Proper Oil Pressure Range Question...

Anyone know what the proper operating oil pressure range is for a OA331 Gasser Motor? It's for my 1953 Reo M35. My exisiting oil pressure guage shows 0-60 PSI and starts off at around 35 PSI Cold and then drops to around 20 PSI after warmed up and driving around for a while.

I was looking at replacing the gauge and sending unit, but Saturn Surplus only has 0-120 PSI which got me thinking that maybe my pressure is too low.

HMMmmmm... Let me know what you think. Any help would be appreciated.

Thanks,

Tyler

All is fine... anything over 10 psi warm will keep you rolling. A mechanical gauge will solve your quandary.. remember to match the sender with the gauge....when you are doing the electric stuff..They went to 120 when the MFs pegged the 0-60 gauges...requiring a new sending unit too.

The military manual doesn't offer much for details of proper oil pressure. The civilian manual for the OA331 lists the following: 5 to 15psi at idle, 35psi minimum at 2krpm, and 40 to 60psi at governed speed. Unless your engine is REALLY worn, it should start out with more oil pressure when cold. If it is really that low, I'd find out why. I had one with pressure that low and it was bad mains.

Engineers rule of thumb is 10PSI for every 1000 RPM.

My gasser V18A /MTQ is about 70 psi cold and 40 psi warm. Rotella 15w-40 and mechanical gauge and 3500 mi on overhaul.

Hmmm. I hope its not a main going out. I just dropped the oil pan today to replace the gasket because of a rear end seal leak. Turns out that there was no gasket on the sides and the cork front and rear seals were almost non-existent. I'm starting to think that the previous owner did really shotty work and half a**ed everything he touched. Anyways, didn't even think to check the bearing when I had the pan dropped. Bummer... Think I'll invest in replacing the gauge and sender and see what takes place. I've been using about a 50/50 mix of Lucas Stabalizer and 30W oil. Was told to never use anything but 30W... Any thoughts on this? Why not use a heavier oil like 20W-50?

Thanks again for your humble thoughts. I've got manuals for the Multifuel but very little on the OA331 Gasser...

Recovry4x4 said:

Engineers rule of thumb is 10PSI for every 1000 RPM.

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Not this engineer's rule of thumb. Oil pressure requirements depend on more than rpm. If something is abnormal, don't wait to find out why.

The military manual doesn't offer much for details of proper oil pressure.

Click to expand...

TM 9-8023-1 (gas engine and clutch overhaul manual) says to put a mechanical gauge in place of the electric gauge sender. With the oil at the proper level, the engine at operating temperature, and running at normal speed (3,400 rpm) the pressure should be 45-50 psi.

That's detailed enough for me!

Jon

As already mentioned check OP with a mechanical guage BEFORE you do anything else. My M37 and both my deuces and my 5 ton read half on the elec OP guage to what I got when I hooked up my mechanical. Also if your running 50/50 Lucs your no longer in the 30w bracket anymore, more like 50-60w now

my 6602 runs 50 lds running 2000 rpms and a little over 0 at an idle. been like that for 5 yearsand 3000 miles now.

my m882 has a 318 and it is 60 at start up and 25 at idle warm