plugs with your current set up. I know the ideal way to check plugs is with a WOT pull and shut it off, but you can get some idea of how your jetting is by driving it for a time and checking them periodically. The thing you need to remember with this style carb is that you are working with TWO circuits. IF you keep messing with metering rods, you are going to have make changes to the jets to keep the cruise mix somewhere close to where you are. You haven't said much about the way the car drives at cruise, so I assume it's ok. There is a method to keeping the percentages in a certain range of lean/rich.

If the secondary air valve isn't really an issue on the Edelbrocks, do as jeff swisher suggested and leave it alone or do small changes. Since you eliminated a bog, you might have been running lean on the power mixture. Often times, if one suspects rich jetting, you jet it down until you get a bog or skip, and then jet it up a size. So, you could be right there on jetting now. You don't want it too rich either, FWIW.

So how is it now so far in comparison to the Holley? Just curious..

87caprice
Jun 30th, 11, 1:03 AM
@jeff....Yea it drives so much better with the little changes that I made today from what I posted. I ran out of time to try other jets and rods because I had to go to bible study then go workout but 2mar im going to try the .116 secondary jet and see how that goes. Well I dont feel too comfortable grinding on anything on my daily, lol, so I might just leave it as it is. It runs much strong/smoother than what it did.

@Roland.....The car drives wonderful now, much snappier and smoother now. The feel of it now makes me not wanna try that Holley anymore. Honestly, it feels about the same if not better than what the Holley felt like but I may be over thinking it right now because it feels so much better than what it originally did. But when I get back to my hometown this Friday, im going to try the Holley again on our test 1/4 mile (out city limits) road against my newly tuned Eddy 750. BTW, once I adjusted the floats today and added the secondary jets, the car has raised about 200 rpms at idle so I have to go back and adjust my idle mixture screws. Forgot to do it because I wanted to try it so bad. lol. I also have to adjust my choke correctly and after that, I should be ready by Friday night TNT. As far as the cruise, it still drives about the same on the interstate but I didnt get a chance to drive it that far on it but I know its much much smoother now at cruise. Im glad I went for this tuning thing which couldnt have been accomplished without the help of TC. I will let you all know how it goes 2mar when I get off work and put the other jet in the secondary but for now I have to go to slp, work at 6am.

1966_L78
Jun 30th, 11, 1:22 AM
Brandon,
Thats great... You have found what many have not. Properly tuned, the Edelbrock can be a great carb. There may be a time when you combo needs something better, and maybe a Holley would be called for, but likely with continued tuning that point won't occur until you combo gets really serious...

Look how far you have come in a few short weeks (or days really, since you got the kit)... Imagine having either a dyno,track ETs and or some other tuning equipment...

You've probably done what most Carter AFB/Edelbrock owner's DON'T do. Actually tune the thing for YOUR car. You hear a lot about how great it is right out of the box, and that's all fine, but tune it for your car and then you are getting your money's worth.


I think thats a point most hardcore "Holley" guys don't realize... I mean, there is a time and place when perhaps a Holley becomes a better choice for overall performance, but the Edelbrock is usually not out of the running for most street cars, when properly tuned.

jeff swisher
Jun 30th, 11, 8:29 AM
I cant wait for the back to back vs holley..
Tony wrote: Edelbrock is usually not out of the running for most street cars, when properly tuned.
Yes that is a fact....here is a fun story of 2 cars.
car #1 78 nova , 355 with ported 305 heads 1.72 intake valves 1.50 exhaust valves flattops and a tunnelram with 2 600 edelbrocks th 350 and 456 gears and 3" exhaust and a B&M converter that stalls to 2200-2400 and a little 280 comp cam NOT a ROLLER just the 280 magnum

VS the older 454ss truck the truck had ported heads a small cam and stock gears whatever they are..and with big mickey thompsons, the kicker it has a 671 blower with 2 750 holleys..

I built the nova for my buddy..all of it.. so everyone was trying to kick his butt and they came up with this dude and his truck..turns out my friend knew him...did not know his truck though...

race was on

They went to lunch first and discussed their rides and this guy kept putting down the edelbrock carbs... My buddy let it roll off his shoulders ..

When it finally happened the guy in the truck lost and had a couple comments,,, : Dang all i could hear when we took off was that 355 WWWWAAAAAAA and you were gone.. and whatever you did to those edelbrocks is spot on that thing flat moves....

This was after 3 races from dead stop to 40mph roll.
The nova ran 12.51 at the track with that set up.

