What's Normal?

Greg Kulp · #1 (**permalink**) 09-24-2003, 07:08 PM

Ok folks, what's the "normal" range of oil pressure for a 302 with a standard volume/pressure oil pump? How about on an engine with less than 100 miles on it?

Thanks,

Greg

mstngjoe · #2 (**permalink**) 09-24-2003, 10:02 PM

If you're running bearing clearance up to .0025, you should be fine with about 10psi per 1k rpm.

What are you seeing?

NeedAntiVenom · #3 (**permalink**) 09-25-2003, 06:14 AM

Greg,

Oil temp at 180-190 degrees, 2500 RPM, around 65 PSI. Idle can vary a lot but somewhere in to 25-30 range. Normal rod and crank clearances are at 0.0025"

With cold oil you may see 80+ pressures on startup.

If you can't get your oil temp up - you might consider a bypass/thermostat for the oil cooler.

Jim

Greg Kulp · #4 (**permalink**) 09-25-2003, 06:45 AM

Thanks Jim and Joe. I am seeing 80+ at startup, and then 90-95+ at 3000rpm after running for 5-10 minutes. For now I am running w30 Pennzoil. I don't have the oil cooler plumbed yet, but guess I need to give the oil more time to warm up. Any thoughts?

Excaliber · #5 (**permalink**) 09-25-2003, 10:22 AM

I'm running 60-65 psi at full temp. 80 psi when cold. Even at idle I'm still doing 40-50 psi. 20-50 oil. This was/is a brand new right from the manufacturer 302 engine with about 20K miles on it. Not a rebuilt or crate motor.

Ernie

Dan Stryffeler · #6 (**permalink**) 09-25-2003, 02:33 PM

5W-30 Oil;

65lbs cold at idle (1000rpm) about 75lbs off idle.

45lbs warm at idle (900rpm) about 60lbs off idle.

- Dan

NeedAntiVenom · #7 (**permalink**) 09-25-2003, 04:11 PM

Greg,

You might want to consider using 10W30 or 10W40 instead of 30W. A thicker oil will give you more pressure but less flow, more flow will run the bearings cooler.

BTW, I have an oil cooler installed, but not hooked up. Joe Lapine (who built my 302) said it just wasn't needed except for track use. So far he has been right - without a cooler my oil has never gone over 190 degrees.

Jim

Greg Kulp · #8 (**permalink**) 09-25-2003, 05:27 PM

Ernie, Dan, Jim,

Thanks. Since I wanted to change oil soon anyway I think I'll give 10w-30 a try.

Jim, when I hook up the oil cooler I will use a thermostat. You are right about only needing it for track time, and I know oil that is too cold is not good.

Thanks,

Greg

Bob In Ct · #9 (**permalink**) 09-25-2003, 05:38 PM

Jim has it exactly right, pressure does not equal flow! I would consider a 5W-30 synthetic. Avoid the Fram filter.

Bob

Greg Kulp · #10 (**permalink**) 09-25-2003, 06:03 PM

Bob,

Yup, no Fram's on any of my cars. I stick with Motorcraft on my Ford's.

I will definately switch to a lighter multi-viscosity oil this weekend. I won't switch to synthetic yet as the engine still has less than 50 miles on it. After I have a few thousand miles on the engine I definately will switch to synthetic.

Thanks,

Greg

Greg Kulp · #11 (**permalink**) 10-26-2003, 11:59 AM

Well I tried switching to a lower visocity oil (5W-30) and that did not help. So I decided to tear of the oil pan and check the oil pump.

After comparing the installed pump with a brand new standard volume pump it turns out I had a high volume pump, not a standard volume as I assumed. The depth of the pump rotors were deeper than the standard volume pump (more surface area, hence more volume.)

Anyway... installed a standard volume pump and now my oil pressure is 60-65lbs off idle with cold oil at start-up. By the time the engine warms up and idles steady the pressure is 45lbs. After warm and revving to 5000rpm the pressure goes to 65lbs max.

Sounds good to me.

Greg