I have a 68 Camaro 327. Completely rebuilt engine, valves and all. Did not replace rocker studs. However I have replaced(3)rocker studs since the rebuild that had cuts in the side of them causing the rocker arm to sit sideways slightly and eventually would come off of the valve. Are the studs just worn from age since they were not replaced and I just didn't notice it on the rebuild, or is there something I am missing?? I have replaced the(3)with the screw in studs and that fixes the problem, just not sure what created the problem. Have not run into this before. But a definate cut in the side of the stud.
Thanks for any ideas!
old, (Name ??)
Take a look at the oblong holes where the pushrods pass through the cylinder head. If your heads have the stock, pressed in, rocker studs, then the pushrods should be a pretty "snug" fit in the holes in the head. That is all that guides them and keeps them from moving to the side. If the holes are worn badly, you will have to remove the heads and have screw in studs and guide plates installed. The other thing to look at is the tips of the valves. If they are not perfectly square, they can cause the same problem.
Hope this helps,
Advanced Automotive Machine
1971 Chevelle "Heavy Chevy" original owner
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Thanks Bill: I will check those areas. Makes sense and doesn't sound to extensive a repair even if I have to pull the heads to fix. Just ashame that the machine shop didn't see a problem.
Oh, the name ? I love old cars and I'm a San Fransico 49er's fan. So I put the 2 together!
I bet your rocker arm geometry is out of wack. I had an early 327 that the lifter bores were not correct. The thing would saw rocker arms in two until I put a set of heads on with guide plates that I could adjust. After I got everything right no more problems.
The oblong hole for the pushrod seems to be snug like the rest of them. The end of the valve looks square from a visual. The only thing that looks slightly out of alignment is the rocker stud itself. But just slightly. It doesn't look perfectly square to the head, but only a few degrees at most! This could be causing the problem. I have built many small blocks, and this is the first time I have run into this problem before. Oh yeah, Bill, my name is Kim! My parents were on drugs when I was born!!
Thanks for all imput!!
did you go with a higher lift cam? If so the rockers you have may not be long slot rockers. To much lift and kicking the rocker to the side?
Are the studs strait? You said you replaced with screw in studs, I would think you have pressed in? Could be bent studs or bending studs or loose pressed in studs. If all studs are drilled were they drilled strait/ I have seen a nice set of heads ruined once by a friend drilling his and not paying attention to his work.
Just some thoughts hope they might help.
The name thing about Bill, never knew that, but he must like me
"If you can leave black marks on a straight from the time you exit a corner till the time you brake for the next turn.......
Then, you have enough horsepower."
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