The truck got faster after that with a cam change and a gear change and converter. and more boost..so did the nova with a cam and better ported 305 heads.
runnin 11.94 now with the same tunnelram and 600's, but the 454 truck is high 10's now

Geo71
Jun 30th, 11, 11:08 AM
OH MY FREAKING GOODNESS, Just Changed the floats to 1/4" from gasket, installed the .113 jets in the secondary with the .073 x .047 metering rods and took her straight to the interstate exit to exit. Luckily I live a mile from I-20 and each exit is a roughly a 1/4-1/2 mile apart and GOOD LORD that felt ssssooooo much better than what it did before. It creeps up to 6000 rpms alot quicker/easier now. The bog it had once I shifted to 2nd and climbing up the rpms is now gone. Man that was so much fun taking apart my Eddy alone and looking inside. Do you guys think I should try more metering rods and the .116 secondary jets?? Also should I bend the secondary rod to make them open up a lil bit quicker than they are. Cant thank you all individually so Im thanking you all in a BUNCH, THANKS FOR ALL THE HELP!!!!!Sounds like you are on the right track and making some progress, good for you!

That's interesting about raising the floats, I'm going to have to try that. Mine dies abit after hitting 2nd. I hope that's all it is.

I'd try the rear jets first and see how that goes. Drive the car alittle and check your gas mileage.

Highway Star
Jun 30th, 11, 11:28 AM
This is an excellent, excellent thread.

Nothing but great tech advice in here, and nice, VERY knowledgeable guys helping a fella get his tank running snappier.

Brandon, I'm pretty stoked to see you digging into this eddy and finding more horses. It is a great feeling to make your ride faster with your own two hands, isn't it? Glad to see you around, my friend.

Hook up that vacuum gauge, watch the tach, get your idle mixture set right, look at the float levels again, and you might find even more responsiveness out of that voodoo'd sbc.

87caprice
Jun 30th, 11, 1:09 PM
@Jeff....I didnt want this to get in a debate on the forum between Holly and Edelbrock as companys is why I chose to say this particular Holley carb vs MY Eddy 750. lol. I figured if I would've worded it differently, alot of guys would've maybe got into a piss match between which company is best and thats not what I had wanted to happen with this thread. Anyways, yes I will keep you informed on the difference between the two USED carbs I have access to. My buddy Holley street hp 750 mech secondary vs MY Eddy 750 electric choke. FROM HIS MOUTH, the Holley is tuned for his 388 stroker so Im not using an out of the box carb. But I wont be able to try em both until tommorow when I make it to my hometown where HE is. I will definitely let you know the differences between the two but I can tell you that as of NOW, MY CAR feels about the same if not better than what it did with his holley.

87caprice
Jun 30th, 11, 1:29 PM
@George... yes thats what my car was doing. Acting like it was dieing out when I get to 2nd and up in the rpms about 3500 & up it just felt sluggish at first but now it doesnt feel that way anymore. It really slowed my car down whenever it would do that. I dont know if it was just the float change or the all the changes together but that sluggish/dieing out feel is gone now. Im still not done playing with it and Im going to change the secondarys up again once I make it home after work and see how that does. Hopefully this next change will be for the best. I think you should try half the length of 7/16" and see how it does. I have a pack of Air Horn gaskets (5 pak) and if you need one just let me know and I can overnight one to you through Fedex if you dont already have one just for insurance.

@JAKE... HHHHEEEEEEYYYYY BBUUUUDDDDDDDDYYYYYY.. Thanks bro, I really dont like to take my car to a shop to get worked on especially when it comes to it mechanically. I've wanted to take it but with the help of the guys on here, I went after it by myself. Yes when I get home Im goin to have to readjust my idle mixture screws and check those floats again. And man the car is much much smoother/snappier now. I've just learned that I will never buy another carb and not tune it to my car. This was/is a great learning experience for me because I have a ton of friends and older guys that get rid of there eddys without ever opening them up. And they sell them for DIRT CHEAP. Maybe I'll buy them and tune them to learn more about them. BTW, HOPE TO SEE YOU NEXT WEEKEND...will be coming to Blue Bayou on the 8th for a little fun in the sun. lol. I wanted to drive my car there and take it to a dyno for further more tuning but kind of spooked to leave it outside of a hotel even though the clear coat is peeling and looking like a diary cow.

Geo71
Jun 30th, 11, 4:10 PM
@George... yes thats what my car was doing. Acting like it was dieing out when I get to 2nd and up in the rpms about 3500 & up it just felt sluggish at first but now it doesnt feel that way anymore. It really slowed my car down whenever it would do that. I dont know if it was just the float change or the all the changes together but that sluggish/dieing out feel is gone now. Im still not done playing with it and Im going to change the secondarys up again once I make it home after work and see how that does. Hopefully this next change will be for the best. I think you should try half the length of 7/16" and see how it does. I have a pack of Air Horn gaskets (5 pak) and if you need one just let me know and I can overnight one to you through Fedex if you dont already have one just for insurance.

