now maybe its me....and i've been driving fast cars for the past 15 years...Porsches and Ferrari's.....and i just sold my Mitsubishi EVO 8 with 400HP.....but my 396 with headers, mild cam, 4spd, Mallory dist, Edelbrock carb and manifold..3:73s gear.....just isn't fast.....i just purchased a Holley 770 Steet Avenger...but i haven't put it on yet.....even a guy that builds classic cars drove it one day said it seemed weak...it doesn't blow any smoke or burn oil...it runs great and starts up perfect everytime...is it me?....i was thinking of finding a dyno and start there....any suggestions?....i mean the car should have at least 375hp with all those mods correct?

what is your timing set at?...Thats probably the issue.. I have had a stock 396 with a Crower solid cam run mid 12's

well i checked it the other day and it was at 12 degrees....it says in the manual its supposed to be at 4 degrees.....i was reading an online article that said i should put a timing tape on the harmonic balancer and have it at 36 degrees at 3500 rpm....i just haven't been able to tackle that yet

I tell you what, compairing supercars against muscle cars can be alarming. My dads new corvette (LS3 6-speed) will hold its' own or just flat out out run most of the 60's and 70's factory muscle cars.
Just remember that a 396 was designed and produced in the early to mid 60's. It will not, in factory form, outperform a modern 400hp supercar.
Just my opinion,
Smitty

well i checked it the other day and it was at 12 degrees....it says in the manual its supposed to be at 4 degrees.....i was reading an online article that said i should put a timing belt on the harmonic balancer and have it at 36 degrees at 3500 rpm....i just haven't been able to tackle that yet

those are the stock timing specs for a stock cam. You want 36-38* total by 3000 rpm

I "assume" you mean timing tape on the balancer and not a belt :D ;)

i don't expect it to outperform any of those cars.....it just seems slow....my 06 Tundra will probably blow my Chevelle's doors off....but then again that truck is pretty fast.....maybe my expectations are high....i dunno....once the secondary's kick in on the carb it does take off....but off the line 1st and 2nd and 3rd...dogish...maybe its the gears....maybe i'll have to let someone drive it that knows more about these engines

the car is probably as fast as any thing you've ever had, it just doesn't "feel" as fast because it doesn't zing past 7000 rpm before each shift.
you need to get some hard numbers- go to a dragstrip on a "grudge night" or test and tune day and see what it does.

Yeah, sounds like either a poor tune and something isn't right in the fuel system/carb, or you just have a bad combination of parts and have an oversized cam for your compression or something along those lines, who knows.

Anymore details on the parts you have would be great. First things i would check out though is your carb, that new one might fix some of your problems.

Daniel

This may sound stupid- and I subscribe to the theory that there are no stupid questions-but have you checked and double checked the throttle and secondaries? My brother's 81 TA w/ a 455 seemed slow too (compared to my 383 chevelle) but after checking and rechecking- thinking we had it nailed- he just wasn't getting full throttle. And after adjusting the line, he needed to adjust the vacumm spring so his secondaries truly opened when he needed it and fully.

Maybe it's something simple.

I also think that these are muscle cars and we do beat on them from time to time. Things break, wear out, etc. It's a good idea/practice to check things routinely. I just found that my dist's mechanical advance failed- had no clue. And only after just on a hunch timing it for first time this summer.

Weak torque converter?!?

well i ordered a Holley 770....i'll put that on and see how it feels....how quickly are the secondaries suppose to open on an Edelbrock carb?...i'm not sure what size it is...but it looks pretty new.....i know they open in 4th gear when i have it floored....i felt them kick in...but only when i floored it.....i'm pretty sure....i just finally got the brake to hook up so i too scared to go fast in it till now....

well i checked the carb.....its a 750 cfm Edelbrock....looks pretty new....i'm going to check to see if i'm getting full throttle tomorrow....it says on the website that the secondaries are supposed to open up around 65%

Hows the gearing?

Dont set timing for totl only as that usually leaves the base timing retartded which is part of the problem along with maybe the secondaries in the carb not opening all the way too.

