To a degree, i agree. In this case who would recomend the cam that op has? I dont agree with the roller cam part of that statement. When a guy wants to build a 400, 500 and so on horse engine for the street, hes going to need a stall converter, might need deeper grears, and strokers are fun. But if hes not wanting to build power, he should rebuild stock. I was severly disapointed the first time i drove my stock l48 powered corvette as i figure you were, or your engine would be stock.

 

In order to develop more cylinder pressure (which is what creates torque) in your situation you need the intake valve to close earlier. By the intake valve closing earlier then more of the stroke of the piston is effective at compressing the intake charge. The air/fuel mixture in the cylinder cannot start to compress at low rpms until the intake valve is fully closed. Notice i said low rpms because the situation changes as rpms rise.
So if you have an intake valve that closes at say 70* after bottom dead center (ABDC) then the piston is already part way up the cylinder towards top dead center (TDC). That distance lets say is 2.75" when the intake vavle closes, of your total 3.48" of stroke on a 350. Now if advance the cam 4*and the intake vavle closes at 66* ABDC the intake valve will close earlier. This will increase the effective stroke of the piston on it's way up to TDC. So now you are compressing say 2.95" of the total 3.48" stroke of fuel/air. This is going to give you greater cylinder pressure due to more fuel and air being compressed and ignited. More cylinder pressure equals more torque.
Since all the valve events are on the same cam it also changes the rest of the events as well. One of note is the opening of the exhaust valve. Since the exhaust valve starts to open prior to TDC on the exhaust stroke by advancing the timing the exhaust valve will be open a little farther than before putting it in closer proximity to the piston near the TDC position. That may need to be checked if it was close before.
It is possible that some top end may be lost or the peak Hp may move down to 5000 rpms in your case or so by advancing the cam but in your situation I don't think you'll ever see it unless you plan on shifting above 5200 rpm all the time.
Advancing the cam would be the easiest cheapest attempt at recovering some low end torque.
Changing the torque converter to a higher stall would put you higher up in the rpm band when you start out and therefore you start moving when the engine is making greater torque.
I don't see where you have the trannie type listed but for a th350 or 400 the converter are going to be in the $200 to $350 range for a 2000 to 2400 stall converter.
The torque converter would probably be the next easiest solution, by itself you may still be unsatisfied but it would be better.
Torque converters also have a cool thing called torque multiplication. This means it take the torque of the motor and multiplies it to some degree. So the higher the rpms that the torque converter fully engages the more it multiplies the torque from the engine. Lets say it multiplies it 2.5 times over the delivered engine power.
So at 1200 rpm you engine may develop 200 ft/lbs of torque the converter makes that into 500 ft/lbs delivered to transmission.
So now at 2400 rpm your engine develops 300 ft/lbs and the torque converter delivers 750 ft/lbs to the transmission. 250 ft/lbs more torque to the transmission in only 1200 rpm. Here is an article about torque converters you may like to read.
http://www.ultimateconverter.com/article.html

Changing the cam to a different cam would change the power characteristics, but may not get you any more peak power and is probably the most labor intensive solution of the three.

 

I beleve the op has a manual transmission, original four speed anyhow.

 

Yes, I had to double check myself but he clearly stated he has 4 speed manual transmission.

 

Yes it is the original 4 speed. Keep the opinions coming.

 

all right I guess we can forget about all that torque converter business then.

 

Yes you said that long time ago.

If my memory has not failed your 79 had either a 2.43 close or a 2.64 wide trans.

Assuming you have a wide with the 3.36. 3.36 x 2.64 = 8.87
if you have 2.43 x 3.36 = 7.23 if i remember right manual cars came with a 3.70 with the L/82 close trans.

So if your at 2.64 x 3.36 = 8.87 very bad for a small engine car especially weighing roughly 3650 lbs.

3.70 X 2.64 = 9.76
3.90 x 2.64 = 10.29
4.11 x 2.64 = 10.85

I'm thinking your carrier could handle up to a 3.90 without being changed.

 

FWHP is Flywheel horsepower. Numbers are right.

 

79Vetter.....

