Oil pressure problems

[Gunslinger]

I knew I fell in with the right bunch of hoodlums !!!

I'm going to put the new Oil pump on thursday night, If it works I'm headed for the range with lots of noise makers !!!

[Carls_jeep]

I drove my Jeep today and the oil pressure stays at about 40 psi all the time. I am not liking that so I will put a test gauge on it to see what it really shows. It should go up and down with the engine speed.

Don't burn any barrels out but do have fun.

My son bought a M1919 .308 semi auto kit and we built it and got to test it last week. It fired just fine so now he will have it Parkerized.

We went to the Machine gun shoot at Know Creek last week end. It was a blast    

[Carls_jeep]

I checked the oil pressure hot with the Jeep guage and it's about 25-30 psi at idle and about 45 psi at speed. I would guess that someone screwed the bypass in at some time in the past.

[Gunslinger]

I'm Jealous !! I want to go to a Machine Gun Shoot! Up here in the state where nothing is allowed they get a little bonkers down at Gun control central when someone tries to set up a little automatic meeting.

I'm headed for the garage, going to put that NOS pump in and see what happens.  I'll keep you posted.

[Gunslinger]

Hey guys, more fun in OP land, I changed the oil pump and put on a brand new NOS pump, made a big difference, but it did not solve the problem.  At cold idle I now have 45-50 psi, with straight 30 weight oil.  As it warms up the op drops to about 40 psi, still good. I drove it about 2 miles and the op went from 40 at 2500 rpm to 20 at 2500 rpm and 0 like not on the gage at all at idle.

So now I know a couple thngs, my other oil pumps were pumping oil, but had some problems and were not up to full capability. I also know I've got a problem inside, I suspect one of the main bearings is not fully up to tight.  Shes going in to the shop tommorow to have the pan dropped.  I'm not well versed in crank bearings so I don't mess with them.  I'll keep you posted, we should be at the end of the journey Friday night.

[F Bill]

While you are in there take a really good look at your pickup assembly.. If you haven't already taken it apart and cleaned the screen now would be the time... and check the pickup tube for possible leak areas.. Definitely a headscratcher ya got there..

[rocketeer]

When the engine was apart did you do anything with the timing gear oil jet? It didn't get left out by any chance did it? In order for it to drop to zero on idle there has to be more than just a poor fitting bearing cap. A missing oil galley plug or timing gear oil jet could cause it.



Larry

[jamesr]

I brazed the .070 shut, and redrilled with a .040 when I rebuilt.  My engine holds 40 lb at 1000 rpm +, and 25 lbs. at less than 1000 rpm, hot or cold.  I suspect as wear takes placee these pressures will drop.  Jim

[Gunslinger]

Hey guys, good stuff, we put the jeep up on the rack this week and pulled pan, lots of wear metal in the pan, now remember, this engine has about 15 miles on it.  We dropped center bearing cap and wooowee, this bearing looks like its got 100K on it.  worn down to the copper in a couple places, the crank is ok but we are going to hae to repolish it.  Botom line is the motor is coming back out this weekend, and going back to the guy who built it for me.  It also looks like there is some kind of grit in the pan, so maybe when it was boiled out they missed a pocket of grit.  Any way ground zero, but I am going to look at that oil nozzle, that sounds like the kind of thing that he may of overlooked.

Thanks for all the help, I'll let you know how the re re-build works out.