1" carb spacer...what does it do? [Archive] - Chevelle Tech

: 1" carb spacer...what does it do?


Grape Ape
Dec 19th, 04, 12:21 PM
What does the 1" carb spacer under my holley 750 DP on top of a Edelbrock victor JR. accomplish?

It is on a Moderately built 350 (sorry I don't have specifics) that is having problems running rich and loading up at low RPMs.

I understand that I could be timing and or carb adjust but had read something that tunnel rams(obviously much taller) cause problems at low rpms with too much gas too soon. I don't race but I do like power..like all of us do.

In other words what does the spacer do and should I take it out?

Thanks for the help.

Motor Martyr
Dec 19th, 04, 1:35 PM
what plug and heat range?

Grape Ape
Dec 19th, 04, 1:53 PM
I'm sorry I don't know. It has the accel plugs that I bought it with.

Motor Martyr
Dec 19th, 04, 2:13 PM
those things are junk, toss them and buy Autolite plugs in a #3 heat range.
Tell me the reach and seat of your plugs, and i'll make a recommendation.

Those junk plugs are one of the reasons that the engine is loading up. My brother had a set of those in the engine i built for him, and it would gas foul them out very quickly (mild engine too). ***** canned them and switched to an AP-25, and the engine runs clean.

If that doesnt clear up the problem, then you're just wayyyy rich at idle. I like them to be rich at idle, but not wayyyy rich.

Does your carb have 2 corner idle? If so, after putting the new plugs in, warm it up then turn the driver side idle screw in until the engine starts to surge, then back it out 3/4 of a turn.

Set the other side to the same spot, then do it again, and again reset the other side. Should be at 1-1/4 to 1-3/4 turns out depending on how mild or wild this motor really is.

BTW, very nice looking car, i've checked out your pictures and the car is very nice and clean looking.
One suggestion of mine is to change your coil mounting to the upright position.

Grape Ape
Dec 19th, 04, 2:40 PM
Thanks for the thurough input Brian.

Just_Another_Mike
Dec 19th, 04, 2:45 PM
From my personal experience the Victor Jr. is not "street friendly" manifold. I wouldn't run one unless I had a very aggressive cam, low gears, high stall, and high compression. I used one on my daily driver for 10+ years and it always ran slightly rich, but it was a good manifold for high rpms. Another suggestion is to get your timing dialed in and make sure your distributor is curved to match you setup. Yet another suggestion is just to take out the spacer and see how your car performs.

Mike

Motor Martyr
Dec 19th, 04, 2:51 PM
no problem, let me know how it works out.

Let me know the plug construction and i'll make a plug recommendation.

Just_Another_Mike
Dec 19th, 04, 2:53 PM
oops

Slowpoke70
Dec 19th, 04, 2:53 PM
Brian, do you happen to know of any alternatives to Accel's Shorty "Header" plugs? I really did like my ACDelco plugs better, but getting the #6 plug was a PITA with the standard length plugs and my Hooker headers.

Even Dynomax includes a little paper with their new headers that says to use an Accel Shorty in the #6.

Motor Martyr
Dec 19th, 04, 2:58 PM
Yes, what makes those plugs "shorty" is the lack of a resistor.
An Autolite "racing" plug, earns its "racing" status by removing the resistor and cutting back the electrode.

An autolite "racing" plug is the same lenght as an accel shorty.

I have the same clearance problem, and currently run an AR-135 plug, however i'm going back to an AR-13 plug, which i feel has been more successful in my car.

The autolite plugs are a much better plug, if you chose a racing plug, get one in a heat range that will be streetable.

blazerbob
Dec 19th, 04, 4:26 PM
Carb spacers add plenum volume to manifold. Generally they decrease power below torque peak and add power above peak torque. I would spacer only for all out hp in racing application. And the only way to tell if they help each application is to track/dyno test on motor.

Grape Ape
Dec 19th, 04, 7:12 PM
So if I understand you correctly Bob I should remove the spacer for street driving and if I want more low end power. Am I understanding you right?

Thanks

Wolfplace
Dec 19th, 04, 7:31 PM
Originally posted by Grape Ape:
So if I understand you correctly Bob I should remove the spacer for street driving and if I want more low end power. Am I understanding you right?

