Hey guys,
Ive got an aftermarket cam, lifters and pushrods on my motor. Its not beat on or anything but recently it wore down a couple cam lobes and lifters. The exhaust valve clearance went really wide on 2 cyls, which is how the shop noticed it.
Any idea on what would cause something like that to happen? Im hoping that I didnt have something major damage the cam journals in the engine, allowing it to flex or something crazy like that.
Assuming the journals are ok, what else could cause that to happen?
Ive always run 15-40 diesel oil in there, rotella or valvoline. has amsoil synthetic 15-40 in there now. Oil pressure shows as 40psi when its iding. I change it pretty frequently since it soots up so fast, so Im really stumped by a failure that makes me think oil quality / pressure.

 

What about oil to those lobes? Pressure might be ok to the gage but to that specific area? Just a hunch- the other hunch is the cam itself - I know nothing of Hamilton, but according to Cummins the valve lash adjustment period on these trucks was extended to 150K miles because in practice they found zero wear occurring. Just had mine set @ Cummins NE in Dec.

I would look at the parts themselves - early 80's SBC engines were none for eating the lobes off cams in the rear cylinders from oil flow issues, could be the same or the parts themselves - bad treating on those lobes, etc.

 

Hamilton makes some top notch stuff.. so my guess is either the shop did (or didnt) do something at install time, or a gallery got blocked. Possibly a bad cam got through QC but I doubt that.
Ive seen some mfr's of race cams recommend a break in procedure with high zinc content oil. Not sure if hamilton recommends this or if the shop did it.
Im debating getting a ported head on there while hes the other stuff off.

 

When I bought my cam from Colt, Geoff and Zach were still in a partnership, same cam, same break-in procedure. High zinc additives were highly recommended. Did you install new or resurfaced tappets?

Pull it and take pictures. I'd bet that Zach would want it back to see what went wrong with it.

 

Im having a shop do the work since I dont have a garage to work in. When the cam was installed I got all the extra stuff from hamilton to go with the cam. The 24v tappets, the pushrods, springs..
Theyre sending me a new cam for free since the assumption is that its a cam failure, but I suspect something else is going on. Maybe an oiling problem I dunno. The shop is sending back the cam for him to check out, but I think looking around in the block would give more info on how it failed. Maybe Ill hear back from them today on that.