Cam polishing/regrind/repair
 

Anyone ever done this?

My new Crane roller cams 4 rear lobes have some discoloration and some very minute pitting in spots from runing the motor this summer too cold. Also can feel a different texture with fingernail. Major condensation problem. The areas are where the lifter sat in contact on the cam. :( I am guessing that they would clean up with only .002-.003 removal.
Lifters are shot. Under microscope, they showed what looked like fracture lines around the outline of the rust marks. If only the wheels could be replaced, but no will do.

Crane wants $25 to polish, $175 if regrind needed. ($250 new). Curious if they are magnifluxed when rechecked.
I take it that regrind does not change the profile, just the rocker arm height.

Thanks,
Jerry

I would think that with regrinding the cam, you would need new push rods. Guess the easiest way to check would be assemble the engine and make sure the roller is centered on the valve.

I would think that regrinding would take minimal material from the cam,somewhere around .005-.010. This would include reducing the size of the base circle so the cam profile remains the same.

Why bother buy a new one and forget all the greif....my.02

Just sent it off to Crane to be looked over. They said if it is too bad, they will just replace it with a new one for the cost of a regrinding. Cool! Sure beats paying full price to replace a cam with less than 40 hrs!
Jerry

I am certainly no expert here, but would be curious about a couple things;

If you remove material from a cam lobe, how can you not reduce either the throw (lift) or the duration if nothing else changes?

Do you think the condensation/oil temp problem caused the cracks in the rollers? If so, are they significant enough to warrant a reaction to their presence, or are they superficial? Superficial cracks in and of themselves should not affect perf or reliability.

What have you done to better monitor the oil temp and reduce condensation? Symptoms are best treated with an affective cure.

Lastly, I always vote for all new stuff. I get really pissed when I have an engine failure in mid season. When in doubt, pull it out.

Good luck,

BT

The whole cam lobes are reground. This maintains the original profile. A couple of .001's won't effect the pushrod length. I bought the oil filter/t-stat unit that is used on the HP500's now. Plus the I'm having water lines connecting the rear and front water jackets on the blower intake installed and having the crossover and stat housing worked over so that I can use a t-stat. My water temps never went over 100*, even after long hard runs in the hot summer days. I knew it wasn't good, just didn't know to what extent it would harm the motor. The lifters are being replaced with new. I think the pits are to much to overlook/chance. Crane is going to call me after they look at it with their recommendation. They say the flame harding is .110-.125 deep before original grinding, approx .080 after grinding. With it only needing a couple of .001's to clean up, it will be basically a new cam. Unless I can pursude them to just replace it. ;) If there is any question, it's going bye bye. Should know within a week.
Jerry

I agree with Crazyhorse, also this will make your lifters drop down a little further in the lifter bores slightly.

UPDATE
 

Crane said all it needed was polished and has sent it back. .........at NO charge. :D Wonder if they do blowers? ;)

WOW USFoutain, that is service. I guess you'll buy more cams from them in the future. I hope it works for you. Polishing should not affect the throw of the cam at all. Pretty sure regrinding would (my job has a lot to do with cams) , but that's a mute point. Saw your boat on reader rides... sweet, sweet ride!! Do you do all your own motor work?

Springs approaching and I should be dropping the sb motor in this weekend. All new upholstry is ready, assembled dash with new gaffrigs tonight and still wrestling with the carrier bearing although I got the tool today that you told me to get. Still looks like its gonna be a total b**tch, but that's half the fun. Thanks so much for all your help!!!!!! I just wish I could help you more.

BT