Just put a set of DOVE-C heads on my 460.
All new valves/seats/guides.
Springs matched to the comp cam(.576 lift).
Crower retainers and keepers.
Also used Comp roller rockers and 3/8" comp pushrods.
Local machine shop did all the head work.
After about 40 minutes of driving time it dropped the intake valve on #2 cylinder.
Pulled the heads and returned them to the machine shop.
Just went and took a look at what they found:
Every single intake valve guide was elongated badly.
Side to side was normal, but you could move the valve up and down a lot with the head laying on the bench and the spring off.
All the keepers on all intake valves were beat to a pulp as were the spring shims.
I am using a 10 qt pan w/high volume pump, and Valvoline 20-w50 racing oil, so lubrication was not an issue and the motor was never overheated.
The guys at the shop are a bit baffled as am I.
What could have happened here?
Why were only the intake valves affected?
And why the extreme elongation of only the intake guides?
4800rpms was the most this motor turned, and again, it was only on the lake for maybe 40 minutes not including the 30 minute cam break in on the trailer.
Would a set of lash caps helped this from happening?
The machine shop is going to cover the head repairs, but I need to figure out why this happened so it does not happen again.