Oil Pressure

[icanfixall]

I have been watching my warm oil pressure and I feel its low. I have replaced the rear oil cooler header when I assembled my new turbo spec motor. My idle pressure is always around 15 lbs warm, its just the pressure when the motor is running around 1900 rpm going down the road. Its around 38 lbs. Now if I'm running at 2200 rpm it will be around 43 lbs. I have read the pressure should be between 40 and 70 lbs at 2000 rpm. I'm assuming this is a warmed up oil. So I'm going into the regulator and see why its low. I'll probably either stretch the spring or add some shims to it. I can make a shim pack from any thickness. At this point I really don't know how much of a shim adjustment I need. I may even build a test stand but thats some ways off right now. Any imput out there???

 

[Diesel JD]

That's about what I'm getting but my motor is well used. You'd think you'd get more out of a brand new unit. Let us know what you find out.

 

[9073]

spec is 40-70 at 2200 rpms according to alldata, your oil pressure seems fine


matt

 

[icanfixall]

I'm am aware that 40 to 70 is normal but.... My running oil pressure is low for a new motor and thats not normal in my oppinion. I'm sure I can run it the way it is but being on the low side of normal only means I wont have very good oil pressure down the line when I have more miles on the motor. I still may just pull the motor and mic all the bearings and crank again. Its not all that much trouble. I installed and pulled this motor 4 times because of the torque convertor pilot being size on size with the crank bushing. I do have another motor on the stand that I can build up if I find something really off on the motor in the truck now. I really don't have a reason for the pressure to be on the low side of normal other than something wrong on the regulating side of the system.

 

[sle2115]

Just for comparison purposes, and noting that I am taking oil pressure from the port on the d-side of the block, behind the oil cooler, not on it. I see 17-20 hot idle and usually around 44 to 45 hot at 2000, over 50 at 2500. I have an 87 with 140,000 miles on it. Everything is stock as far as I know, other than electric fuel pump and new water pump, nothing that should affect oil pressure. I would think you would have more as well and I know what you mean, there is a spec, but with a fresh motor, you would expect to be on the high side of the oil pressure spec.

 

[zigg]

That sounds to be about average pressure. Even after fresh rebuild on my present engine with new bearings plastigauged to fit etc, I still only see 65psi on a completely cold engine. Once it warms up, it is around 40 all the time at speed, and about 20 at idle hot.

I haven't heard of anyone who has pressure over 40 when warm.

I'm hoping to have my new engine up and running this weekend in my other truck, so I'll report how it is then, but it sounds a bit like you're might be trying to "guild a lily"

Zigg

 

[typ4]

Hey there icanfixall,
my new engine I built, meticulously checking all clearances, only has 40 hot and running at 1800, 15 hot at idle. I am going to pull the header and shim the relief also. I would like to see 50 at least. The other side is that they pump oil everywhere in this engine, not as much as a detroit but the piston squirters use up a lot of oil.
My oil pump was absolutely perfect so i know it's not an issue.
I will mod my relief this weekend and let you know how it turns out. Btw the turbo uses quite a bit also. Always wondered if that should be restricted but the factory turbo isnt soooo?
Read your sig, I also have modified prechambers!! feature that .lol
thanks again:
Russ

 

[LUCKY_LARUE60]

These oil pumps are "high volume" pumps not "high pressure" Did you check all the piston coolers? My truck has 62psi @ 1800rpm hot and my motor has over 200,000 on it, also where are you taking your reading from? Another thing is the cam bearings are what determines the oil pressure not main or rod bearings.

Jim

 

[Agnem]

I've seen the Moosestang presure drop to 5 or even 0. I think the gauge is flaky. As long as I see over 20 when cruising, I don't worry about it.

 

[icanfixall]

My readings are taken off the drivers side at the turbo oil port. I have also checked it on the main oil galley between the front and rear oil cooler headers. Same pressure. Why does the cam bearings have something to do with oil pressure other than they are part of the oil system. What could be wrong with the piston oil squirters. All they do is squirt oil under the pistons. I cleaned all of them. I wanted to be sure they were open.

 

[Greenbeast6.9]

i see 32 psi hot highway speeds, with the "newer motor", It has over 150,000 on it. The old motor had 300,000+ on it but it had like 45psi hot highway speeds. The new motor feels alot stronger and starts better than the other one when its cold.

 

[sle2115]

My readings are taken off the drivers side at the turbo oil port. I have also checked it on the main oil galley between the front and rear oil cooler headers. Same pressure. Why does the cam bearings have something to do with oil pressure other than they are part of the oil system. What could be wrong with the piston oil squirters. All they do is squirt oil under the pistons. I cleaned all of them. I wanted to be sure they were open.

I have never heard of mains/rod bearings not affecting oil pressure in any babbit bearing engine. If the clearance is too big in any of the bearings (main/rod/cam), it is like trying to maintain oil pressure in a bath tub, not going to happen. Main bearings have the largest surface area, therefore, have the ability to leak off the most pressure. If the clearance is right, oil pressure will remain stable. I know there have been arguments over what makes oil pressure and all that, but you can put a high pressure oil pump in an engine and make more oil pressure than a stock pressure. That holds true if the bearings are shot or not. I don't mean to say your bearings are bad or anything of that nature.

I think the oil cooler jets come into play in the same way. Think of it like a windex spray bottle. When you tighten the orifice, you build more pressure behind the nozzle and therefore it is easier to maintain system pressure. If you drill that same windex nozzle out to 1/8" hole, it is just going to slobber oil out because the pressure never build behind that nozzle, now multiply that times 8 and you could have a substantial oil pressure loss!

I don't know why you have this pressure, I am not even trying to say it is bearings or oil nozzles, just trying to offer up some ideas.

 

[h2odrx]

Sooo..... what is the best place to check oil pressure? Stock? or of the oil cooler? can some one post some pics?
thanks!!