Thanks Engines don't read the same magazines some of us do soooo,,, :D
To repeat part what Bob said, the only way to know if a spacer will work is to try it under controlled conditions.
From the way you describe your combo, I would say it would like an RPM or RPM air gap intake.
The dual plane will also make the engine think the carb is smaller which is probably a good thing in your case.
If nothing else, try a four hole spacer & no spacer but you will need to do it at the track or on a dyno.
I have seen everything from a loss to about 20HP gains in spacers in different applications.
You are increasing plenum volume & you are also changing the distance to the carb which changes the signal it sees from the cylinder which changes how the engine reacts to the cam,,, the list goes on ;)

BigRed-L72
Dec 19th, 04, 8:36 PM
Originally posted by Motor Martyr:
those things are junk, toss them Why?(the accel plugs)

The shorty plug is "shorter" btw

Motor Martyr
Dec 19th, 04, 9:02 PM
i've explained my experience with those plugs in my other posts.
Again, here's my experience with those plugs in a mild small block, they were gas fouled after firing the new motor, chucked them and put in a set of AP-25 spark plugs, which are still clean.

BTW, the shorty plug is the same length as an autolite racing plug, i've matched them up, if not then they are close enough.

You wont find those in any real race engines, infact Bruce Allen's pro stock features autolite racing plugs in a #3 heat range with a non-extended tip.

LXS
Dec 19th, 04, 9:24 PM
Not trying to hi jack this post, but, what heat range Autolite plug would be good for my daily driven 388ci? Specs, really quickly are...
9.5:1C/R, ported Bowtie heads, 2.02/1.60 valves, .488" lift cam, RPM intake, Holley 750VS 3310 carb, Hedman 1 3/4" headers, TH350 tranny, Holeshot2000 converter, and 4.11s out back...I think that's everything. I'm currently using those Accel shorties because of clearance problems, what heat range do you recommend for me? All motor and daily driven, thanks! graemlins/beers.gif

Motor Martyr
Dec 19th, 04, 9:35 PM
I vary it depending on a few situations. If the engine runs hot, generally i'll select a colder plug, since a hotter engine will be more prone to detonation, and a colder plug wont be.

Email me at SpeedyGoomba@yahoo.com, as i need the specifics.

BigRed-L72
Dec 19th, 04, 11:01 PM
Originally posted by Motor Martyr:
i've explained my experience with those plugs in my other posts.
Again, here's my experience with those plugs in a mild small block, they were gas fouled after firing the new motor, chucked them and put in a set of AP-25 spark plugs, which are still clean.

BTW, the shorty plug is the same length as an autolite racing plug, i've matched them up, if not then they are close enough.

You wont find those in any real race engines, infact Bruce Allen's pro stock features autolite racing plugs in a #3 heat range with a non-extended tip. :rolleyes: :rolleyes: :rolleyes: btw... you`re trying too hard graemlins/sad.gif

Motor Martyr
Dec 19th, 04, 11:06 PM
Trying to hard? LOL, Unlike many, i do a ton of research on the decisions i make.
I've tried 5 different spark plug configurations in my engine to find the ones that i really like best. AC-43, AR-12, AR-13, AR-135 and AP-25, So far AR-13's are my favorite, with the AR-135's as a close second.
I actually took a picture of the spark plugs on the reher morrison carb tray in the pits sitting on their 500" pro stock motor. put the part number into a search engine and found the plugs and their construction!!! Autolite AR-473

Trying to hard??? maybe, sounds to me like doing research.

Afterall it's the small details that i've taken care of that really make this car enjoyable to drive, easy to start, run well, and powerful!

Why do you feel compelled to comment on this post, and infact most of the posts that i make?

Is this because, myself and my friend do not believe the story about the 3760lbs camaro?

baddbob71
Dec 20th, 04, 12:53 AM
I've seen problems with the accel plugs on two different engines, not sure why but they sure didn't spark like the ac plugs that replaced them. I've seen NGK plugs that had problems as well, at forty bucks a set. No experience with autolites but have only heard good things.

Georgia69
Dec 20th, 04, 10:59 AM
Originally posted by LXS:
Not trying to hi jack this post, but, what heat range Autolite plug would be good for my daily driven 388ci? Specs, really quickly are...
9.5:1C/R, ported Bowtie heads, 2.02/1.60 valves, .488" lift cam, RPM intake, Holley 750VS 3310 carb, Hedman 1 3/4" headers, TH350 tranny, Holeshot2000 converter, and 4.11s out back...I think that's everything. I'm currently using those Accel shorties because of clearance problems, what heat range do you recommend for me? All motor and daily driven, thanks! graemlins/beers.gif You don't have to buy the race plugs for a street engine. I use Autolite 23 or 24 for tapered seat heads, and 3923 or 3924 for gasketed plug heads. Try the Autolite 23 in your Bow Tie heads, I used to run Bow Ties and the 23 worked mint.

Slowpoke70
Dec 20th, 04, 2:11 PM
I think the reason we want to run the race plugs on street engines is due to hearder-to-plug clearence. Although, Alex has angle-plugged bow-ties so that might be a moot point for him, he may have clearence.

