Valve seat doesn't seal

[Enea]

Hi all, I have a problem on n°2 inlet valve on my pinto group1 spec head, basically it didn't seal at all (vacuum tested on a serdi), checked the valve and it was slighty bent, I did resurfaced it and it works on other seats.

But on n°2 seat any other valve doesn't work, because the outer edge of the seat has sunk, so there is a ridge where the valve is going to touch... why a newly made seat did fall like that?

Initially I thought I did over revved it, but I checked and I have like 7-8mm of valve travel before it exits the combustion chamber, plus the head gasket thickness.... so to bend a valve on slight over rev it looks strange.

[Enea]

Tomorrow I'll try with a PEG valve grinder to manually remove the ridge, if it doesn't work, I'll cut the seat...
If it come to worst, it will be a new insert.

My question is, how can this happen, is it too much heat? I didn't have any temperature problem during the last 3 rally

[Enea]

Had to cut it new, went down more than 1mm, it was also at angle, basically the seat wasn't pushed all the way down and it fell in a few days of racing. Hope the others don't have the same problem...


I'd like to say that you get what you pay for, but unfortunately it's not the case.

[onecamohv]

thats a very interesting case, one to log in the memory bank. thanks for sharing Enea

[Graham]

sad to say thats not un heard of, except its unusal to insert an inlet