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Folks,
I’d like to do a “Lessons Learned” from what happened to my
engine this past weekend at VIR.
I
had measured and replaced my valve springs before the event. I had found
that the installed height was off by .008 all the way to .060. I blamed my
machine shop for not paying better attention while assembling the heads.
Having had the problem of 7 degree keepers pulling thru the retainers, I
had installed 10 degree keepers and a set of titanium retainers. (2 ½
seasons ago)
During
the weekend, my oil pump broke in two and I had found the end of a push
rod in the pan. Fixing all of that, the engine laided down again/ low
power/ 6 or 7 cylinders during the Saturday race. I found another push rod
that was hammered short. Not twisted of broken. I thought that I missed it
the first time and replaced it. This made one on each side of the engine.
We raced Sunday and …what a surprise…it broke again.
At
the autopsy yesterday, with intake off, I found a piece of one push rod
and 2 lifters in the valve galley. The long piece of the other push rod
was behind the cam gear. (someone explain that).
So
what caused the push rods to be able to jump out of the lifters?
The
titanium retainers/ 10 degree keepers were pulling thru on all of them and
the body of the roller rocker was hitting the retainer instead of the end
of the valve. It all hit me when I thought back on having to shim up the
new springs. I’m headed to the shop to go eat some crow this afternoon.
MORAL
of the STORY: Titanium Retainers also have a finite life.
Gary
H. Henkel - NASA American Iron East Racer
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