On the other hand, I wish I could run ACDelcos but the boot end up too close to the header tube, and no sparkplug socket will get in there with a standard spark plug. Don't know about you guys, but I'd rather not have pull my headers or break spark plugs to get them out.

LXS
Dec 20th, 04, 4:00 PM
Even though I have angle plug heads, my primaries are shaped weird, leaving me with little room to spare for "normal" sized spark plugs. The main primary that gave me a headache was for the #3 cylinder. I had to bend/dent that primary until I was able to get an Accel shorty plug to fit. As for the other primaries, I don't recall as to how much clearance I had, but I do know that there is just enough room for the shorty plugs and plug boot to fit.

Grape Ape
Dec 22nd, 04, 8:37 PM
Thanks for all the feedback.
We found that the coil was not putting out a hot enough spark to take advantage of my MSD Box and dist. Additionally the weights in the dist were sticking...obviously this causes a timing issue.

So we are putting in hotter plugs. Hotter coil, taking out the 1" carb spacer, cleaning up the distributor so the weights work properly, new cap an rotor (which were toast), and adjusting the carb as necessary.

Thanks again for all the help and direction.

Merry Christmas

67RAT
Dec 22nd, 04, 9:42 PM
yea,toss the accel plugs,they are CRAP!never seen a set work,never!! hadem,hatem.ac is the way to go,autolites are fine too,accel cost alot,and they suck! I know,they came with the car,but hey,sell em to a nieve e-bayer :D -67rat

Grape Ape
Feb 19th, 05, 1:27 AM
Hate to bring this old thread back to the top but I thought that some might like to read about the follow up.

Wolfplace was right ...even after changing the plugs, removing the spacer, and increasing the spark my baby was still having issues at low RPM. She idled poorley and had lack luster power off the line.

I have since removed the eldelbrock victor jr(single plane)manifold, excelent manifold for 3000 rpm's and up but caused issues at the low end, and replaced it with the Edelbrock Performer RPM (dual Plane).

Additionally I removed the the holley 750 double pumper with mechanical secondaries and a disabled manual choke (I belive to much carb for my moderately build 350 with auto trans) and replaced it with a holley street avenger 670 with electric choke and vacuum secondaries.

The difference was dramatic!!! More low end power, much better driveability, and quicker throttle response.

Once I came to the realization that "bigger is not always better" and matched my carb and manifold to my engine she runs, drives, and has more power than ever in the range that I use it....idle to 5000 rpm.

Thanks for the help, reality check, and istruction. Especially from Wolfplace.

ZZ69chevelle
Feb 19th, 05, 4:08 AM
Just curious, did you try the new carb on the Vic Jr. before swapping it out, or did you make both changes at once?

Grape Ape
Feb 19th, 05, 11:24 AM
ZZ69
I made both changes at once.

Mostly because I wanted a choke and better low end "driveability". Also because I believe the Double pumper and vic jr. were more of a race set up put on by the previous owner.

I can't decide whether to sell them or create some sort of display in my garage. (Both manifold and carb are in great shape).

God Bless

Pat Kelley
Feb 19th, 05, 1:54 PM
Sell them. That is a very desirable setup for a bracket car running in the 11's.

Wolfplace
Feb 19th, 05, 3:05 PM
Originally posted by Grape Ape:
Hate to bring this old thread back to the top but I thought that some might like to read about the follow up.

Wolfplace was right ...even after changing the plugs, removing the spacer, and increasing the spark my baby was still having issues at low RPM. She idled poorley and had lack luster power off the line.

I have since removed the eldelbrock victor jr(single plane)manifold, excelent manifold for 3000 rpm's and up but caused issues at the low end, and replaced it with the Edelbrock Performer RPM (dual Plane).

Additionally I removed the the holley 750 double pumper with mechanical secondaries and a disabled manual choke (I belive to much carb for my moderately build 350 with auto trans) and replaced it with a holley street avenger 670 with electric choke and vacuum secondaries.

The difference was dramatic!!! More low end power, much better driveability, and quicker throttle response.

Once I came to the realization that "bigger is not always better" and matched my carb and manifold to my engine she runs, drives, and has more power than ever in the range that I use it....idle to 5000 rpm.

Thanks for the help, reality check, and istruction. Especially from Wolfplace. =

Hi Shane,
Thanks for sharing & the kind words,, graemlins/beers.gif
Glad we could help & especially that it worked for you.
If you still have the spacer stick it on sometime & see if it makes a difference in your combo. Probably not but you never know til you try with spacers,,,

As Pat said, the Vic is an excellent intake for the right application which is mostly 4000 & up