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View Full Version : Z/28 302 camshaft selection


Lynn
01-21-2010, 04:20 AM
Building two 302's and want them to be as authentic as I can. Even have "0" rockers.

I have one original camshaft, but it needs to be reground. Would rather start with new. Tried to purchase the blueprinted versions sold through GM, but apparently Crane no longer makes them (I know, out of business, back in business, but seems to be focused on bikes).

Rep at the GM store says he can get me a Sealed Power replacement. Anyone have any experience with these?
http://www.power-21.com/federalmogulpower21i/PartDetailWindow.aspx?b=SD&pt=Camshafts - Speed-Pro&pn=CS118R&pb=SPEED-PRO

If that isn't a good choice, what other options?

Thanks in advance.

rafbody
01-21-2010, 04:54 AM
http://www.camaros.org/forum/index.php?topic=6226.0

Lynn
01-21-2010, 04:58 AM
Thanks.

Nova Jed
01-21-2010, 05:00 AM
What were the 302's originally rated at? 290 hp?

Plowman
01-21-2010, 05:14 AM
But they had 350 hp.

SSRSBOB
01-21-2010, 05:25 AM
You need to talk with CHP. JM is the man with the 302. We sent our 302 to him and he gets stoudt numbers out of them and they run on pump gas and built the way the factory built them. Ken Veit has some of his stuff at CHP too. That should make a statement. Watch the Mcneich You tube video in the pit section here. One guy posted he walks the walk and talks the talk. Thanks to SYC for getting me and my boys hooked up with someone we can trust.

Good luck,

Bob

Nova Jed
01-21-2010, 05:36 AM
That's good to know. I have the heart and sole for a 302.

RamAirDave
01-21-2010, 06:35 AM
Hey Lynn,

The two Zs we built were both -140 cams. One NOS, the other a "new" cam. No issues with either. Have a Comp 3030 in the box here at the shop.

Don't know which brand the "new" cam was, but can find out if you want.

SSRSBOB
01-21-2010, 06:44 AM
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
01-21-2010, 07:57 AM
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! http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif

markjohnson
01-21-2010, 08:46 AM
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
01-21-2010, 04:08 PM
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
01-21-2010, 05:45 PM
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
01-22-2010, 07:31 AM
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
01-22-2010, 10:38 AM
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.

drdave69
01-22-2010, 02:57 PM
I concur with the opinion on gearing and the right transmission. My old Z/28 had the stock replacement cam with M20 and original 4:10 rear. It performed pretty well (except on the freeway). http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif

Hotrodpaul
01-22-2010, 04:10 PM
I wonder what the little 302 with a street friendly solid roller cam, modern tremec 5 speed with low first gear, and some 4.10's out back would be like? A similar situation exists with the Mustang Cobra's 4.6L 4 valve engine that has little bottom end but loves to rev. I had a 98 model with T45 trans and 4.10's and the car was a blast! That low first gear (3.37 I believe) with the 4.10's gave great torque multiplication with the overdrive (.67) dropping the cruising revs on the freeway. This would be a great tranny for a swap into a non concours first gen Camaro.

Paul

Lynn
01-22-2010, 08:55 PM
Thanks for the offer Dave. I went ahead and ordered two of the comp cams.

I have run a 140 cam with a single four barrel, and it absolutely screamed from 6000 to 8000. I didn't find the idle that objectionable. Kept it set at about 1,000 warm.

Salvatore
01-22-2010, 10:47 PM
Most people work on the wrong end of the car when talking about a sb Chevy, especially the 300 inch motors. I like the 4.56 and the M20 for the Z/28's. Keep the hood closed and jack the rear up. http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif