Originally Posted By: BrocLuno
It's almost certainly the ADBV that is causing the issue, and maybe if you are running "synthetic" oil. You have not stated the oil?
Some syns tend to drain-off more than others. Slow to come up to pressure is a classic example of no ADBV and low surface tension (syn) oil ...
Put on the right filter first. Then think about the oil ... If it were me, it'd be Baldwin all the way
This does not look like a daily driver. So sitting and synthetics are not always a good combo ...
For a car that can sit a week at a time, it's often best to use a premium dino oil or a really good Group III.
For that classic engine, I'd prolly run Delo 400 15W-30 SD (severe duty). You don't need the SD part. But the premium conventional oil part would prolly help a good bit in offsetting any drain-off
First, I want to thank everyone here for all the kind comments about my '65 Rambler. You don't see many of these cars because they were cheap, use-'em-up, throw-'em-away vehicles back in the day. I'm fortunate the original owner's widow "allowed" me to purchase the car, but only after I promised to keep it in original condition. She has fond memories of riding in this ol' Rambler with her husband behind the wheel, and she still comes to my house to visit the car once in a while. She likes to sit silently in front passenger seat for a few minutes. I'm sure she's recalling good times that happened half a century ago.
But back to motor oil and oil filters ... I've been using conventional Shell Rotella 15w40 in the Rambler since I bought the car in 2007. It doesn't leak or burn oil, so I plan to keep on doing what I've been doing. I'll make certain the next oil filter has a silicone anti-drainback valve, then keep an eye on the oil-pressure indicator lamp (a/k/a idiot light) to make sure it goes dark immediately after starting the engine.
Again, thank you all for your advice and suggestions.