The Stovebolt Site Forums The Shop Area Engine Shop Broken Rockers

For those of you that are new or are unaware of my rocker problem this is a short history. I have broken 12 rocker arms on my 51,235 hydralic engine in the 1 1/2 years. Nothing I did would fix it or quiet down the engine. For those who have followed this, especially Stuart. I finally solved it. I had the head gone thru when I was doing the restro. I was starring at the engine trying to will it to talk to me when I noticed the slot in the valve stems. The head shop put the valve spring keepers in the wrong (lower) slot. They are suppose to be in the upper slot. The springs were too compressed. I pulled the head, put in new springs and replaced the keepers in the upper slot. She is quiet and runs like a champ now. The old springs were hell getting off. Alot of you guy's really tried to help and I really appreciate that. Thx. Now I can go cruisin.

Glenn,

Glenn,

In the end, it was you that solved it...the engine really did talk to you. Congratulations, it's great you took the time to touch base with the outcome.


Stuart

Glenn, apparantly I missed your earlier posts but thats quite a story there. Another case of Murphy's Law in action.
A competent rebuilder would have caught that immediately because...when the valve face and/or the seat is ground it causes the valve stem to grow 'longer'. Upon assembly the springs are first checked for proper tension at a particular length & then when assembled in the head they are checked for 'installed height'. Most always some shims must be added under the springs to bring this dimension to specs. Ea. one must be ckecked seperately, &, if necessary, taken apart & shimmed. These specs. are available in a shop manual & in a chart form the shim mf'g. supplies. This has been S.O.P. for valve assembly at least since the '30's.
Glad you were smarter than your engine builder & got it corrected.
Doug

I thought that someone had mentioned spring bind as a possible cause. I recently saw pictures of a rebuilt 235 that had the valve stems extending well above the spring retainer and wondered about that.