041 head with sinking exhaust seat.

[Matt Schlicht]

I have a pair of 041 heads.  I have another sinking exhaust valve.  I have had one repaired in the past. I forget how much it cost to repair.  Would you repair it or just start over with a better cast head.  I had the bergs do the repair last time. I may shop around if I decide to repair it.

[Jerry D]

If the head was ever overheated it will soften the alloy and allow the seat to sink. If that is infact the case, I don't know if it can be fixed.

[John P]

I had a similar problem about 17 years ago, which ended up being attributed to a poor casting (there was a bad run of them). I swapped out the heads as attempting to repair it seemed like throwing good money after bad.

Again, this was with a known bad casting. If it is the second time this has happened on the same set of heads (and you know that you haven't overheated them), I would replace both heads.

I've never tried to repair a sunken seat on good casting, and will defer to the head experts.

My 1.5 cents.

JP

[Ohio Tom (DdK)]

I agree about the possibility of a soft casting. I have seen guys dump tons of money into re-seating soft heads only to eventually give up on them.

The only other thing that could cause it is severe valve float. 
Usually on the intake valves first (since they are the heaviest).

Or, the "press fit" was not good on the exh seats when they were installed originally. Was it the reparied one that failed again or a different one?

The other option you have is to re-seat your heads and go to 35.5mm seats (from the 041 standard of 32mm).
This would allow the machine shop to re-establish press fit on all 4......
IF that's the problem.

Otherwise, it sounds like you need a new set of heads.