I am working of a friends 350 in a Nova. The motor is a basically fresh rebuild stock 350 with a cam, carb, and intake. The problem is the cam is much too large for the rest of the combination. We are planning to install a smaller cam to boost the low end torque and increase the driveability. However one of the key factors for the owner is the sound of the car. The current cam has a strong lope at idle and a good rap at WOT. He would stongly like to keep a similar sound to the car. Even if it sacrifices driveability to a point, since anything will be better than the current cam. My question is can we alter the timing events of the cam to increase the lope of the cam while decreasing the total duration of the cam? For example tightening the lobe centerline.

Here are the current specs for the motor.

350 +.030"
KB120 Flat top pistons
8.9:1 CR
Mildly ported Chevy 441 heads w/1.94"I and 1.50"E
Elgin E920P-292 single pattern hydraulic cam
.480" lift / 292 degrees adv. 109 degree LC
Performer Intake
600 Holley Vac. secondary.
Hooker 1 5/8" Headers.

I am looking a something similar to a Comp XE274H cam. This has 274 intake and 286 exhaust with a 110LC. I am assuming that this cam will have a noticablely smoother idle. If we tightened up the LC to 108 or 106, would this affect the idle quality.

Any thoughts or suggestions?

Thanks.

Not too familiar with small blocks and duration needed, but yes, going with a tighter LSA will make a more aggressive idle, at the expense of a narrower power curve...probably not a noticeable thing if it's not strictly a race car...it will also increase the cylinder pressure a little, all other things being equal, so be careful with that (detonation). I have never gone with anything tighter than 108, so I cant give an opinion, but the 108 LSA I had with a duration of 248 or 252 at .050, in a big block, sounded super. John

Bet that little Crane Energizer 274H06 would sound neat in a near stock compression motor. Wish I knew someone who had run one.

The XE274 cam will be way big for the compression ratio you are running, in fact I bet it is comparable to the elgin cam in the higher rpms powerwise. The xe268 would be a better choice I'd bet, and it does have a good sounding idle at 700-800rpms.

Thanks Guys.

Gene, I like the looks of that one. I played with it a little bit in Desktop Dyno and the Crane picked up a buch of low end from the Elgin. :D

Now the guy is talking about a set of Vortecs to go with the cam. That seems to really wake up the Crane.

Thanks.

So,I bet this car has some highway gears and a stock torque convertor too,which would contribue to some lazy performance.
The Elgin grind is the same as the old Crane 302H Fireball..think its ground on a 114 or 112

I'd keep it as it is cam wise and change heads to vortechs. Don't have to risk a flat cam on break in and also won't have to drop the oil pan. You will have more comp and higher flow velocity heads too, sure you need an intake but worth it imo.

Chris,

It is actually on a 109 CL. I did get him to change the converter last year. It isn't loose enough, but it is better than stock. The rear is a 3.55. Not great, but fair.

This thing is really a pig in the low end. It barely idles and it pulls about 6 in. of vacuum at idle. This car will never see enough RPM to see the light of day of this cam.

i'd go with some smaller chamber heads and keep the cam. withathat cam, i,d look 4 a c.r. of around 9.8. tighter lsa = rougher idle' wider lsa = smoother idle.