There were some questions about how Cams and Lifters were hardness
tested, so I asked Steve Gruenwald, owner of Integral Cams, how they did
it.
His reply:
Dear Don:
We use a Rockwell hardness tester to hardness test the lifters. It
creates a small pin mark in the lifter face. When we regrind the
lifters sometimes this pin mark cleans up before the other wear marks
and sometimes not. It depends on how bad the lifters are worn.
Rockwell hardness checking is generally classified under "destructive
testing" but its not literally that brutal and in this case it only
means that the part can't be used "as is" after testing. We certainly
would not want to hardness check the lifters after grinding and
polishing them because the little pin mark would cause rapid cam and
lifter wear in an engine. So the only bad thing about this testing
method is that we can't test an already new set of lifters without
having to regrind and polish them afterwards. Another question I am
often asked is: when we regrind the lifters to make the pin mark go
away, are we grinding off the hardness layer and will the lifter now be
soft? The lifters are chill cast which has a broad diffused hardness
band so we don't have to worry about instantly grinding through the
hardness band like you would if the lifters were induction hardened.
Please let me know how you like your cam.
Thanks,
Steve Gruenwald
Integral Cams
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