Right... if the relief valve was working the pressure would always be limited to that. So it does sound like the valve if it blew the filter gasket. Odd that it was OK on the stand, now I wonder about the stand gauge... 80 psi is not one of the standard pump springs... 72 and 55.
might have been closer to 70 on the stand but not over 80 and didn't spike or leak like it is now.
BTW, what oil weight OP? Just for info....not that I think it is the issue.
cam beak-in was with 15w40 rotella then changed to 20w50 vr1 which has been run in this engine since first built
That's stuck open. His sounds stuck closed.