I almost set the floats that way last time I worked on it, but figured going with the recommended setting first before I mess things up to bad. :D Mine didnt start doing this dying after second till the last jet change. I think its finally using up enough fuel to make this an issue. I placed an order with Summit this morning for a fuel pressure gauge, fuel filter and some other things. That should narrow things down alittle. It should be here tomorrow.

I was thinking of going to the track Sat, but its supposed to be in the high 90's with a ton of humidity. i may pass on that prospect. :)

What size engine do you have again?

Thanks for the offer on the gasket! I should be ok (crossing fingers) hopefully. But if all else fails, I'm only about an hour from Jegs.

jeff swisher
Jun 30th, 11, 6:32 PM
I know it aint no debate on which one is better, i just like the comparo's!

you should see some of the mods i have done to my holleys,,they will run, and once each is tuned to the best degree i usually notice little difference between the holley and carter and Qjet...just as long as it is flowing enough air for that engine.

When i test new combos and carbs i test all carbs and for my stuff that testing of 1 carb usually takes a couple weeks to make it really work under all conditions..
I aint prejudice:D

Buzzbomb
Jun 30th, 11, 7:17 PM
I have a ton of friends and older guys that get rid of there eddys without ever opening them up.

As suggested earlier, the above quote is the reason many have given Edelbrock carbs a bum rap. When attending a car show, one usually sees nothing but a sea of Edelbrock carbs, and suffice it to say none have probably been touched since they left the box. It just doesn't have the "hardcore" Holley image, and that hurts it. Heck, even a Qjet seems more hardcore than an Edelbrock because you have to know what you are doing to get those to work well. I don't know about you guys, but I hardly ever see Qjets at shows. That being said, when you get past that stuff, the AFB IS a pretty cool design. There must be something to it, because it was OE on many stock dual quad 426 Hemi muscle cars.

It is still a carb, and when tuned correctly for a specific app, there's probably not a ton of difference for a street car. You just have to put in the time, effort, and PATIENCE to tune the thing for your engine. I used to be a Qjet basher because when I first became interested in all of this, I had a POS remanu Qjet that was a Frankencarb. I found a nice core to rebuild, did it a *ahem* few ;) times, and became a real fan of the Qjet. Same is happening for the AFB style carbs..I like the way they operate.

I'm kind of looking forward to your TNT numbers :) ..Do you have a baseline from the last time you went? One of the cool things about the AFB design is that if you wanted to drive to the track and run it a few times with the 113's and then swap out to the 116 in the secondary, you can do it with ease and no spilt fuel. Might just cost you an airhorn gasket. Should be interesting!

jeff swisher
Jun 30th, 11, 7:53 PM
qote:it was OE on many stock dual quad 426 Hemi muscle cars.

And for you gm guys here it was also stock on 1962-65 409" Eng w/2 four barrels and that same time the 327" was offered with the carter AFB in the higher horse like the 300 and 340 HP
Go on back to 1958-61 the 348" Eng. Spec. Turbo-Thrust, had the afb or wcfb...This design has been around a long time..I actually have some from the early 60's one that was from a big buick..
I grew up on these carbs, but that is because all the old fogies i hung around with had them on their rides..but they usually had 2 of them metering "go go juice" as they called it.

sorry for the blast to the past, i could not resist

matt's66
Jul 1st, 11, 8:00 PM
This is an excellent, excellent thread.

Nothing but great tech advice in here, and nice, VERY knowledgeable guys helping a fella get his tank running snappier.

Brandon, I'm pretty stoked to see you digging into this eddy and finding more horses. It is a great feeling to make your ride faster with your own two hands, isn't it? Glad to see you around, my friend.

Hook up that vacuum gauge, watch the tach, get your idle mixture set right, look at the float levels again, and you might find even more responsiveness out of that voodoo'd sbc.
x2. Good thread. I love my Eddy carb. I'm going to try the float trick when I get some spare time.

87caprice
Jul 2nd, 11, 7:41 AM
Ok guys I finally got a chance to put it on the road for a drive on my way home yesterday. 1.5 hr drive with a avg mph of 75. As far as the power while driving, it passes much easier now with less go pedal and the gas mileage seemed as if it was still the same if I could've kept my foot out of it. Lol. But overall driving it seemed better than before....BUT....and we all know a "BUT" was coming right? I am having a problem now with flooding once I try to get going as in I crank up the car and start to take off either regularly or agressively it floods out and I have to pat the gas to make it stay on. I'm don't know if its the floats adjusted that way or not but it didn't start to do that until I adjusted the floats and changed secondaries. Will go after it this morning to move floats back to 7/16 and see how it acts. Didn't get a chance to play with it yesterday bcuz my son wanted to play so I will go after it when I leave the barbershop this a.m. Will keep you posted. Btw, could someone tell me how did you come jp with those percentages when changing jets? Like an equation/formula.

