520 hours since overhaul less than four years ago. I think maybe they were reconditioned one time too many.
New parts going in this time.View attachment 44302
520 hours since overhaul less than four years ago. I think maybe they were reconditioned one time too many.
New parts going in this time.View attachment 44302
Cold starts, doesn’t take long/QUOTE]
I preheat below 60
Yup, something like the case hardening?I have seen folks regrind what looks to me to be very serviceable tappers and cams. I think, without any evidence, that regrinding removes something important.
Yup, something like the case hardening?
Looks like a complete engine's worth. Why are four of them destroyed and the other four just starting? That is the mystery to me. What else was happening in that engine to cause that extreme damage to just those four? Exhaust valve guides too tight? Something else?Intake, exhaust, or mixed?
Gary
I think that the person who placed the yellow tag on the tappets needs to rethink what he is doing since he certainly didn't do you any favors. Those tappets should have gone to the full TBO or in the trash rather than the crankcase.I think the simplest explanation is the most likely cause - the yellow tagged tappets were past their useful life and failed.
It looks like corrosion played a role. How bad is the cam?