I feel like my car should be much faster than it is. To me it seems that i'm making a alot of noise and not pulling as hard as i should with my setup. Please tell me what you think about the combo:

350 bored .060 over stock crank, pink rods, & .0100 kb domed pistions

World Product S/R torquer heads (comperssion somewhere between 10:1-10:5)

comp cams xe268h .477 intake .480 exhaust duration @ .050 224int. 231exh. 110 lobe seperation 106 intake center line with 1.6 full roller rockers

edelbrock performer intake with 1 inch carb spacer

holley 650 double pumper (not tampered with)

hedman full length headers assuming 1 5/8, collector size unknown possible 2.5 inches, goes into 2.5 inch pipe to a magnaflow glasspack style mufflers dumped before the axle

th350 with b&m holeshot convertor 2,100 stall

The rear is a 3.73

I think that the car needs a bigger cam with more duration or a different gear. Now since i just finished up my project I've also been having a problem overheating and i'm pretty sure its because i'm running way to lean. Could just being off a couple of jet sizes sacrafice significant power loss? Now don't get me wrong the car is quick but it just seems that its not at its full potential. So is the gear too much or is something else mis matched with my set up. Thanks
-tom

 

I would check your timing and your carb first that what sound like the problem. And maybe should have went with a slightly higher stall. That motor should be able to throw down 350 hp

 

I have the timming set 12 degrees advanced, what should i check the carb for? the carb was new and unused before i put it on. Are you saying to check the jet sizes like i was saying perivously. Thanks for the response.
-tom

 

Whats your total timing at ? And yes check the jetting and power valve. Does the carb bog any ?

 

Here are my personal timing note Ive gotten from pro's and have served me well.


"Most V8's run best at WOT, with a total timing of 30-36*, all in at 2500 RPM, or less. The easiest way to determine your total advance is to use a dialback timing light. You simply connect the light, plug your vacuum advance, and have a second person slowly rev the engine. With the dial back feature, you adjust the light to keep the timing mark in sight as it rises. When the timing mark stops moving, you hold the RPM's steady, adjust the dial until the balancer mark lines up with the 0 on the timing tab, and read your total advance off the dial.

To do this with a conventional timing light, you need to make a 30* mark on your balancer. With a balancers of 6 3/4" in diameter. Circumference (360*) of a circle is pi(3.14) X diameter. 6.75 X 3.14 = 21.195"/12 = 1.76" (30*). Looking at the engine from the front, measure exactly 1 3/4" clockwise around the balancer, and make a second mark. This is your 30* mark. Connect up your timing light, and watch your 30* mark as you increase the RPM's. At some point, your 30* mark will stop rising, and move no higher. This is the RPM, where all of your mechanical advance is in.

SUBTRACI INITIAL DUMMY OF 10-12* [personal note as I always forget]

At this same RPM, with the distributor loose, adjust it so that your 30* mark lines up with the 0 on the timing tab. You now have 30* of total timing. Line it up with the 2, 32* total, ect.

Keep in mind that a stock distributor usually has stiff springs in it, that don't allow full advance in until 4000 RPM or more. For best performance, you want your advance in at 2500 RPM, or before. The easiest way to do this is to purchase a Crane adjustable vacuum advance kit. It comes with 3 sets of springs to allow your advance in as early as 1600 RPM, or as late as 3200 RPM, or anything in between. For points distributors (Jegs part # 270-99601-1,) (GM HEI, 270-99600-1). What I did was purchase the kit, and install the lightest springs(2 yellow). I used these springs to adjust my total timing, that way, I didn't have to rev the motor very high to see my total. Afterward, I installed the springs that brought my advance in at 2200 (2 silver)

One important note is to make sure the timing is returning to the initial setting, when the engine is idling. So when setting your timing, pay attention to when the advance starts, as well as when it is fully in. Having the distributor in the advance curve, at idle speeds, can cause excessive rpm drop with an automatic trans, with some camshaft/converter combinations. Generally, the more agressive a camshaft you use, the more important this will be. Advance curves should generally start at around 1000- 1200 rpm, when your idle speed is around 800 in Park.

"

 

To do this with a conventional timing light, you need to make a 30* mark on your balancer. With a balancers of 6 3/4" in diameter. Circumference (360*) of a circle is pi(3.14) X diameter. 6.75 X 3.14 = 21.195"/12 = 1.76" (30*). Looking at the engine from the front, measure exactly 1 3/4" clockwise around the balancer, and make a second mark. This is your 30* mark.