87caprice
Jul 2nd, 11, 7:44 AM
Forgot to mention, it doesn't flood out all the times either. Maybe once out of 10 take offs.

jeff swisher
Jul 2nd, 11, 10:50 AM
To be honest i have never used anything but an eyeball measurement on my floats...
I start with the air horn upside down with the gasket in place and floats installed......
I want the floats to be level with the gasket for a base setting,,,if i feel i need a tad more fuel i will bend them so that they are almost level but you can tell the end furthest from the needle and seat is closer to the gasket,,,,,

Now if i am going for a mileage thing i will bend the other way,,but just a tad,,if i get driveability issues i will go the other way .

I have even set the float on the accellerator pump side to have deeper amount of fuel there for driving and starting on steep inclines..


I wanted to share an easy way to get the jets in and out,,,,after you unscrew the jets use your metering rod to fetch it out,,just the pointy end inserted into the jet then walk it up the wall...when installing the jets slip the jet onto the rod and hold it and insert the rod into the empty jet cavityand let the jet slide down into the hole.....this way they are right side up and you do not need to try and flip them...

every 2 years my carbs get new needle and seats...i have found they seal off better like this.
I have always ran 7.5psi to my carter afb's and no problems,,,i will go check my truck later and see what it is...I run stock AC or carter mechanical pumps with 3/8" fuel lines and never had fuel issues.
no regulators..our 78 nova with 2-600 edelbrocks runs an ac pump with times at 11.94 i have seen zero problems...my other nova was quicker and same deal....make sure the regulator does not varry pressures...

Geo71
Jul 2nd, 11, 11:10 AM
Forgot to mention, it doesn't flood out all the times either. Maybe once out of 10 take offs.Sounds like you might have a piece of dirt or debris in it. I think the instruction manual says something about it.

kirkwoodken
Jul 2nd, 11, 12:03 PM
Back in the stone age, when 3X2 barrels were the hot set up, most were using old Ford Strombergs for carbs. The guys I knew discovered that the Carter's used on early Olds engines had much larger venturis, but the tops had to be cut off to allow them to fit on the manifolds, as they had a long snout that ran parallel to the engine centerline. That was my first experience with Carters.

The next was with the 2X4 setups with WCFB Carters, which came on the high performance 283's. Both of those together had 8 square inches of venturi area, which was the same as one AFB. I got my first 327 in the fall of 1961, and stayed with the 2X4 setup, figuring the fuel distribution would be better than the single AFB manifold, since the venturi area would be the same. That must have been true, because I beat EVERY single 4 that I raced, either from a standing start or a roll. The two small carbs ran better than one large one.

Later on, I ran two AFB's on a 360 degree Offenhauser manifold, and set a strip record in my class at that time. And my 6-71 blower setup had two AFB's because they fit on the top well.

I have never been disappointed with the performance of Carter AFB carbs, what is now the Eddy. If my memory is correct, when Edelbrock bought the Carter rights, they had John Bathe look over the design, and he made some minor changes in it. Maybe someone who knew John could add something to this.

I still use an AVS on my 406 occasionally, and it works well.

Sounds like Swisher and I came from the same neighborhood. You youngsters have no idea how much fun you missed. Most of us are self taught to some degree. We had no fear of making mistakes, because trial and error was just the way things used to be done. Today, many want to buy the knowledge of others instead of acquire it themselves. This is a concept that is foreign to some of us old guys. Everybody seems to want that 8 second street car without ever self-building a 12 second street car.

It gave you a good feeling when you took a 15 second factory car and turned it into a 13.5 car just by tuning. I did this at the track with a guy's 390 Ford, and he just couldn't believe it. Same for the Z/28's that ran low 15's from the factory and mid 12's with tuning.

1966malibu
Jul 2nd, 11, 1:50 PM
Brandon go back to your stock float setting and check your fuel pressure with a gauge at the inlet. The two settings are very much interrelated. If you have to much fuel pressure the needles will be lifted right off their seats. If the floats are not dead-on then they will cause you to have to much or to little fuel in the bowls. Which can cause starvation issues or flooding. The one thing I have learned about these style of carburetors over the years is that they are very touchy about their fuel levels.

