A little education on cam regrinding...
I'm getting several emails
asking how grinding a cam "down" can possibly increase lift or
duration.
Let me start with the terms used for opposite ends of the cam lobes themselves.
The longest, most pointed end of the lobe is referred to as the
"toe." The smallest part, 180 degrees opposite the toe would sensibly
be called what? Right, the "heel."
To increase the duration on a stock cam you remove material from the toe. This
will effectively create a milder radiused, less
pointy lobe just like on the higher duration cams you'd buy from Schrick, et al. To increase lift, material must be removed
from the heel section of the lobe.
The secret in finding the best combination is no simple feat. Everything is a
compromise, a trade-off. More duration moves torque higher in the power band.
The key is to find an ideal compromise, ie; one that
is perfectly suited to your needs/wants. <grin>
good luck determining that but please, feel free to share it with me if you do.
The benefits to regrinding are lighter weight, more lift and/or duration. You also
effectively lower the base circle of the cam.
Cost: I've found prices for our cams from $190 on the low side to $299 on the
high side for a pair. Additional services like flame hardening, parkerizing or surface treatments would be additional.
Re-grinds are safe and should last as long as stock cams. They're even approved
for aircraft overhauls. Only when you start adding material to cams is there an
element of risk associated due to pitting/cracking or separating of the built
up area from the base metal.