Hello everybody, My name is Paul, I am from ohio. I have a 1980 cutlass 2dr that has been in the family for a long time. It has a 68' olds 350 rocket engine installed in it. My concerns are the valve traine noises i am hearing. It has the jm 20-22 camshaft/lifters i purchased through mondellos. And i purchased a set of scorpion full roller stud mount rocker arms from summit racing...I have adjusted the valves several time, and i still have chatter.. mostly when acceleration..I have the correct length pushrods installed along with a set of elderbrock valve springs. I've done my homework and everything should work together....I do have guide plates installed also..Should my rockers move side to side on the valve even with the guideplates? Any help would be appreciated..Thank You...

 

Hi and welcome to CO.

Make sure you are not running a 3/8" guide plate with a 5/16" pushrod. Roller tip movement side to side on the valve stem should be minimal.
I have heard some noisy cams in the past..fast ramps will do that, not sure if that's the problem with the 20-22. Look for interference elsewhere, such as pushrod to Head, or inside of Rocker Arm to Valve Spring retainer...just some thoughts.

Danny

 

Hi Danny, Thanks for the idea's...I just Pulled 2 of the rockers off and looked for any interference and it shows no signs of anything hitting. Also double checked my guide plates and they are for the 5/16" pushrod...And as far as the pushrod hitting the head..That shouldnt be a problem considering my heads have been drilled out to accept a 3/8" pushrod....So if you can think of anything else, Feel free to let me know.....also i have adjusted these valves several diffrent ways.according to videos on youtube...So any advice on adjusting them may be helpfull as well...Thank You

 

Week lifters. If the cam and lifters came from "Mondello's" of Paso robles CA.
They are probably Chinese made. Which have poor valving in them.

Gene

 

You're pretty much right. However technically it's not the valving per se, but actually a poor fit between the inner body of the lifter and the plunger itself. That lends itself to bleed off easily and therefore be noisy.

Also, please remember Engle/Mondello cams have a tendency to be noisy on their own, especially the larger ones. I had the 18-20 and it was a bit noisy. You may be stuck with that unless you replace it.

Hope this helps.