As for the best tuning procedure you need to have some place that you can time your cars performance. The track, a dyno or even yourself with a stopwatch will work. look at the chart that came with your Eddie. You will notice that the #1 setting is the stock one. In most cases if you stay in the shaded area and move up or down one or two steps it only requires a rod change. They did this intentionally. If you car requires more fuel, then after you have made a base (time,speed or hp) measurement move up the chart one space. If your time improves move up a additional setting. If it still is improving THEN change the secondary jets one setting and bring the primaries back to there first setting. repeat this until you find and setting that there is no change. Then go back to your last and you have just tuned you carb for WOT. Cruise mode adjustments can now be made by looking at your chart and making changes to your rods up or down on the chart. Any transitional problems (IE rolling into the throttle) can probably be fixed with a spring change. All these adjustment should only be done when your timing and tune up specs are already were you want them.

I have found that the best thing about a carter style carb is how quickly you can get it into tune. The second best thing is how well they hold it ;).

Buzzbomb
Jul 2nd, 11, 4:23 PM
You could perhaps have run into one of the downsides of the Carter style carb, and that is fuel percolation. That can sometimes cause hard starting. What sort of base gasket(s) are you using? I can tell you the secondary jets have nothing to do with the issue you have now. It could be the float level, buf if you change it to the stock level and it still does it, you know that wasn't the problem.


What do your plugs look like now as opposed to before the changes? I wouldn't be making willy nilly changes just because you have jets and rods. It's best to do it in a measured way, and as stated above, according to a stopwatch or dragstrip time. It's basically like a rolling dyno tune using your four wheels and a stop watch as the measurement tool. I don't like the Edelbrock chart, FWIW. It's not exact enough and limited in scope, IMHO.

If it were me, I'd make this a process. Keep it where it's at for now, take some notes on the performance. If you want to make a change, make a small change, and then see if it improves. Rinse and repeat...

You guys all bring up valid stuff about why the Carter AFB is a decent performance carb. It's been used on numerous OE hot rods as well as by people who believe in the design. Let's face it- when you see them on numerous cars at a car show with 36 inches of rubber fuel line from the floor pan to the carb driven by some guy or gal who you know has no clue, it sours you a little on it. There are just SO MANY of them out there and many times people sort of look down their nose at stuff like that. I've done it myself until I actually looked past that and explored the design a little further. It's a neat carb with a lot of potential to be a very precise fuel metering device.

87caprice
Jul 2nd, 11, 6:44 PM
Ok I'm back again guys. I've adjust the floats back to the recommended 7/16 that eddy says and drove it for a while and the flooding issue is GONE. Its back to cranling on back up and the notorious flooding is gone once I take off. Btw, I'm using my phone to type this so bare with me. I'm on my way out now to test it with the stop watch and see how it does. Will make 2 1/4 mile passes and come back hpme to let you know the time and any problems I may run into. This will be with the .073x.047 rods and. 113 rear jets. Be back shortly.

87caprice
Jul 2nd, 11, 9:23 PM
Well I tried it 3 times instead of 2 with the stop watch. 1st time shifting 6000, 5800 then 3rd it said 13.78.....2nd time shifting the same it said 13.29.........final time shifting at 6500,6000, then 3rd gear it said 12.87. HONESTLY I MAY HAVE BEEN COMPLETELY WRONG USING A WATCH STOP WATCH. Those times cld be all over the place, I don't know but those are the test numbers that I got. I am tryn to get it to the track tonight to really get some times on it.

jeff swisher
Jul 2nd, 11, 9:51 PM
Track time would be awesome..and only change 1 thing at a time no matter how bad you want to try 2 or 3 things at once..
I usually had a buddy to race and we would only tune 1 car at a time.. old back roads...then the track opened close, 50miles, and i was there a lot.

Even there on opening day...I never spent money on a dyno,,but put a bunch of passes on the track

87caprice
Jul 14th, 11, 11:35 AM
UPDATE: The carb is tuned pretty good. Im running the current .073x.047 rods with .113 rear jets. I tried the .068x.047 rods and it felt like it picked up more but I didnt change the front jets out so I put the .073x.047 rods back in. I have been tryin 1 thing at a time and it seems like whenever I try it, it turns out GOOD as far as performance but hasnt had a chance to pay attention to mpg. I rechecked my timing also and my timing was wwwaaaayyyy off. I had an old timing light checking it with at first at it "said" 34* which was WRONG. I tried 2 different timing light from 2 different buddies and the timing was saying 30*. WOW, big difference right. So i turned my timing up to 36* and drove it hard, no pinging at all. Will try higher timing to see what else I can get out of her but is it safe driving with timing setup high like that???????But the rear tires are always spinning when i get down on it. GOOD THING! lol. It almost got away from me on a turn (full 180* in middle of street) luckily I was in front of my house when it did that. Wasnt expecting that at all and neither were my old buddies that was out there watching me play with the carb. After I played with the carb and adjusted the timing thats when I scared myself with the little 180* and scared them too. The car has NEVER done anything like that since I started building on it. I took it back out on our 1/4 mile strip (out city limits road) and tried it again with my lil sisters stop watch and this time is was spinning badly and the best times out of 2 trys was 15.xx secs. Im going to put the .068x.047 rods with 107 jet back in maybe this weekend and see what she does with the full jet change also. ANYONE who is reading this that owns a Edelbrock carb, I highly suggest you get a tuning kit for it and tune your carb before you go out and buy another carb.

