bhagg

I have rebuilt and swapped cams in my 90 IROC a couple of times (factory roller cam), and there is plate that screws to the front of the engine to keep the cam from walking in and out of the block.

Now I am building up a non roller cam engine (’84 and prior block), and can’t find in any of my shop manuals any sort of piece that does the same thing in these earlier engines. In addition, the face of the cam doesn’t have a grove around it that would make it work with such a plate. What keeps the cam from walking in these engines? It seems to me that the timing chain will end up rubbing against the face of the engine or the inside of the timing chain cover. There’s little movement now, because the chain is new and tight, but what happens after 60,000 miles and I get some slop in it? Is there a part here that I’m missing and need to get?

Thanks, Bill

Engineboy

No pieces missing. The timing chain is the only thing that keeps the cam in there.

Flat tappet cam lobes are actually cut at an angle (ever so slight) so that the lifters rotate while running. I believe this angle helps keep the cam in there also.



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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

GO #3

jcb999

bing-bing-bing. Good answer. I was going to send you a virtual beer from http://www.shiner.com/vrtbeer.html but you can't put it on the web only e-mail.

You are old enough to have a virtual beer right?

five7kid

iTrader: (14)

The above answer is correct, and the distributor drive also contributes.

Get a cam button to add to the older engine. The best kind has a roller thrust setup, but a plain bronze button will work for a non-roller cam as well. They just bump up against the timing cover to keep the cam back where it belongs. It's good insurance. A "block saver" bearing between the cam gear and block is a good idea as well. I have both (bronze button, roller thrust bearing block saver) in the 396.

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82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

Engineboy

Jcb999:

Yes, don't let the name fool ya, I've been drinking (legally) for 12 years.....hmmm.....I feel old now.....but thanks for the beer!!

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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

GO #3

GOLD85

all corect, but also the lifter keep the cam from walking. the lobes are not perfectly level, thay have a slight angel on tham

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when the green flag drops the bull$hit stops

350,performer RPM intake ,650dp, 700r4, headers, 3inch exhast

Engineboy

Didn't I just say that?? :

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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

GO #3

Red Devil

Actually EB, you said the cam has the taper cut. Which is correct. The lifters themselves are convex, not taper cut as he stated. This is how the cam stays in and the lifters rotate all at the same time.

Engineboy

I missunderstood him, I thought he said the same thing I did.

Thanks

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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

GO #3

[This message has been edited by Engineboy (edited October 22, 2000).]