You've had 4 1/2 years since this thread started to sort out your vette.
I'm curious as to what changes (if any) you've made, and weather these changes made a difference.
I'm also interested in knowing what you have for an exhaust....you said true duals/ no cats, but do you have stock manifolds, or headers, and how restrictive are your mufflers?
This seems to be a popular thread....how about some extra info

Oops...I see on post #53 you installed headers, and were disappointed and decided to leave it alone. With the setup you describe, it should run real nice up to about 4500 RPM with loads of torque and a nice smooth idle.
How about your harmonic balancer....maybe it has slipped and your timing isn't as it appears. You can get a good street replacement for $60, and it will come with timing marks on it. It's worth a look.

 

Right, depends on their intended use, I for one always ask for intended use, gearing, trans, budget and expectations. I don't race my car. There are a lot of C6 cars that are running 405-600 + HP that are not racing their cars. Some of these will go over 180 MPH. Do they need this much power and gears, no, They could drive a Prius. This is the tech and performance section. There are guys on here with 5-6-7-800 HP C3's that don't race their cars or run slicks. Thery do not want 300 HP, good vacuum and great fuel mileage. They want a nasty idle, They want it loud, to vibrate their fillings out and scare women and small children. They want it to take a while to warm up. They don't care if it is buzzing 3000 RPM down the interstate or if they do they are not putting a 3.08 gear in it they are leaving their 4.11 in it and putting in an overdrive trans. Like it or not these guys are the members here and there are a lot of us. BTW 300+ HP isn't enough for the OP. That is why this thread was started, He wants more power at launch, he wants it to throw him back in the seat. Lower gears will get him what he wants. A smaller cam might get him the same power and a lower operating RPM but not a real noticable difference.

 

He has a vortec headed 9 to 1 engine with a small cam. He isn't drag racing. He wants some bottom end acceleration without losing peak power. A bigger cam like your suggesting is going to kill the bottom end more. Your not hearing what he is saying. Similar power output to L82. They ran 3.70 gears. Gear it for the build. Outta here.

 

Very nice! That explains it so well. Changing the ring and pinion would cost less, but changing the transmission to a 5 speed with a low first would do about the same, but cost more. By mouses illustration, 3.90 looks to be the gear that would get ya the off idle feeling that your looking for. high way cruise and fuel economy would suffer. it comes down to cost versus intended use.

 

Nice! 2nd on that.

 

Regearing the rear is just one way to do it of course a nice five speed would be better but many people have limits on what they can really afford to do. But any point i'm trying to make he needs to get some gearing in the car.

You can't make a torque monster out of a 350 no matter what you do short of boost or other meassures non NA.

Many people think the newer engines although a little better are what makes them much stouter. Nope its 6 speed transmissions all kinds of gearing through the trans putting all that grunt in them.

For instance the C5 350cu. Z06, 2.95 low gear combined with 3.43 rear

3.43 x 2.95 = 10.11 low gear in a 3,150lb car

79vetter has 8.87 low gear and 500 lbs more weight to get rolling. If i'm wrong on his trans he has the 2.43 low close ratio trans with his 3.36 rear he has only 8.16 low gear.

 

Don't for get variable valve timing, it makes the best of both worlds. From what I've read, a simple cam change in my truck keeping with the vvt cam, I can gain 70 horse from a cam change alone. A lot of guy do the vvt delete, probably because also from what I've read the cam phaser is a pain in the *** to deal with, which equates to know nothing about and don't want to learn. I get ya on the 6 speed though, except in my truck with the max trailering package with 3.73 gears if you manual shift its next to impossible not to hit the rev limiter.

 

Yep, That's pretty much what I sugested. Only the diff rebuild is only $1,000 around here and the OP is wanting off the line giddy up and go. Maybe do a few burn outs. I don't remember there being a spending limit for the resolution. But he's certainly free to take your advice and not mine as you suggest.

I'll be in the weeds looking for more answers.

 

It doesn't cost that much if you pull the diff your self, provided your clutch packs are in good shape, you could probably change the ring and pinion yourself with the help of members like tracdog and probably several others.

 

It might be cheaper to put in steeper rear end gears, but a five speed with 3.37 first would be way more desirable.

 

I read the beginning of the thread, for U i suggest a 454.

 

ONE thing not covered is driver training.
if a guy with a stick lets the clutch out at 800 rpm, and complains it is not fast, he needs to go back to school.
A 350-385 HP 350 should throw you back in the seat around 2500, maybe even less. But not at 800. These cars are more tire limited, than power limited. Go to the OP's house. Are there black marks in the street? If not, there is the problem. Wimpy driving.