OAN:: the Holley carb I tried at first, I retried it and it doesnt stand a chance. The car feels more powerful and smooth with my tuned Eddy. (still not done tuning)

jeff swisher
Jul 15th, 11, 2:57 AM
you have vortec heads..i would think the added timing would not make a gain in the right direction...but i have never ran vortecs...I can say i have built a couple 350's with old style chambers and have ran as much as 42 total....

answer me this..i went back to the first post and something dont sit right with me..that is your compression ratio..How deep are the valve releifs in those pistons and or how far down the hole are they to get only 9.8 compression with 60cc heads on a .060 over bore..

you wrote: 350 bored .060 9.8:1 cr
4vr flattops
Ported/polished vortecs, 2.02/1.6 valves, milled 60cc, 3 angle VJ, bowl blend, etc
.028 head gasket

Glad she is working well for you...the ride sounds happy:thumbsup:

87caprice
Jul 15th, 11, 10:11 AM
The pistons I have in the engine are like a stock replacement flat top, part #H345P and they are .025 ITH. The headgasket I have on now is the GM 10105117 .028 gasket. The heads have had LOTS of work done to them and the guy that did them got a final measurement on the chambers at 60-61cc. I read on here or somewhere that you can use a syringe and a cd to measurement the chambers and so I measured a few of them for $hits and giggles when i had the heads off and they filled with 60cc of water. I put my info in on a compression ratio calculator a year or so back and that is the number it gave me with the information given UNLESS I was doing something wrong. I know for sure the car DOESNT like 87 gas and barely likes 89, runs much smoother/better with 93.

berner
Jul 15th, 11, 12:01 PM
This is a great thread. Thanks for following up with your results. I've been leaning towards a Holley 670SA but might have to rethink an Eddy after following this thread.

jeff swisher
Jul 15th, 11, 3:51 PM
Not saying you are not correct but my math dont jive...i used the keith black united machine compression ratio calculator....it is usually with in a tenth or so....
I punched in your 61cc heads 4.1" diameter gasket and .028" thick and .025 deck clearance and those pistons have 6cc valve releifs..3.48 stroke...i get 10.4..which is usually how i build my stuff.....not that it matters it is what it is....you would need to be .050in the hole to get 9.8.

I bet she runs like a scalded dog...i was wondering at what rpm does the engine like to be shifted at?
Curious because i have never ran that cam..

87caprice
Jul 15th, 11, 9:28 PM
Wow thanks Jeff guess I've finally learned my actual compression Ratio. But I do know that they are .025 DITH and every thing else I mentioned is what I have to the T. Guess my calculations were wrong and when I did it, it was my first time ever using a ratio calculator. But thanks for the correction.

Yes she runs pretty good to be moving this big 4door that I have. And honestly, I dont know for sure WHERE SHE LIKES to be shifted at but I normally shift it at 6400 rpm (just before 6500) because I am afraid to tear something up. And shifting it at 6400 she is STILL PULLING, nose of the car nevers drops. How would I be able to find a sweet spot where she likes to be shifted at?? Like I said before she runs completely different when Im using 93 octane and ok when running 89 but not worth a darn on 87 and a bunch of pinging. Can barely drive it with 87.

kirkwoodken
Jul 15th, 11, 10:53 PM
1966malibu wrote:Jeff your giving away all the secrets :D

Not all of them ,,and most people aren't that enthusiastic.

And the avs is an excellent carb..and do not forget the dreaded thermoquad,,,very tuneable,,if there was ever a red headed stepchild of carbs i would say thermoquad or the variable-venturi for the 2V variety

I still think the Thermo-Quad was the best 4bbl made. If only they had made them from slightly better material, I think there would be a lot in use today. Carter always made good mileage carbs.

An old friend had two AFB's on a 260, roller cammed, Ford that ran in the mid 12's way back in the stone age. People had a hard time convincing him that it shouldn't run as well as it did.

The "Rule of Thumb" back in the stone age was one square inch of venturi for every 35-40 cubic inches, so by that standard, the 260 was WAY overcarbed. Guess it didn't know better.

The youngsters are saying,"What's a Thermo-Quad?"

jeff swisher
Jul 15th, 11, 11:17 PM
The youngsters are saying,"What's a Thermo-Quad?"

that's funny aint it. some of them TQ's would not come apart with out destroying them

I still like lots of carbs..just the way i grew up. but i was also preached run lots of compression and port the heads..duration was king and lift not so much..more of-- lots of overlap.