Your base timing is retarded at 12 deg with a perf cam,you need at least 18 deg base timing and 36-38 total for your 396 bbc.

Set the timing at 18 deg base with idle low like 600rpms to ensure mech adv isnt partially avtivated upsetting base timing adj,vac adv also needs to be unhooked/plugged when setting /checking base/total timing.

Then you need approx 18-20 deg mech adv in the dist all in by 2800rpm so 18 base timing + 18-20 mech = 36-38 total in by 2800 rpm which should wake up the motor some esp comming off idle and when in lower rpms below when the full total is in due to running an additional 8 deg base timing which is substantial.

If the total is over 38 deg at 3k rpm or above with 18 deg base timing you will then have get the mech adv in dist recurved for 18-20 deg max at 3k rpm to work with the 18 deg basetiming your motor needs with a perf cam,stock GM cams use the 4-6 deg you mentioned but not any aftermarket perf cam,they new 3x-4x more timing then most stock gm cams do back in the day.

For street you should also run a vac adv hooked to full intake vacuum all the time too foe better idle with erf cam/better fuel mileage/crisper feeling motor & throttle responce/and cooler running motor n traffic.

Not you need to also insure the secondaries in the carb (esp vac sec)are opening up all the
way by roughly 3,500rpms with your 373 gear .

With moroe timing and getting the secondaries to open up at fully at 3,500 or so rpm that should HOPEFULLY wake up your 396 some more.

Let us know how you ig goes with the tuning/dialing in of timing and secondaries on carb.

Run 93 fuel with this street perf ign curve and listen for ping esp if total ends up at 38 along with running running vac adv.

Timing!When I first got my LS-5 it ran ok,but I thought like you,it should do better.The mechanic at the local speed shop said I should take the distributor out and let him set it up,as a lot of the time they're set up wrong.He did mine and said whoever had monkeyed with the advance had really screwed it up.Installed it at 3k@38 allin,and it was like night and day.Will now run low 12's,with me granny shifting the 4 spd in street trim.Get your timing set up right before you do anything,cheap and easy.:thumbsup:

Not you need to also insure the secondaries in the carb (esp vac sec)are opening up all the
way by roughly 3,500rpms with your 373 gear .

With moroe timing and getting the secondaries to open up at fully at 3,500 or so rpm that should HOPEFULLY wake up your 396 some more.



Getting the Edelbrock secondary air valve wide open by 3500 rpm is going to take some serious grinding on the counterweights. Even switching to a Holley VS carb won't improve the situation, as the light spring doesn't allow the secondaries to fully open until about 4900 rpm.

Hi Mike, your Looking To bust Chops Aren't You(lol!!!) ,HMMMM, its funny you find the time to bust chops but spend absolutely zero time trying to do something positive in helping this guy out,doesnt look good.

If i remeber correctly You have kinda come at me like this before,i guess my long winded explination's rub your feathers the wrong way(sorry about that) . It seem's like your just looking for a chance to pounce and you thouhgt you had a chance this time & did so.

Yes i do at times disagree with others here but i try to do it repsecfully and then go on to explain why i disagree and what might help the situation out,not just throw stones & then offer nothing/nada in return that you think might help out.

YES i Missed The Fact He An Eddy which you were correct about. But i Did Mention if its "Vac Sec Carb to try to get the sec opening by 3,500 or so with 373 gear" with his setup for best perf which is possible with vac sec holley like the 3110 . I Would Never Suggest (and didnt suggest at all) for Anyone to Grind The Weights Off The Sec Linkage like you were getting at even on an Eddy carb to do that.

Also,BTW, i believe you can get a holley vac sec carb to open fully before the 4,900 rpm you stated they will be fully open at,guys do it all the time here in t/chevelle with proper tuning /tricks esp on 3110's .

Scott

i'll need a timing tape to do this correct?...or maybe i should find a speed shop to set it up for me.....anybody know any good speed shops in So Cal???

You don't need a timing tape, just make a mark 36° BTDC on your balancer. 36° is 1/10 the circumference of the balancer. If you want an 18° mark, make one halfway between your 36° mark and TDC.

