ptindall

For a track car with an LS6 using the stock wet sump batwing oil pan, is it a good idea to use a high volume pump or a bad one? I am worried about increasing the risk of sucking air in long high G corners by drawing oil out of the pan at a higher rate. What is everyone else doing? Is my fear ungrounded and I should get the higher rate pump or should I get a stock pump? Thanks.

z28lt1

Can't speak to an LS6, but in my previous car, my engine builder said to go with a high pressure but standard volume, for the reasons you mentioned. But he also built the motor, so knew what clearances and such would be like. I've had many also recommend standard volume/pressure on basically stock motors.

EDIT: For reference, this was in an LT4 motor (90s version, not todays).

STANG KILLA SS

Definatly go High pressure not high volume. you will love it.
high volume can easily suck the standard capasity LS6 pan dry.

im running the Melling unit on my latest motor build. http://texas-speed.com/p-108-melling...s-engines.aspx

seeing 60-65 psi.

aaronc7

I also got the standard volume, high pressure Melling (10295). My reasoning for the high pressure model was to help offset the pressure drop I would get with an oil cooler. IIRC I was getting around 45-50 psi WOT at around 240-245 oil temps last time out. 2003 Z06 w/ LS6. Lots of guys running the high volume model, the sucking the pan dry thing seems like a myth to me. I just have a more or less stock motor, so I figured I would get something that was more or less a stock pump.

ptindall

Thanks for the replies. I'm having a hard time understanding how the pump can deliver higher pressure with the same volume. As far as I know, the only way to do that would be to make most restrictive part of the system be more restrictive. I would think would be the engine bearings themselves. Can someone explain it?

aaronc7

For a given engine, pressure = flow more or less. Think of pressure as a measure of resistance...the more oil flow, the higher the pressure/more resistance.

the standard/high volume naming convention really indicates the size of the actual pump/gear... if you look at the high volume pumps, they are physically larger. High pressure naming just means it has a stiffer bypass spring.

Standard volume/high pressure pump should be just like stock, but it will allow a higher max pressure at high rpms. For my oil cooler setup, I knew it had a pretty significant pressure loss at high rpm/high flow conditions. So basically I only wanted extra oil pressure/flow in that high rpm scenario- so that pump made the most sense to me.

High volume pump should give you more flow and pressure under ALL conditions. I think the mindset of more/bigger is always better is what leads people to get this pump oftentimes. Will it work...sure, is it necessary, probably not. I saw some post from Melling, saying they did not recommend the high volume pumps for stock/never opened engines.

FWIW I saw a 10 psi jump in oil pressure going from stock GM to the 10295 standard volume high pressure pump across the board, even at idle.

ptindall

Thank you. That makes sense.

z06801

How about on a dry sump using internal pump for pressure? I have ARE with a 3 gallon tank. Would like to see a bit more oil pressure. 434ci ls2.

Horseshow Manager

My builder XP Racing in OKC had checked with Melling before we purchased pump. Told in no uncertain terms to ONLY go High Pressure on a wet sump system. High Pressure AND Hi Volume would have to be on a dry sump system. Otherwise you evacuate the crankcase faster than it is returned.