M20 rocker arms and valve adjustment

[zracer22]

I've been racing E30 325is cars for 4 seasons, and just recently broke a rocker arm for the first time. Nice clean break, and no other damage to the new motor. In fact, I was able to change it with out pulling the head. The rocker shaft slides right thru the cam gear. I have two questions. Is this common on the M20? The rocker certainly appears to be the weak spot. Does anyone have and tips or trick to advusting the valves?

[GKR_17]

Be very careful where you buy the rockers. I had a very similar problem on my 320i using cheaper aftermarket parts. Unfortunately, it took me a couple of times to figure out that the rocker would break first, then fall under the cam and snap it also. Never had the problem again when I switched back to OE BMW parts.

Grafton

[924Guy]

I'm not too familiar with racing cars with pushrods... but can you just use the old Chebbie trick of tighten till they stop making noise, then another 1/4 turn?

Of course, just 'cause it works for the old Suburban doesn't mean it'd be good enough for a real racecar...

------------------
Vaughan Scott
Detroit Region #280052
'79 924 #77 ITA/GTS1
www.vaughanscott.com

[GKR_17]

Originally posted by 924Guy:
I'm not too familiar with racing cars with pushrods...

No pushrods here, just rockers.

Adjust to the factory specs w/ a feeler guage and a small allen wrench, unless you want to buy the fancy cust BMW tool...

[Bruce Shafer]

What GKR_17 said. Always use OE BMW rockers bought at the dealer. I used these and never had a problem with my M20. I know others that had problems using aftermarket rockers.

Good luck.

[This message has been edited by Bruce Shafer (edited April 22, 2004).]

[mlytle]

joelg has had numerous issues with broken rockers. it is a relatively common m20 issue. my e30 m20 race car has run 4+ seasons with no problems though.

marshall

[JoelG]

I think it comes down to luck. There were 4 broken rockers (that I know of) at the bmw club race at vir last weekend, one in a an m20 and 3 in m10s.

none of them were mine for a change

[Dave Ebersole]

There is usually a relationship between broken rockers and and a tach telltale needle, especially with aftermarket rockers. Get the rockers with the roundel on them.
Dave Ebersole
O=00=O