Quote:
: Sometimes the cam is bent! Of course if it's
: too far out, you have to send it back. I ran
: into 3-in-a-row with a CompCams HighEnergy
: A-engine cam several years ago. When I
: finally found an acceptable piece it went
: like hell!
: You've heard of line-boring a main line. Well,
: you can have a cam-brg line out, also. But
: think about it, you can't line-hone a
: cam-line. So, by trial and error, you use a
: bearing knife to shave out small amounts of
: the soft babbit bearing mat'l of the
: offending cam bearing shells so the cam can
: slide into place. I've had to do this a
: couple of times, the last with a 360 my
: daughter was building for a senior project.
Well stated Bud, it is pretty common to have high spots on the cam bearings and if you install the cam, spin it a few times then inspect the bearing surface, you will see them.
It is always good to check the run-out of the cam before shaving the bearings but if the cam is straight, some hand scraping really helps free-up a tight cam.
I have had to do this enough that I made-up a special cam "cutter" by machining some grooves into the journals of a worn-out cam. I slip this in and carefully spin it, remove the cutter, test with the new cam and if needed, clean the scrapped babbit out of the grooves of the cutter cam and go again untill all spins freely. This goes a little faster then using a bearing knife on each individual bearing.
DD