Vern-o-therm and oil pressure?

[FP1201]

When I first got my PE90 it had over 200psi of oil pressure cold, then would drop in the 50psi range once up to temp. Now there was something screwy with the vern-o-therm (sp) unit on top of the block, and for what ever reason I changed it with one off a PE150. Last time I ran the engine it was loosing a lot of pressure, it would keep enough above 1200rpm, but dropped hard at idle.
I think what happens with these units is they open/close to allow oil to bypass and dump right back into the engine above the crank. Now there were something like three or four of these located in various locations on the PE150, I can't help but wonder if they are regulated differently, or if just plugging it were oil is stopped all together is good-bad-indifferent? Not the problem?

[Rich863]

Hey did you ever find a solution to your problem

[FP1201]

Hey did you ever find a solution to your problem

No never really did. The engine only has one, while the manual shows several in diffrent locations/items depending on model.
I pulled the one on it apart: it was rusty, had water inside, but wasn't stuck. They have a 15/16" rubber piston (think drum brake cylinder) and as far as I can tell when oil hits the piston it pushes the shaft out and allows excess oil to bypass into the block. (The lower hole is oil galley, and the upper just dumps into a hole at the top of the case) At first I was thinking the spring might be temperature sensitive, but I don't really think it is.
Really, a 200psi gauge pegs until it gets warmed up, then usually has normal or at least accetpable oil pressure.
IIRC the manual says 30psi at idle (900rpm) and 50~60psi @ 2,500 RPM
There's a brass acorn nut on the side that I believe holds the bypass valve: as soon as I can litterally un-bury the boat, the plan is to finish the fuel system and tinker with it....got an ice fishing derby Feb. 21.

[dusty burch]

Funny gpu s dont have a vernatherm