Just an update, we removed and inspected the oil pressure releif valve plunger.
It looked a bit uneven at the mating surface where it rides on the accessory housing.
We took a new one, lapped it to the case so the surfaces match eachother.
Test flew it for an hour with a slightly richer...
One other thing I failed to mention, we manually blocked the oil pressure relief valve and cranked the engine with the mixture out to verify that the pump was building adequate pressure. It almost immediately made 60psi so we know for a fact that the pump makes plenty of pressure.
This would only manifest itself in an external oil leak as well as the pressure readings correct?
Other than that I’d need to pull the kidney and closely inspect where the case meets the crankcase right?
I’ve never ran the engine with the old accessory case in it, the previous owner mentioned the priming issue when I went to buy it, I was unable to get it to prime just cranking with the mixture pulled out so we started investigating before we caused any additional damage.
We are running Phillips XC 20w50.
I have a case of straight 100w on its way as I’ve seen some say it makes a noticeable difference.
I’m a bit skeptical as SAE50 is SAE50 regardless of whether it is a multi grade or not. But we’ll give it a shot.
I like the idea of running an oil filter on it...
Thanks for the very in depth and concise response!
My airplane still has the old mechanical bulb style temp gauge as well as the original pressure gauge.
Yes. The loss of prime is why we went as far as we did.
The previous owner had this issue, and I wanted to fix it before I flew it at all.
It hasn’t lost prime since.
We changed the oil 5hrs after the accessory case replacement as it doesn’t have a filter.
The screen had a very small amount of metallic material in it, but none was magnetic and the oil has been clean since.