Oil weight and pressure

[tcone1@comcast.net]

Hello,

New to Fords...my last race car was 20+ years ago..and a 911 at that.

I've got a 347 stroker crate motor with roller rockers.

What weight oil should I be using?

Using 20w50 nets me about 70 psi. Is this too high?

Thanks,

Tim

[Matt Levine]

I'm no expert but 70psi seems a bit high. My FMP crate engine pumps about 50 lbs cold, and drops slightly when hot. That's with 10-30 cheap break-in oil. I'll use around 5-40 synthetic when I have a few miles on the motor. If I recall Porsche recommended something like 0-30 or 40 "Mobil 1" on the 2002 T. Turbo. I'd never heard of 0 weight viscosity.

[BostonBuster]

Good rule of thumb , use the lightest weight oil that will give you the oil pressure you need. Is that 70 psi constant throughout the RPM range or at a certain RPM ? Whats the range. Some motors need higher Oil Pressure and Vol to live. A small lock ford should be ok with 30 to 70.
Try 10-30W Valvoline Racing Oil and see what you get ?

[bossracer]

I think Fords like more pressure than others. The stock oiling system is not nearly as good as a Chevy, so you can't really compare what works in a Chevy and say that is what you are going to do in a Ford. Not that you said that you are, but many make that assumption or apply what an expert says not realizing they are speaking about a Cheby.

for many years I tried to run Mobil 1 in various weights. I was never able to sustain high enough pressure for long. I switched to Valvoline race oil (this is a race car, not a street car) and have had NO oil pressure woes. 60Wt oil equals about 60 PSI cold at start up. But going down the straight and shifting at 7500 RPM the oil pressure stays rock steady at 80 PSI.

440 hp Boss 302 engine, solid flat tappet cam, 12.5 compression.

I would rather give up a little horsepower by running a heavier weight oil than blow up my engine (again) by running too light an oil.

I'm afraid, Matty, you may be in for a suprise when you switch to 5-40 mobil 1. Keep an eye on the oil temp. As the temp goes up, your pressure will go down. it will go down real fast as you creep up on 250F in the pan. You will have almost no oil pressure above 280F in the pan. But the oil will look good

Dan

[80cid]

I was always told that 10psi per 1000rpm is a good rule to follow.

[DealsGapCobra]

70 psi is fine.

[hind sight]

70 psi at hot idle? Stock volume oil pump or a high volume pump? For a high volume high psi pump that would be about right. For a stock volume pump it would be high. Personally I would drop down to 10-40wt and then check pressure unless the builder specifiies 20-50wt.