Hi all,
Some of the many helpful frequent contributors may recognize I have an
ongoing absurdly longwinded rebuild thread (just like the rebuild itself) but I wanted to pose this question separately since it's fairly specific. About 2.6 seconds after I got off the phone with Ken last week ordering every single moving part the Atomic 4 possesses, I realized we hadn't discussed the camshaft. In other contributors' rebuild threads, the only consideration I had seen regarding the camshaft was the relatively "soft" brass(?) camshaft bearings that could be damaged by "hot tanking" the block or careless reinstallation of the cam. In absence of any clear direction I took my camshaft up to the machine shop who's doing the block work. The shop owner took a look at the cam and cautiously advised I send the cam off to get "cleaned up" and "hardened" and provided the contact info to a company in Oklahoma. (I'm rebuilding the engine at home in Denver even though the boat is in San Francisco) He expressed concern over the surface rust on the cam lobes and hypothesized it would only cost around $65-ish for the necessary work. Understandably, I echo his sentiment that "you've spent this much money/time/effort on this project you might as well leave no stone unturned."
My question is twofold. First, based upon these pictures would y'all be comfortable reinstalling this camshaft in a fresh rebuild? Second, does anyone know what "rebuilding" a camshaft involves? What does a 'hardening' process involve? Assumably if any material was machined off the camshaft, like a crankshaft, would likely need to be replaced with weld and polishing? What about the lobes? How would they assure the profile remained unchanged?
Before someone suggests it, I'll point out that yes, I know our great host sells used camshafts for $125 and that's obviously an option. Frankly my only hesitation is that even the picture in the MMI catalogue appears to have some surface wear on the lobes as well. Moreover I'm just interested in whatever wisdom the braintrust has to offer on camshafts, hardening, tappets, best practices, etc.
