Hey all. I'm back again this time I was wondering if I could get specs on Lobe Center, Lift, and Duration. What would be the largest Cam I could put into an 80's model 350(Carb) on all stock components without pinching springs etc. I don't have nor can I get the head castings or such just a general approximation would work. Thanks for the help guys.

Cristian(aka Thermaltrans)

 

Well no new aftermarket cam should be installed with stock valvetrain components. Ive never seen a manufacture that didnt void the warranty by useing stock stuff or should i say original stuff. Alot of things can use NEW stock springs as long as there new. However if you neeed new springs anyways you can get a huge cam with direct rep[lacement aftermarket springs. A cam far larger than what is required for your average motor.

 

Typically a stock replacement camshaft peaks around .480 lift. Factory valve train is really pushing it when you get close to .500 lift. There are so many clearances that need to be checked when doing a proper cam swap.

The most obvious is piston to valve clearance but there's many others. Using stamped steel rockers, too much lift can cause the rocker to bind against the rocker stud. Too much lift can cause factory springs to bind. Too much lift can cause the underside of the spring retainer to hit the top of the valve guide/seal.
Too aggressive a ramp with a long duration but with a short lift can hammer out valve springs quickly.

When using factory style heads, keep the cam upgrades to just a little more than factory specs. Cam manufactures will usually state if the cam will work with a stock valvetrain or not. Which cam to use depends on what you intend to do with the engine.

 

It's my friend. He was hoping to get around the largest he can get and keep the engine running with no problems until he gets the time to build the rest of it. He was just wondering roughly the specs that could be used without harming the stock components. He has experience he was just hoping someone could help him with figuring this out.

So you're saying that around .480 lift cam would be the max recommended for the stock components? What about the Lobe Center and Duration? Will they be more or less set(I've never replaced a cam before he asked for all 3) by the amount of lift?

 

The Crane Compucam 2032 is the largest cam I've seen for stock heads. And its still recommended to get new springs so you're not using the stock 20+ year old stuff.

 

If you are just looking to stuff a big cam in it to show off, use a Isky oval "lift rule cam"

eg Isky Mega278 or Mega288 pn 201278 or pn201288
www.iskycams.com. Look up the specs for yourself.
The modest .450" valve lift is not going to cause any clearance or coil bind issues. Both have tons of duration and overlap to give the desired effect.
Degree in advanced on a 100 to 102 intake C/L for best power in a stockish motor.
Isky drop on stock high perf replacement springs #205D are recommended for high rpm.
Stock springs are going to float around 5000 5500rpm.
Both cams like increased compression ratio, lots of rear gear ratio and a 3000+ high stall torque converter and a agressive distributor advance curve.
Both have the "bad boy street racer" idle.

 

I would just put an rv cam, some 1.6 roller tip rockers and some z28 springs

cheap nice ponies

 

Hi, I'm new here, and was wondering whats a good cam to get for a 1991 camaro RS. It has a completely stock 5.0. about 135,xxx miles. I should change out the springs too? Is there anything else that should be replaced? And what type of advantages does changing the cam give?
Thanks.

 

hopefully after you are done when you hit the gas the car tends to scare you a bit untill you get used to it