High Pressure Oil Pump??

[dmfconsult]

I've decided to change my old banged up oil pan ( 302 double hump). The new pan came with a pick-up which I will install and since I do not have a history of the engine (mid to upper 1980's with a cam, upgraded valve springs, 650 holley etc.), I think I will replace the oil pump and shaft while I have the pan off.

The Question;
Would I be better off for any reason to install a high pressure oil pump? A high volume oil pump? Or a manufacturer spec. oil pump?

[Hal Copple]

your going to get lots of opinions on this. Your oil pump question is something everyone who builds an engine has to deal with.

Oil pressure is dependant on oil flow volume, and flow resistance. The latter is the most influental. It depends on oil viscosity, temp, and engine clearances.

engines need "enough" oil pressure to safely operate, but more than that is not necessarily better, and causes its own set of issues. Ford specifies 40# at hot 2000RPM, as a mininum.

To be succint, if you had reasonable oil pressure before, then i would suggest just replacing your oil pump with a stock Melling. If you have generous engine clearances, or run in a really hot environment, then a high volume pump may be indicted. Remember, if you have loose clearances, and your pump is pumping all the voume it can, changing the relief pressure spring will not increase your pressure.

You can of course tweak your pressure a few pounds with a higher viscosity oil, and run a high quailty low restriction oil filter, and avoid 90 degree oil line turns.

It seems to my observation that Stroked Windsors run lower pressures than the 302 motors, i think because of the longer rod stroke.

Don't worry much about your hot idle oil pressure, a no-load low rpm motor does not need much more than 15-20 psi to safely idle.

In summary, i would replace your pump with a stock pump, and if you run 45-50 psi hot at 2000 rpm, you are fine.

[bmalone]

Hal makes a lot of good points and is right about getting numerous opinions on this subject.

I think the real question is High Volume or Stock. Looser clearances and/or race motor might dictate HV. Closer to stock, maybe stock-type pump.

I do not believe you want a High Pressure pump. They are known to "wash" the bearing surface and actually lubricate less.

[fxbill]

Another reason you might consider for using a standard pump.....High volume pumps put an enormous amount of strain on the distributor gear. I ate up three new hardened gears within a few thousand miles using a high volume pump. On recommendation from a good racing friend who has a vast knowledge of small blocks ( Ben Alameda) I changed back to a standard pump.....no more problems...