When I put my new motor in, I put the headman longtube headers on it. With those headers you can't really put the oil cooler lines back on. Now, my question is about oil pressure and oil temperatures. Thereoretically the oil cooler cooled the oil a decent amount. Cooler oil equals more viscous oil, which in turn means higher oil pressure. I installed an Autometer guage about 2 months ago while it was still cold outside. After that I would never see the pressure go below 25, and got up as high as 65-70 when cold first started. While diagnosing an electrical problem I unplugged the oil pressure guage. After fixing the problem I got lazy and didn't put the guage back till today. It's now alot warmer than before. After I put it back on I've seen the pressure down to 12.5 at ilde in park at temp, 25 at idle with no load at temp, and 37-40 on the freeway at temp. Now, if I put an aftermarket oil cooler on, will my oil pressure get higher at all? I would assume that my oil is getting hotter than it should be.

I've heard people say that the oil cooler is a piece of crap, but in my opinion a car company won't put something on a car unless is serves a purpose. They are way too cheap and cost minded to do that. Maybe I'm loosing 20-30F, and that is lowering my pressure 5-10 psi.

Ryan

 

TTT

 

The factory "oil cooler" was designed for cars that sat and idled alot with the air on. The oil gets its hottest under those conditions, in a street car. That cooler has little effect on a car that's running down the road.

So, yes the factory put it on there for good reason; but the reason wasn't what we as hot-rodders might want to think it was.

I doubt that your oil pressure change has anything to do with the factory cooler; more likely a different kind of oil, or needs a new filter, or the sending unit is going bad, or any of dozens of other things that can affect what that gauge reads.

Yes a real cooler may in fact raise the oil pressure a little bit, when the engine is fully hot. Or it might lower it, from adding flow restriction to the system. Hard to predict, really.

37-40 at cruise is lower than it should be. Even cars without oil coolers have more pressure than that, with their engines in good shape. I'd suspect a gauge issue rather than an actual oil pressure issue though. Try a new gauge sending unit before spending a bunch of time and money on something that may do nothing at all and might actually have the opposite effect fom what you intend.

 

I'm already using an autometer electric oil pressure guage. That's where my readings are coming from.

My theory is as follows...
i was getting close to 70 psi at temp on the freeway when i first installed this autometer, but it was in the 20's and 30's. Now that it's warmer out, 60's to 80's, the pressure seems lower. Now you might think my car is just running hotter in the higher temp times. Well, you would almost be correct. The said pressures are both at 160F engine temp, cold outside and hot outside. The car warms up faster now. The thing is, i haven't driven the car after it sat all night since it's been warm. I'll do that soon, and see if the cold temps are close to 60 or 70.

Another theory/question....
A mechanic I used to work for told me that any SBC technically only needs 20 psi while moving. Now how long a motor will survive like that is another question. He just said it would survive. But this is the same guy who I suspect is the reason my motor spun a bearing since he put standard 10W30 in my car without telling me, and I had been using 10W40 full synthetic. Oil pressure dropped and I spun a bearing.

Thanks for the help
Ryan