To find the sweet spot takes some races...watch the et and mph.

DO NOT let it ping..this will recess the valves in short order..not to mention what it does to bearings
if you get stuck somewhere where there is only cat piss for fuel , run it but keep your foot out of it or pull the timing back till the ping quits.

I will early shift to high gear and roll into the throttle(kick down disconnected) and see if it pings...pull it back till she is gone..that is usually a good starting point

I built a 355 for my buddy..76truck mid 11's with 411 gears on 91 octane..lasted untill he screwed with the timing..35 on the ballancer and dial back timing light on 35..yes sir that is 70 total...nothing can take that for long.POINT IS..he could not hear it ping because the 4" exhaust that he built and thought was soooo cool...

how69ss
Jul 16th, 11, 9:18 AM
I rechecked my timing also and my timing was wwwaaaayyyy off. I had an old timing light checking it with at first at it "said" 34* which was WRONG. I tried 2 different timing light from 2 different buddies and the timing was saying 30*. WOW, big difference right. So i turned my timing up to 36* and drove it hard, no pinging at all. Will try higher timing to see what else I can get out of her but is it safe driving with timing setup high like that??????? .





To find the sweet spot takes some races...watch the et and mph.

DO NOT let it ping..this will recess the valves in short order..not to mention what it does to bearings


Brandon,

Nice going on tuning that carb!

Like Jeff says, you don't want detonation. I wouldn't mess with the timing until you can get on a track and move it one degree at a time. You just can't tell from the way the motor sounds or even the butt-ometer. I bumped my timing up 2 degrees one time and I thought the car sounded great, ran real good down the track, I thought. But my ET was .4 slower in the 1/8. You really need to test it on the track.

Other thing is once you get to the track, don't even change one thing until you get some consistent runs. I think that happens a lot. I've done it in the past, too. You have to have your driving and the car consistent just the way it sits and then, like Jeff says, change one thing at a time, and even make two or three runs with that one thing changed. Of course if you change it and drop .4 ET, and everything else in the run was good (good burnout, hooked, shifts hit), then you only needed that one run and you move to the next thing, etc.

scott

how69ss
Jul 16th, 11, 9:21 AM
Brandon,

One other thing you might run into. On my edl carb I had to insulate the edl fuel line and filter in the summer. I used that foam-type plumbing pipe insulation you can get at Ace Hardware or wherever. It's not pretty, but it works.

Scott

Bob West
Jul 16th, 11, 11:46 AM
Once you get done with the Edelbrock, spend the same amount of time tuning the Holley with the timing adavanced and the Holley will win again. Your test track leaves alot to be desired, no accurate data on anything, just wishful thinking on thread participants ;)

87caprice
Jul 16th, 11, 12:31 PM
@Scott...Everytime I set a plan to take it to the track here something else always comes up where I dont get a chance to go. I would really like to go today since last night was TNT, but I just know if I say "ok im going to the track tonight" something is going to come up where I cant go. I understand what you and everyone has said about the track and tuning but EVERY SINGLE TIME i've planned to go, it never went through. Also what does the insulation do to the fuel lines?? I've never seen or heard of that around these neck of the woods. lol

@Green Weenie....lol....I wish I could tune the holley but its NOT my carb and I dont think he would want me tuning his carb out of whack from his engine. But im not done with the eddy as of yet. I can give you guys an estimate on my gas mileage today once I make it to my hometown. Full tank of gas now. Will fill it back up once i make it to hometown and about a 92mile drive. Will be post how many gallons I had to buy to put it back on F.

Bob West
Jul 16th, 11, 12:53 PM
Take it to the track and do some actual back to back testing to get my attention ;)

1966malibu
Jul 17th, 11, 4:49 AM
Being a Carter fan (note my choice of words) I just wanted to throw this out to all you Holley fans.

Back in the day Holley and Carter were both winning at the track. Holley wanted to be the best fuel metering system around. So they started a ad and contingency campaign that was second to none. The bonus monies that Holley put out caused many Carter users to switch (Carter did not have such a good pay out) to stay competitive. As more people learned how to make the Holley work and win races. More aftermarket companies got involved. This made The Holley the go to carb if you wanted to go fast.

A good analogy of this would be what happened to video tapes back in the late Eighties. Beta was a better format but VHS won out because it had a better backing by aftermarket companies(now I am not saying that a Carter is a better carb, but ;)). But then both lost out when we were told that DVD's were even better :D.

So just remember that there were a lot of very fast "factory" cars that were running with a Carter style carbs. But thanks to a very clever and well backed campaign by Holley we were shown what the best carb was by Madison Ave ;).

