Just received a 350/290 HP Crate motor to put in my 39 Chevy from Chevy Parts. Found out that the cam was installed retarded 1 degree. Decided to advance the cam +4 degrees for better performance. What can I expect from the engine and what should I set timing to? I'm running an Air Gap manifold with one 590 Holley Street Avanger Carb.
Advancing the cam moves the power band to lower RPM. A 5 degree change from factory specs is quite a jump without running the engine first to see if it was needed.
Advancing cam helps power at the lower end of a run. Retarding a cam is for top end power. Moving it 5 degrees all at once is quite a change, unless maybe your going to run the 100' drags. Pat
I think unless your bracket racing and wanting to pick up your power band from low or high. I would install the cam dot to dot. If the cam has any kind of bump to it, run a little stall converter. The converter will allow you to pull alittle easier from a dead stop, take out any flat spots the carb might have when mashing the throttle. Just my 2 cents!
Making that kind of change is a big timing change and quite frankly won't make much difference on a bone stock motor. The purpose of cam advance is trying to fill the combustion chamber more effeciently. What you need to be sure of is valve to piston clearance. Happy motoring !
I purchased the same motor for my '32 Ford 5 window coupe. While I haven't turned it over yet, the time is getting close. I'm running an OFFY 4X2 intake, with 4 Rochester 2GV 2bbl carbs. Several guys have asked if I am going to have "enough cam" in this motor, but the guys at Summit Racing Equip. tech department said 't "shouldn't be an issue?" I'd be interested to know what you run into with your motor & adjustments. Please keep us posted & I'll do the same. Thanks!
As said before don't make such a big adjustment all at once, and Yes advancing the cam will do more for the low end.
Realize that Chevy delivers the engine 1 degree retarded, and all I did is advance it so it showed 3 degrees on the wheel. Looking for more bottom end to get 3800 lb 4 door moving.
Maybe an Airgap intake is not what you want in a heavy car.Lot of talk about those a Chevy Performance site.Seems they can have some driveability issues at lower speeds due to poor fuel vaporization.
Old Buckeroo lives in S.C., where it's warm a lot. That really helps with the air gap manifold issues with no manifold heat. Plus, he wisely chose an appropriate size carb so it'll have good air velocity which really helps with atomization issues. It's really not much different than a regular manifold with the exhaust crossover blocked.
Just out of curiousity how did you determine the cam was retarded? Did the crate motor come with a cam card?
I have this motor in my elcamino and its is the biggest pig i ever owned. It doesnt make any low end power. Ran a performer intake, 600 holley, headers and a 2000 stall with 3.42 gears. It doesnt make any power until around 3000 rpms and poops out at 5100. My stock S10 blazer with a 4.3 runs circles around. Hope u have better luck.
That sounds like a reasonable combo. Curve the distributor. Try and get 15-18 degrees initial and around 38 total. As far as the original poster......I would've left the cam timing alone. These aren't performance motors. Also, I'll bet that intake manifold is too big for one of those anemic 290 HP 350's. I'd run an old SP2P that everyone hated for power. But, they sure are responsive down low
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