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Discussion Starter · #1 ·
I have a 79 camaro with a 355 in it but the engine just doesnt seem to have any power. i bought the car with the engine in it and was told it only had 300 miles on the engine. here are some of the engine specs i was given.
355,
4bolt main,
forged steel crank,
lunati 292 cam, 230 At .050, with a 480 lift.
TRW 10.1 forged pistons.
old 041 casting stock heads.
An edelbrock performer intake, (soon to be RPM air gap).
A demon 750 carburetor.
Headers
Turbo 400 trans (new clutches and pump) with a brand new
2400 B&M converter that will absolutely not stall any
whatsoever for some odd reason.

4.11 posi gears in the rear.


THe motor runs smooth (aside from cam lope), starts good, doesnt cut out or anything. Doesnt use oil. Revs high and quick, Good throttle response when idling, but it just doesnt seem to have any power, i mean, it will not spin a tire for nothin. I cant even get it to power stall, of course the brakes dont work just real great, but still, even turning, it just will not spin a tire. It just seems real sluggish. I have ordered some afr 180ccc heads, an air gap intake, and 1.6 roller rockers, will these make any difference? It just seems like it should have more power right now to me. I have a close to stock 350 it my truck and it will spin tires pretty good even with the 2.73 gears.
what could be the problem if there is one? thanks for any help
 

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The engine should run well with the combination of parts that are listed.

I do believe that your stall speed is too tight though for the big Lunati cam you've got. I would recommend a B&M Superholeshot or similar converter.

I would have to say that there are tuning issues to boot. Since you didn't put the engine together yourself, it's hard to tell if it's right or not.

I always remember a customer that built his own 454 and brought it to our shop to be dyoed. It barely made 400 horsepower, and for the equipment it had on it and the cubic inches, the guy was sorely disappointed.

We disassembled the engine, and found scored pistons and ill fitting parts.

A little detail work, a cam change and we gained 127 horsepower. Amazing!

I'm not saying that's your problem at all, but a 355 with the early 300 horse heads, 10.0:1 compression, a healthy lunati cam and 4.11s, it should run respectably. Start with the basics, make sure your timing in spot on, and check all the basic simple things.


2400 B&M converter that will absolutely not stall any
This has to be most of your problem. You don't have enough low speed torque with the big lunati cam. So either you put in a looser converter or put in a shorter cam.


Brian
 

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Lthompson,

You should be experiencing very good performance on your 355.

"041" – 3947041, also 3947041X. A good performance head. They were found on 1969-1970 302 and 350 engines. They had either 1.94/1.50" or 2.02/1.60" valves, 64CC combustion chambers, DO have accessory holes, I don't have port volume data for the regular 041, the 041X intake port should be 165CC's, the 041X exhaust port should be 65CC's. These heads have a single somewhat triangular shaped casting mark (slope on the upper left).

If you are not happy, as you have stated, take the car and have it dyno'ed. The initial set-up may not be correct. I would have initial timing between 10-12 degrees and 35 (or so) by 3000 rpm.
You didn't say what carb you had so, if it's between 600-650 it's
in the ball park. I think timing or jetting may be your problem.

It's only my opinion, and I been wrong (many times) in the past.

AngliaBob
 

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the last thing i would do is start spending money and throwing new parts at it hoping that will work.your set up should work very well.you should determine if you have a B&M hole shot or tork master though. the tork master is only good for 350 h.p..your converter will probaly not work well till fix engine problem.i start simple and do a compression test and check the timing.i always have to wonder when someone builds a motor like yours and sells it before they get a chance to beack it in.once your motor runs well the converter may not have much for stall but you shouldn't have any trouble using it.i have a 406 and had a tork master 2400 and it didn't stall much but work fine anyway and i have a cam as big as yours.start with the basic tests and i'm sure you'll find the problem.
 

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10-12 initial timing is way too slow to run good on and engine like that. I would shoot for around 20-22 initial. The easiest way to get this without having too much total would be to use manifold vacuum instead of ported if you are not already doing this. Breaking in the engine will not make much difference at all. Matter of fact, an engine is almost completely broken in after the cam break in procedure is done.

