1986 iroc z28

So ill give some info first. I have a bone stock #3970010 engine. Ive got a victor jr intake, a demon #1282010 650cfm carburetor, And a cheap set of pacesetter headers. Before i put the engine in my car i would like to install a better camshaft. Its a new re-manufactured engine for a heavy duty truck and it came with a "torque" cam installed, but im guessing there are better options available.

So my main question for the professionals is what camshaft would be best for my application. Also im wondering if the carburetor might be to big. Ive heard rumors that a 500cfm would be better suited to this nearly stock engine. But i do have an afr gauge for it aswell so i suppose tuning it wouldnt be an issue.

GeneralDisorder

iTrader: (1)

The factory Q jet carbs are 750 CFM.

Is the engine a roller block or flat tappet?

GD

1986 iroc z28

factory flat tappet

GeneralDisorder

iTrader: (1)

You also need to watch the max lift the heads can handle, and what springs you run. But the Comp 268H is a perennial favorite:

http://www.compcams.com/v002/Pages/388/XE268H-10.aspx

GD

Ja85z28

The current Super Chevy has an interesting article showcasing the XE268H cam.

five7kid

iTrader: (14)

Heads. It's all about the heads. What heads does it have?

If they are the same heads that came on that old block, most likely they are better doorstops than something to go with a Victor Jr intake. Those heads flow so poorly they can't support a cam that makes power over 5000 rpm. Since the intake starts making power at 4000 rpm (3500 if you're feeling generous), you're building an engine with a very narrow powerband.

Can't make a usable cam recommendation without knowing what heads you've got. And what your intended use is for the car.

1986 iroc z28

sorry for the missing info. Im using a set of old style "double hump" heads. i know they arent very good, but its what i have currently. As far as intened use, its just a weekend cruiser. Car shows, and cruise nights.

sofakingdom

iTrader: (1)

Get a Comp "***** Thumpa". Drive the car show crowd wild, even if the car can't pull itself onto the trailer without the winch. The 8-yr-old kids don't understand.

five7kid

iTrader: (14)

Actually, not a bad idea. It will sound tough. As long as you don't try to prove it, you should be good to go. Get the lowest lift version (your heads & valve springs most likely can't handle much lift).

mrestrictrplate

iTrader: (2)

I can promise you, sell the vic jr, buy a performer rpm and the car will be faster and 10 times more responsive. A nearly stock motor with just a hotter cam with a vic jr will be a DOG!! you don't need the airgap rpm either, the regular one is fine.

Fast355

iTrader: (2)

I had a little 1980 L82 Covette. Bought it without the driveline. Ended up putting a Vic Jr and 500 cfm Edelbrock 4bbl on a flat top piston 305 with 059 Vortecs and a Crane 272H10 cam with 1.6 full roller rockers. With 1 3/4" long tube headers and pypes dual 2.5" exhaust with a X-pipe. That little 305 had powerglide with a 3,000 rpm stall and the stock 3.07 gears from the 1980 L82 Corvette. It cruised nice, had excellent street manners and had no problem in the go department. It ran 12.5 @ 112 mph in the 1/4 mile. I ran that car with the GM performance parts intake that came on the 330 HP 350 HO. The Vic Jr pulled so much better in the mid-upper rpm range. With only 2 gears and a loose stall I twisted the thing up to 6,500 rpm before shifting to high gear at over 90 mph to get the best times. One thing I did do that really helped the way the car ran was to build a plenum divider for the intake to make it more dual plane like. It did not hurt the top-end but made the low-end very dual plane like. It would sit and idle prefectly at 750 rpm with the a/c on and drive away with a light touch of throttle without hesitation or hiccup.

dmccain

iTrader: (2)

If your heads are stock type and cant take much lift the old trusty Summit K1102 flat tappet cam or something along those parameters is a good choice. 650 carb should be perfect and I agree on the performer rpm manifold