Don Terrill’s Speed-Talk

That oil pressure that is. My new engine oil pressure when cold at 7000 is 95# (70 degrees},It never goes this high because I don,t race it cold, except one to see how high it would go. When warm it goes 70# at 7000, How bad is this? I was thinking (I think once and a while) that I could make a "Blow off valve" for the outside of the engine. What you think Oldhead

That with 5/30 oil,I have made 5 runs at the 1/4 the other day. with no problem Oldhead

Used to be that the recommended formula was 10 lbs of oil pressure per 1000 RPM when the engine is at normal operating temperature. But this thinking has gone out the window with the availability of better parts and machining abilities. In actuality, 70 lbs of oil pressure is wasting valuable horsepower in a race engine. High oil pressure won't necessarily hurt anything, just wastes horsepower.

yeah, it doesn't NEED that much. but would not mess with lowering it now.

How bad would it be if I HAD to run it cold at 95# Oldhead

Only one way to find out!

I would never run an engine at 7000 rpm with cold oil, regardless of the oil pressure. Let the oil warm up before beating on it.

JMO,

paulie

95lbs cold at 7krpm is no surprise at all if you have any sort of improved oil pump and/or higher viscosity race oil. I agree it's way too much pressure for an engine, but the consideration there should be warmed up pressure not cold. Horsepower is proportional to flow and pressure. Increase either and the power to spin the pump goes up. Biggest risk I wound suspect is to your pump, pump drive shaft, and distributor gear.

As for a black and white "will it hurt anything"? I don't know..

Plovett, i agree 100 percent, i am a firm believer in preheating oil and then getting the oil to 200 deg. after starting before applying max. RPM, fanatical Mark !!

swampbuggy wrote: ↑Sun Oct 29, 2017 8:10 pm Plovett, i agree 100 percent, i am a firm believer in preheating oil and then getting the oil to 200 deg. after starting before applying max. RPM, fanatical Mark !!

Yes, until I put an oil temp gauge on my car I had no idea how long it takes to get oil up to temp, most people think it is once the water reaches 180 but it's not.

Oil temperature is very load sensitive; absent an oil to water cooler you can idle a car with no fan until the water hits 240° and the oil temp still willbe barely off the peg...

oldhead wrote: ↑Sun Oct 29, 2017 2:08 pm That oil pressure that is. My new engine oil pressure when cold at 7000 is 95# (70 degrees},It never goes this high because I don,t race it cold, except one to see how high it would go. When warm it goes 70# at 7000, How bad is this? I was thinking (I think once and a while) that I could make a "Blow off valve" for the outside of the engine. What you think Oldhead

I don't like it that high but 65 to 70 is fairly common unless you design everything for less, I have run between 48 and and 70 with no issues. one thing for sure is if it's to low you wont have to wonder because your bearings will tell you for sure.

swampbuggy wrote: ↑Sun Oct 29, 2017 8:10 pm Plovett, i agree 100 percent, i am a firm believer in preheating oil and then getting the oil to 200 deg. after starting before applying max. RPM, fanatical Mark !!

I agree with swampbuggy. The extreme pressure additives in the oil do not start to work until your oil is up to temperature so you will probably see excessive engine wear if you race on cold oil. The other thing I would be concerned about racing with 95lb oil pressure is blowing the o ring out of the oil filter. At the least that will be a big mess. At worst a blown up engine. Just my 2c.