oil pressure

[geraldchainsaw]

running down the highway i have 60 lbs pressure,  at idle i have only 5 or 7 lbs, right now i'm using 10-40 weight,    do i have anything to worry about?,   would going to a straight 50 weight help me any?,   or do i wait until something happens??,   i know a rebuild is in the future,  maybe closer then i think,   opions r what i'm looking for,   thanks    jerry

[4banger]

As long as you have 10 lbs. of oil pressure per 1000 rpm you will be ok.  example : 20 lbs-2000 rpm, 30 lbs-3000 rpm, etc,etc.

[JimNolan]

Jerry,
  Since you know the pressures I'd assume you have a mechanical pressure gauge. That's good. Since you have a 312, telling you to listen to the lifters at idle won't help. They rattle already. You've got two things that could be wrong. The oil pump is worn or the main bearings are worn. More than likely the main bearings are worn. Going to a heavier oil won't fix anything. The only thing you can do is pull the motor and change the bearings before the crank gets worn. That's a crank you need to take care of if it's a 312 you've got. If it's a 292 then you can get a replacement easily. I don't want to sound pesimistic but I've been through the same thing. I went to heavier oil, changed my oil pressure sender, changed my oil pump to a high volume oil pump and it didn't help. I had good oil pressure at speed but not at idle. I eventually found that the machinest had ground the crank on a taper ( long story) and the bearings were eat up on one side only. I hadn't checked the bearing clearance when I put the engine together. Live and learn.  Jim