Some engine rebuilders remove the relief valve seat as part of their
regular cleaning routine. A picture of the removed seat is here;
I brought this up because the seat could have moved or wasn't fully
inserted into the relief bore. it's easy to image how this would upset
the spring calibration, but I don't know what other implications it
could have. Just another avenue to explore.
Wm. Severin Thompson wrote:
>Nothing looks out of the ordinary in the recess. A anumber of plungers and
>springs were tried.
>We'll not know about cam bearing issues until I tear it down.