If your convertor is not flashing above 1500 RPM then I can see how the thing could feel like a dog. I had a very similiar 350 at one time with some wienerish 2400 or so convertor. It sucked! Went to a 10 inch TCI and was a different truck.

Chris
 

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i think you might want to rebuild the distributor or upgrade to an msd setup if it hasnt been done already. I had a completely dead distributor and we got it on the dyno it was only making 180rwhp and 250 ft pounds but there was all these jumps indicating spark problems. I was having the same problems as you not being able to spin the tires. I got an msd set up and went out for a litle test drive and when i first flooored it i thought i had broken the tranny because i was going 20 and the engine just started to rev but i looked backwards and there was smoke everywhere:pimp: . But luck have it it made so much more power i actually did blow the tranny out later that day:(
 

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I did not fully read all the replies so, excuse me if I rehash anytghing.

The cam is a little on the large side for the intake you have. The stall speed is also too low for the cam.

The intake manifold change should wake it up quite a bit and a little more stall ~3000 should get you moving well.

You have a good base but, you have some mis-matched parts (intake and stall). It is all about the combination of parts.

I have run that same cam in a 327 and it made plenty of power. The cam is not too big for your engine it just needs the parts to support it.

Royce
 

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Discussion Starter · #10 ·
Thanks for all the help guys, Torque converter is a holeshot 2400 that i recently purchased. One Question that i have is about the timing, . Thats one thing im kinda uneducated on. Is the initial timing referring to the cam or distributor, ive never actually checked either of the two. I just spin the distributor till it seems to start and run the best. How would i check to make sure the timing is all correct? The current distributor is a summit 50,000 volt HEI. Ive tried running the advance on both the manifold and the ported vaccuum. Couldnt really see a difference. Do you check initial timing with the advance unhooked? I just recently put a new demon 750 carb on it, i know thats a little bit big. But im waiting on my new AFR heads so i can put those on as well as 1.6.1 rockers and the rpm air gap intake. I just hate too get another torque converter because i already spent a bunch on having that one put in and te tranny rebuilt. But it just doesnt seem to have any stall, if i get a holeshot 3000 wil that put me at about a 2500 stall? Once again thanks for all the help

One other question i had was, when doing a compression test... at about what psi should each cylinder have for around 10.1 compression? thanks again
 

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Lthompson said:
Torque converter is a holeshot 2400 that i recently purchased.


Is the initial timing referring to the cam or distributor, ive never actually checked either of the two. I just spin the distributor till it seems to start and run the best. How would i check to make sure the timing is all correct?

Do you check initial timing with the advance unhooked?


I just recently put a new demon 750 carb on it, i know thats a little bit big. But im waiting on my new AFR heads so i can put those on as well as 1.6.1 rockers and the rpm air gap intake. I just hate too get another torque converter because i already spent a bunch on having that one put in and te tranny rebuilt. But it just doesnt seem to have any stall, if i get a holeshot 3000 wil that put me at about a 2500 stall?


One other question i had was, when doing a compression test... at about what psi should each cylinder have for around 10.1 compression?
First things first. Get a good timing light and some timing tape. Rotating the distributor may get the engine running but doesn't give you a clue as to where the timing actually is.

Not enough stall for the weight of your vehicle and the cam you are using.

Initial timing refers to the distributor timing and is checked and/or set at idle with the vacuum advance hose dis-connected and plugged.

If you are going to use the AFR heads, Air Gap intake and the Demon carb (all excellent pieces); you will definitely want to change the stall to a higher number.

Checking the psi with a compression testing gauge will give you the individual cylinder pressure. You want them to be within 10% from the lowest to the highest. The psi you see has very little to do with the 10-1 compression you expect because of the pistons you are running. Psi can be lower than expected due to cam lobe overlap.
 

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Technical Support Barry Grant
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The parts you have should work well together. You need to check you timing before making any changes at this point. If the timing is too low it will make the engine accelerate very poorly.
 
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