Oil temp/pressure

Gauge accuracy occurred to me but I'm afraid that would be too lucky. And the more I read about the relief valve possibly being the problem (such as at other blogs for Aeronca, Fly Baby, etc), the more it sounds like that's a pipe dream as long as the cold pressure on startup is ok (40 psi in my case).

No, I'm afraid there's no way of getting around the reality that the problem is deep in the engine. This poor plane has been fraught with such problems related to poor maintenance since I bought it. The last big one was propeller replacement because the one on the aircraft didn't match the serial # in the prop log and failed specs at overhaul. Maybe the *$!#@&'s had a prop strike, changed out props and called it good for all I know.

Thanks all for the advice though. Always good to stir things up a little in the forum.

Chris

That is good news. What about the camshaft bearings? Have you tried another direct reading gauge? It could still be the pump/ relief valve.

Case overhaul and crankshaft ground by Aircraft Specialty Svcs in Tulsa approximately 300 hours ago.

Even 50 weight oil gives low oil pressure when hot with worn bearings or pump. Did they turn the crank on the last overhaul or just put in new bearings on a worn crank to save money? Oil pressure on older cars drops as the oil heats up, even with 20X50. Worn bearings.

What's strange is that it's so temperature dependent. Multi-grade oil is supposed to retain its viscosity throughout the operating temperature range. Why then would the low oil pressure seem to be so temperature dependent?

Spin on filter is replaced with each oil change. And I've heard of adding washers to the high pressure relief valve Larry but the consensus is that it's a pipe dream. That valve only comes into play when the oil pressure is too high. Adding washers would raise the pressure at which the bypass channel comes into play but do nothing for the cruise oil pressure when low.

Nope, I'm thinking the accessory pad is gonna have to come off and pump gears and housing will need replacing. I seem to remember that you're right Bruce and this has to be done with engine off of mount. Anyone know any different?