I have a custom built Procharged 496 R-tech intercooled engine making 825 hp at 6200 and I believe my oil t-stat is not working. After a quick top end run my oil pressure drops to 20 psi or lower at idle. I have to turn on my engine preluber to build more oil pressure. I am running a Hardin Marine oil cooler with a built in t-stat good for over 750 hp. The engine has a 10 qt. Canton oil pan,#12 oil lines, and a Hp6 filter. I am running 15-50 Mobil one oil. The cooler is plumbed with the t-stat end after the filter head. Engine temp never exceeds 160. Yesterday I made a couple of quick runs and felt the oil cooler. The by pass tube was hot and the main cooler body was cool to the touch. Unfortunately my oil temp guage has not worked all year so I have no idea what the oil temps are. Bad oil t-stat in the cooler?

I don't think just grabbing the bypass and saying it's hot is very accurate .How hot .Check with an infrared.20#'s at idle isn't bad with hot oil .JMO

You cannot expect an acurate response without knowing what your oil temp is.

I have the same cooler on my 775 hp whippled 540. I read oil temp at the filter housing. At high rpm I get up to 260 degrees. When I bring it down to idle, pressure will be in the high 30s, and temp quickly drops. I have no T-stat and engine temp guage never rises. I'm not sure you should build engine temp either.

The small hard oil line on top of the cooler is always hot. The cooler is designed to mix the hot and cooled oil, not to make the oil hot and cold.

Fix your temp guage and you will know if the cooler is working or not.

I've got a lazer temp gun. Stop by when you're up and you can borow it.

Kurt

Thanks Kurt. Will do. I'll try and get the damn oil temp guage working too before I see ya. Chris

Do you have the oil entering the oil cooler on the end with the thermostat? If not, it will not work correctly. The oil must enter the cooler in the end that has the thermostat.
Eddie

Yes I do have the oil entering the cooler at the thermostat end. I did neglect to say that the oil pressure gauge is electric and not mechanical. I was just told by a fellow gearhead at work that is not good and I should switch to mechanical asap? Thanks