PS. Just a thought If VHS and Beta were both replaced by something better. How long will it be until Holley and all other styles of carburetors are replaced by something better? Hopefully we will not have to rely on a ad campaign to tell us :sad:.

ChevelleFan70
Jul 29th, 11, 12:03 AM
I've followed this thread with much interest. I bought a new 1406 for my dad's Vortec 350-powered Vette a couple months back and was looking for tuning info. Two weeks ago, I found a good-condition 1407-750 at a swap meet for $30 and brought it home.

You mentioned not being able to get to the dragstrip, and you made one of your posts from your phone. If you have an Android phone, there's a free app in the Market called "aDyno". It looks like it would provide more reliable/consistent info than your stopwatch testing. You just need a way to securely mount the phone in the vehicle. Holding it or leaving it on the seat won't be good enough. It's not a dragstrip, but it might be enough for your purposes.

http://adyno.net/forum/

-Dave

1966_L78
Jul 29th, 11, 4:57 PM
Once you get done with the Edelbrock, spend the same amount of time tuning the Holley with the timing adavanced and the Holley will win again. no accurate data on anything, just wishful thinking on thread participants... Take it to the track and do some actual back to back testing to get my attention ;)

I agree about getting some good data... I wish some magazine or other "impartial" source would do a test on all the various types of carbs out there... Maybe both on a dyno, and at the track. Something with the same car, back to back to back to back (etc)... I think then we'd see that the Holley does not offer the big advantage many think...

My buddy had a "professionally tuned" Holley VS, and it ran great... He swapped a nice DP (same size), and that thing hit hard, throw-you-back-in-the-seat hard... But when we took it to the track, it actually had slower ETs (IIRC, 330 ft and maybe 660ft were better, but 1000 ft and 1320 the VS won)... Like many people, we just assumed that the DP kick meant it was quicker, but it wasn't true... It was a "race" carb, how could it not be better?

Thats not to say the Holley isn't better suited to maximum performance (no compromises), or that certain designs will dominate for certain situations (such as the Double Pumper being the obvious choice for no-compromises racing)... Alot of racers feel the Holley is always the hands-down winner, but relatively few of these guys have ever played with a different carb...

Bob, have YOU ever performed a back to back test, tuned Holley to a tuned Edelbrock? Or maybe not a "back-to-back" test, but just a "tuned" Edel to Holley swap, and have any data? Have you ever tuned and ran an Edelbrock at all? Any data you'd like to share?

I have done at least 5 swaps from Holley to Edelbrock, and with only limited tuning (many a rod change or step-up springs) the Edelbrocks ran with, or even better than the Holleys... Now these were "street" cars, no drag radials, no fancy suspension pieces for a better launch, and not very consistant, but ETs were similar or consistantly better with the Edel. And every driver loved the way the carbs performed on the street as well... Now, most of these swaps were done back when the Holleys had issues with blowing power valves, and I'd usually get called to change those out, but the Edelbrocks were dead-reliable (had one 750 that was returned under warrantee, but thats it). IMO, not much sense idealizing the WOT launch with a DP when the tires and chassic/suspension can't handle it all at once...

Ironic, many people "think" the Holley is automatically better (with little to no supporting data), yet when I posted about my Edelbrock going quicker than my DP (Mighty Demon, not a Holley), people gave me crap about not listing my DA, etc... I wasn't anticipating a back-to-back swap, just stating the facts that my car went quicker with a higher MPH with the Edelbrock ( and my track doesn't show them on the time slip)... Now, I never tuned the Demon, but the sellers had lots of race parts, bought some motors from Mike Lewis, swapped heads and cams looking for power, etc, and seemed to know his stuff. The car ran great, so I assume it was decently tuned...

I honestly did the swap for better driveability and fuel economy, as the DP had HORRIBLE mileage (part of which was how fun it was to hit the secondary squirters and smoke the tires at a 25+ mph roll)... I figured I'd drop a few tenths at the strip, but was fine with the trade off for a mostly street driven car. I was shocked to find the "out-of-the-box" Edelbrock not only had better ETs (much attributed to a softer hit on the tires out of the hole), but actually MPH consistantly higher (1-2 MPH). I was told the MPH was more an indicator of power...

Now, the carb wasn't the only change I made. I did swap on an Edelbrock fuel pump and a Summit HEI w/vacuum advance (module removed-Summit CD ignition box installed), in place of a mallory Magnetic-breakerless distrib with "locked out" timing and an MSD 6A box). The runs were several months apart, but in subsequent trips, the car still performs better than it did with the DP... the best run, 12.34 @ 110 mph, was the fourth of the day, after "hot-lapping", 4 runs in only 20+ minutes! (2010 WCCG, Chevelle only lane)...