Why do divide it by 12? And once you look at the front of the engine are you measuring 1 3/4" from 0 or from a different mark? Do i have to reset my intial timming to zero or just get the marker on zero with my current timming? That part is a little confusing. Thanks
-tom

 

Trust him it works.

 

Not my math but I know its right cause it works, but don't ask me

you measure over 1 3/4 from 0 and make a mark, that 30*

you subtract the initial.

so if you have a 10 initial, at 20* you have 30* of total timing n so on......

 

When you get your timing sorted, you should be making peak power at 5500 rpm.
I wouldn't change the cam. The heads suck, and you won't believe how much better it'd feel with a 700R-4's lower first gear. Believe the words of experience, a 700R-4 with 3.73s is about right for a 350 that'll pull past 5500.

 

why do you have such a low stall?

3600+ stall is what you should have in there.

 

Gumby thanks for the info on the timming, and as far as the th350 I would defiently rather have a 700r4. I agree that it should also have a bigger stall but when i bought the car as a roller it came with the trans and torque convertor. Maybe if someone out there wants to trade their 700r4 with a nice stall for my th350 then i'll do a swap but as of now I can't dump anymore money into this car. Thanks everyone for the info.
-tom

 

I'm trying to do what you said but i still can't figure it out. First off am I pluging off my vaccum advance on the dizzy while setting the 30* mark? Next before i start to rev the engine to find the rpms were the 30* mark stops moving, do i set the timing at 0 to start? When I did set the 30* mark at 0 at the desired rpms my original mark on my balancer is way above 16* at idle, and idle speed is at 1,000-1,200 rpms.(my pointer only goes to 16*). Also i don't understand when i'm supposed to subtract my intial timing of 10-12*. If something seems off thats because i did all this with vaccum advance plugged on the dizzy. sorry just not completely understanding this
Thanks
-tom

 

OK long wait for a reply, needed to clear my head before I tried.

you always pull off n plug the advance when setting timing.

you don't set anything to 0, it just easier to watch the 30* mark you just made as its bold, what you want to do is note the RPM gauge to see when it stops moving, so you know the RPM your all in at. all you care about right then is the RPM things stop moving on the balancer.

You subrtact the initial from the total.

If you have an initial of 10, when you set the total to say 30*, you actualy only set it to 20, 20+10=30

Its not that confusing but yes it can be, takes me a while to get things staright.


What I do is first clean the balancer good, then spray the edge with white or yellow paint, make the 30* mark, then mark ever 1/4in with a smaller mark back to 0. So I can guesstimate better how far in between 30 I am.

There will be 7 marks from 0 to the 30* mark, so each 1/4in mark is about 4.3 degrees [30/7=4.2857142857142857142857142857143]

0 - - - - - - 30

so to try a total of 30, with a 10 initial, you set it near the 5th 1/4 in mark from 0, try it out, then bump it up a hair at a time till your happy.

Though member, you need to have the car at the RPM your all in at, when you set the total. don't try doing it at idle, why you want to know when your all in.

your still confused and so am I now but you just gotta do it a few times over

 

Gumby Thanks, i got it now after waiting for your response i figured it out but was still having a problem with my timing going back to were i intially set it at idle. It turned out to be that my idle was set to high so every time it went back to idle it was in the advance curve, but its good now, i apperciate the your time and knowledge you took help me out. Thanks again.
-tom

 

It can be a chore at times, always takes me a few tries to get things right.

 

holley 650 double pumper
you would be better off with a 3310 Holley (750 vac sec) carb

let the guys with 4 speed + sticks have the Double pumper cards.
and after all, the 650, is on the small side of CFM for your eng.
bet you get a better Take off with a rock stock 750 3310 Holly
and a lot more pull! from start to Finnish!

 

from what I am reading are you only running a 2.5 inch exhaust??

 

http://www.pontiacstreetperformance....p/exhaust.html

 

ArticwhiteZ i agree, i was going to bump up a couple of jet sizes and maybe put on 50cc accelerator pumps. Maybe i'll find someone who wants to trade or a good deal on a 750. But for now i can't afford to put more money in this car, i'm going to be getting started on my 78 boo soon. And yes my exhaust is 2.5".
-tom

 

a single 2.5 inch exhaust will kill the motor. A nice 3 inch would be much better

 

It has dual exhaust with dumps before the rearend.

 

Carburator CFM = (C.I.D x Max Engine RPM / 3456) x 0.85

 

ok i thought you had a 2.5 single exhaust