High volume or high pressure?

satanas

Member
Dec 16, 2005
156
3
19
Arizona
I have my engine out and I have a question, Should I replace my oil pump its the original oil pump.whats a good oil pump?I hear melling has good pumps. Not sure what the difference between the high volume and high pressure.What the pros and cons. i have a 7 qt oil pan from canton.
 
The HV pump will wear out the cam gear faster, I wouldnt use it on a street car, its good for a race engine that gets rebuilt often.

Plus you have a 7qt pan so you shouldnt have to worry about the pan drying out at higher RPM.
 
The HV pump will wear out the cam gear faster, I wouldnt use it on a street car, its good for a race engine that gets rebuilt often.

Plus you have a 7qt pan so you shouldnt have to worry about the pan drying out at higher RPM.
Thanks LiquidGt. I guess I'll save me some money on the pump.I''ll get the stock replacement.
 
i have always ran the high volume pumps on all my cars without a problem... i think its just a matter of personal preference...if i was going to install one on a forced induction application i would deff use the high volume because the charger or turbo is stealing oil flow from the engine to lubricate itself..

jim
 
^I'm not the foremost expert on superchargers, but a HV oil pump could suck the oil pan dry at prolonged high RPM. Then the supercharger trys to pump its own oil out the dry pan... and then you know.

But you have a 7 qt pan and not the stock one, so its less likely that would happen. (With HV or standard volume) I just dont like the cam / distributor gear wear idea.


Here's is an article in 5.0 Mustang on page 124. They're putting together a Griggs road course engine.
"A Melling M68 standard-volume, standard pressure oil pump is used because the high volume pump chews up the cam gear and distributor. With the rpm and bearing clearances in an Al engine, more oiling isn't necessary. If extra coolers, lines, and fittings (for the coolers) are on the chassis, then Griggs would use a standard-pressure high volume pump"
 
^I'm not the foremost expert on superchargers, but a HV oil pump could suck the oil pan dry at prolonged high RPM. Then the supercharger trys to pump its own oil out the dry pan... and then you know.

But you have a 7 qt pan and not the stock one, so its less likely that would happen. (With HV or standard volume) I just dont like the cam / distributor gear wear idea.


Here's is an article in 5.0 Mustang on page 124. They're putting together a Griggs road course engine.

ive always run my high volume pumps with a stock sump pan and never had problems with sucking dry...id have to find out the exact specs, but i would be willing to believe that the melling high volume pumps dont pump insanely more than the regulars which is why you can probably get away with it... id be curious to see exactly how much flow it would require and how long of a runtime you would need to actually wear out the cam gear with oil?
 
I saw the blower in your sig when I recommended the standard pump. There is plenty of additional capacity in the stock pump to support the blower. I would imagine the oil needs of the blower are along the lines of the needs of a couple of rocker arms. Anyway, did the blower manufacturer recommend anything but the stock pump?
 
I saw the blower in your sig when I recommended the standard pump. There is plenty of additional capacity in the stock pump to support the blower. I would imagine the oil needs of the blower are along the lines of the needs of a couple of rocker arms. Anyway, did the blower manufacturer recommend anything but the stock pump?
no they didn't say anything about oilpump.
 
I've always ran high volume pumps as added protection in any motor i've rebuilt-freshened. If I was running a motor with loose bearing clearances (race, hi rpm, rebuilt yearly) I'd run a high pressure/high volume pump. But for a mild race/street car it'd be a high volume, esp. with forced induction oil needs.