When I got home I noticed the oil pressure was lower than expected. I wrote this off to the "sticky" Smiths oil pressure gauge that was in the car. Later in the day I replaced it with a trusted VDO gauge that is known good.
Now I am unhappy. The Smiths gauge was apparently right. THe engine starts from "cold" with oil pressure around 60 PSI. After idling for 10-15 minutes the pressure at 1000 RPM drops to about 40 PSI. Let the car idle 10 more minutes and the pressure is in the upper 20s. This is fresh 20W50 Castrol and of course... all the bearings are new. The ambient temperature is about 70 degrees F and the engine coolant is running close to the thermostat's 180oF rating.
The main bearing clearances were running 0.002/0.003 and the rod end clearances were running almost exactly 0.0015". The oil pump clearances were all well within spec and the endplate was flat and without scoring. The machinist "said" my cam bearing bores were in spec. I trusted his measurements because I didn't have a good way to measure them. I suspect the low OP is from the cam journal clearance as it is the only thing I didn't measure myself. I have an oil cooler that I could fit. I had hoped it wouldn't be necessary but now... I'm not so sure.
Then there is a confusing oil leak. At the moment the only crankcase venting is via a draft tube off the valve cover. There is no PCV valve connecting the the valve cover to the carb. The leak I am seeing is THROUGH the distributor. There is oil dripping out of the vent hole on the bottom of the Lucas 45D housing. There should be little blow by at this point and with the valve cover venting to air there should be no pressure to drive oil up and out the distributor. Have you guys seen anything like this before?
All in all the restart has gone well but with the temperature relatively low today I am concerned about what the oil pressure will be next summer. Your comments and suggestions concerning the oil pressure and leak will be greatly appreciated.
Doug L.