Z/28 302 camshaft selection

[SSRSBOB]

CHP likes the Comp Cam 30-30. That is what we will use.......maybe. Also has another that we are thinking about using close to the 140. Engine he built with this cam made like 420-425 HP. Very stoudt.

Still won't give me HP numbers on that wheel standing stocker of his.

Bob

[Salvatore]

You can probably figure the hp of his car pretty close by how fast, the car weight and so forth. He is running in D/Stock. Hopefully Pomona will be nice and cool and he will run a 10.50, maybe even in the high 40's. Don't worry about dyno numbers, worry about how fast you go and all the BB's you beat!

[markjohnson]

I've always heard that the #140 Off-Road Camshaft was just what it's name implies and that the stock Street Z/28 (#178) was much better for a street car. Chevrolet's 60's era musclecar camshafts were notorious for lots of duration, especially that #140 Off-Road Cam. As it's name implies, it's geared towards lightened Trans Am-style race cars that spend ALL of their time at high RPM zipping through corners and blasting down straightaways. Those small cubic inch 302's aren't known for having loads of torque anyway. If you've ever driven a four speed street car with a massive duration camshaft, it's really not a lot of fun and at least 4.11's in the rear axle is an absolute must to try to compensate for it. My vote is for the stock #178 Z/28 camshaft.

[SSRSBOB]

Mark,

We have the 178 cam in the engine that I sent to CHP. Car was a turd with it. 3.73 gear and M21. We will change that. From what I was told by CHP and others who know the 302 better than anyone is that this engine needs gearing for it to perform like a performance car. Camshafts will not give this engine more torque.

One of my best buddies bought a brand new 68 Z8. 3.73 and M21. He sold it less than a year later because he was very disappointed in the performance. Back then, D. Harrell told him that these engines need gearing too. Doing that awakes a sleeping giant.

Bob

[BUIZILLA]

the 140 cam must have 4.56 or better gears, most likely a 4.88/5/13 works the best..
302/3.73/M21 is a dog.... 4.10's and M20 is MUCH happier street driving, 4.56/M21 for drags

[SSRSBOB]

Mac Neish has a local Camaro Z28 customer with 4.10, M20 and 140 cam that runs in the low 13's at 108 on street tires and closed exhaust. That is our goal. I am going to call this customer and ask him directly too.

Bob

[markjohnson]

A wide-ratio Muncie with the 2.5 First Gear is an immense help towards getting those 302's rolling from a dead stop. What they lack in low-RPM torque needs to be compensated for by gear-multiplication.