I'm not trying to bust anybody's chops, I'm just posting what I think. Since you didn't explain how he was supposed to modify his carb to get the secondaries open wide at 3500 rpm, I'd like to hear from some guys who have modified their 3310's to open fully at 3500 rpm, how they did it and how they measured it. It's quite a trick to sit on the fender of a car looking at an engine under full load at 3500 rpm and watch the secondaries opening. Most of the ones I've watched don't open until around 5000 rpm with the very lightest spring.

so i would mark on my harmonic balancer 1/10 or 36 degrees above the line....then how would that line up when i use the timing light?....am i being stupid?

A brand new Hemi Cuda right off the dealer's Lot was a massive Pig! What do you think this car did once the cam was changed,headers added,and the Carbs tweaked? Do you think it was still a Pig? I hope you don't think so!

The point being that the Supercars of today are, reasonably speaking, maxed out performance wise. The Muscle Cars of yesterday were intentionally de-tuned off the Showroom floor for a variety of reasons.

The 396 in question probably needs a little cam to make use of the big ports and some timing.

I'd like to hear from some guys who have modified their 3310's to open fully at 3500 rpm, how they did it and how they measured it. It's quite a trick to sit on the fender of a car looking at an engine under full load at 3500 rpm and watch the secondaries opening.

i use a paper clip to determine vac secondary throttle angle at wot.Attach the clip to the link between the diaphragm housing and throttle shaft.The clip should slide on the link up to the bottom of the housing freely.
Drive the car at wot and then shut off.The paper clip will be fixed on the link at whatever angle the sec blades opened to.You can simply roll open the secondarys until the paper clip contacts the housing and then view the throttle blades and determine their position at wot/max rpm

so i would mark on my harmonic balancer 1/10 or 36 degrees above the line....then how would that line up when i use the timing light?....am i being stupid?

The 36º mark will line up with the zero mark on the tab once the timing reaches 36º. To set total at 36º, rev the engine until the timing stops advancing and then turn the distributor until the 36º mark aligns with the 0º mark on the tab.

well changing the carb to the Holley 770 woke the car right up....i now can light up the tires.....strange...the Edelbrock was a 750.....i'm going to put it on my buddies dyno tomorrow so i'll keep ya posted with HP numbers......its fun now:hurray::hurray::hurray:....i even put the screw in my secondaries so they all open up at the same time(a trick we used to do when we were younger when we wanted instant power)....fun fun

Timing tape the best $4 and 4 minutes you can spend on your car.
http://store.summitracing.com/partdetail.asp?part=SUM%2D162591&autoview=sku

i ordered one yesterday....when i put it on..... do i line up 0 on the tape up with the line on the harmonic balancer and then just when i start it up with a timing light i line up 36 degrees with the 0 on the tab at 3000rpm?

Yes you can do that. The most accurate way is to find top dead center but that's a little more complicated.

When you check the timing you want to bring the RPMs up slow and watch the timing advance. It should stop advancing at 3000 RPM. If it continues to advance after 3000 you need to recurve the distibutor so (all your timing is in by 3000RPM)

i checked it the other day and at idle it was at 14 degrees at 800 rpms ....when i got it up to 3K rpm it was just way past the tab by 1 in or so....but it did stop moving at 3000 rpm....does that make sense?

Yea that sounds right. Check this out.http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Distributors/85551_instructions.pdf

i tried a timing tape once- it worked great until it decided to spontaneously fly off when i was checking the timing.
i went to Sears and bought a dial back timing light- no need for any silly tape and you only need to line up the mark on the balancer with the "zero" mark on the pointer.
yes- it does cost more than a timing tape, but trust me- you will use it enough to make it a worthwhile investment.

Wash the damper with thinner and give it a little clear coat...problem solved.

My timing tape has been on the ballencer since 2001 when i rblt it ,5k miles later,but i do have a dial back light too.

Scott

I put the timing tape on then spray clear lacquer over it. Seems to help keep it in place. I bought a car one time and the carb had the screw trick in the secondary arm slot. First time I put it to the floor, the secondaries got pulled over centre and stuck wide open. Luckily I got the car shut down before anything happened. Be careful with these little add ons.