Originally Posted by Polyalphaolefin

70 psi is plenty.

Originally Posted by G Atsma

Poly, for a stock non-VVT, non-DOD/AFM engine, is anything more than a standard volume, standard pressure pump ever needed, or desired?

Originally Posted by Polyalphaolefin

It depends on the engine. For a street engine turning <7500 rpm with standard .002-.003" clearances, there's no reason to use a HV pump.

Originally Posted by Tony @ Mamo Motorsports

Scott

The 296 is actually only high volume....however while it comes with a standard pressure spring installed, it also comes with an optional red high pressure spring in a small parts bag that a customer could install.

My opinion on this situation is you don't really want pressure......you want volume.

"Standard" pressure is more than enough.....higher peak pressures drive the pump harder, costs you a little more power to drive it harder, and sprays engine oil from the bearings all over your cylinders giving your oil rings a much harder time of clearing the cylinder walls. Also more oil spraying in the crankcase and everywhere else creates more windage issues as well (and more drainback from the top end). There is just alot of excess oil and that will cost you a little power. One of the reasons a dry sump engine makes more power is the engine has less oil flying everywhere.

I see no need to have more than standard pressure especially with thinner higher quality synthetic oils and all the pumps I port and send to my customers are usually high volume but they always ship from me with the standard pressure spring installed (blue in color).

That said at lower engine speeds a higher volume pump will create more pressure (idle and low RPM cruising) because at lower speeds the pump isn't moving as much oil so in this situation volume dictates the pressure created. At much higher engine speeds the pump is moving ALOT of oil and creating more pressure so the bypass valve opens up capping the peak pressure of the pump.

The stouter red spring supplied by Melling (and installed from them in their higher pressure model pumps) is stiffer and it delays the opening of the internal bypass creating higher peak pressure (not lower RPM pressure) but I see very little benefit in that situation for all the reasons stated

Im sure you will get other opinions out there but that's mine.....LOL

Hope this helps

-Tony

Originally Posted by Polyalphaolefin

This is correct though the same can happen with higher volume through wider clearances. The issue I look for the most with high oil pressure >70 psi is aeration. The capacity of entrained air in the oil increases exponentially as pressure increases. There's been cases of bearing cavitation due to excessive aeration 80-90 psi oil pressure.

Originally Posted by theunderlord

hey Tony, love all the talk about oil pumps, this thread is amazingly informative! I clicked on the link in your signature, but your online store only sells throttle bodies? Maybe I missed something.

Originally Posted by G Atsma

Thank you. What about high pressure (which just means a harder relief spring)?

Originally Posted by Polyalphaolefin

It depends on the engine. For a street engine turning <7500 rpm with standard .002-.003" clearances, there's no reason to use a HV pump.

Originally Posted by Polyalphaolefin

(A high pressure pump is..) a solution looking for a problem. No use for them.

Originally Posted by 02EBC5Z06

I do have the ported Hubbard high volume. Can't recall the difference of that versus stock. The 296 is high pressure/high volume right?

Originally Posted by Tony @ Mamo Motorsports

No.....its actually me missing something.....LOL (the TIME to properly update my website.....LOL

Just shoot me an email or a PM and I will get you sorted out.

I carry standard volume ported pumps.....ported high volume pumps (aka 296 style pumps) and ported BIG dog pumps (LSA /ZR1 style pumps meant to carry factory engines that come with oil squirters / AFM/DOD).

The last style I mention, the "BIG DOG" wet sump pumps aka the GM LSA pump or Melling M365/10355 has an even thicker gerotor than the 296 pumps (a 296 nets an 18% increase in volume)....the big dog's bump the volume about 33% (both of these number without the porting factored in and that makes a solid improvement). I only recommend the largest pumps for engines that either have piston squirters or AFM/DOD, and axle oiling lifters (or for an engine simply built too loose that really needs the help in the lower RPM ranges). Once again I ship that big pump with a lower pressure bypass spring so as soon as the RPM's get up and that pump starts moving a bunch of oil it will cap out around the same 55 - 60 PSI range I have discussed by internally bypassing oil through the pump when the spring opens the bypass valve.

The 296 is usually adequate if clearances are set properly even with the axle oiling lifters. Stock engines with tight clearances, no squirters and no axle oiling lifters I usually send folks a ported standard volume pump and they still see some gains in lower RPM PSI from the increase the porting helps with.

Call or email me if you want to discuss further or purchase one from me

Regards,
Tony