According to everything I've read (and who believes that) the cores that
cams are made from are flame hardened well down into the barrel of the
cam, so regrinding doesn't require rehardening (which is a good thing--I
can't imagine how you could keep them straight). 35Rc is pretty soft.
There's a lot of variation (you can purposely create some very soft cast
iron) but most "hard" as-cast cast iron stock has a brinell hardness of
200-350 which is roughly 30-33Rc. I've never understood why there are so
many standards for metal hardness. Then again, I've NEVER understood why
there's a Whitworth standard (what goofy bolts those are).
-----Original Message-----
From: Larry Young [mailto:cartravel@pobox.com]
Sent: Monday, September 09, 2002 11:19 AM
To: TeriAnn Wakeman
Cc: FOT
Subject: Re: Lifter Hardness Confusion
Greg Solow's post in January said he typically gets 52 to 55 for OEM
lifters. I just had a set tested that ranged from 48 to 53 (note: these
were measured on the 15-N scale and I'm converting to Rc).
I have it straight from Steve Long, who's taken over for Erson, that his
reground cams are not rehardened. He said there is some residual hardness
of about 35 Rc. So what hardness lifter is needed? I'm one confused
Okie. Larry Young
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