95maroz28

iTrader: (21)

The ls1 346 oil pump is the same as the 4.8-6.0 engines and is the oil pump the same as the later 08 tahoe hybrid 6.0? From 97 forward how long did they use the ls1 346 oil pump and on what engines and when did it change over to a newer style pump? ls2 ls3?

G Atsma

All Gen III and IV pumps interchange.
The only different ones were for AFM/DOD and VVT which are higher volume for those applications only, and the variable displacement one used in hybrid drivetrains.
Otherwise all the std. volume pumps are the same.

95maroz28

iTrader: (21)

Do you know what the tahoe 6.0 2008 hybrid pump is if its the high volume or same ls1 346 oil pump? May i ask did the ls3 still use the standard ls1 oil pump or a high volume?

QwkTrip

iTrader: (23)

What is it that you want to do? Maybe start with that question instead so you get better answers.

You can kind of get a feel for variation of oil pumps by looking at Melling's variety of stock replacement offerings.

G Atsma

The LZ1 hybrid engine uses a variable displacement pump, unique among LS pumps.
The LS3 uses the standard volume pump. There is no specific LS1 oil pump.

LilJayV10

iTrader: (39)

Engine Masters just did an episode on LS oil pumps. It was actually really really good I learned that you shouldn't put a Gen 4 pump on a Gen 3 engine. Wow.

G Atsma

I think that depends on the Gen IV pump in question.
Any of the standard volume pumps should be fine, as they are about identical to Gen III pumps, BUT the higher volume or variable displacement pumps might not.

LilJayV10

iTrader: (39)

They were using some badass Melling pump for the Gen 4 w/ DOD and AFM. 160psi of oil pressure at the top of the run.

They also used the Melling 10295(maybe the 10296, I was half asleep when I watched it) I think it had a little over 100psi

The stock style pump was 70ish psi.

It was really interesting to see the power difference between the three pumps.

G Atsma

Yeah, the DOD/AFM pumps have higher volume. So is the Melling 10296.
Stock style pumps are the same for both Gen III and IV.

Che70velle

iTrader: (6)

Oil pressure is dictated by, and is a measurement of resistance, which is bearing clearances. You could effectively get whatever number you desire with a stiff enough bypass spring, very tight bearing clearances, and an oil that stays viscous at temp. And of course enough pump to push volume, which most LS pumps will do with ease.

Polyalphaolefin

A stock replacement Gen III Melling M295 pump will flow enough oil to do most anything you'd want to do with a wet sump engine. By the time the high volume pump is actually needed, you're likely ready (and better off) to go dry sump anyway.

The results of the EM episode are about inline with what I've seen as well.

wormw00d

Hello, im new to the ls1 forums, im currently doing a mild build on my 2002 ls1 and a local machine shop guy told me to use an oil pump from a 2008 chevy tahoe 6.2 melling part #M365. im reading here that that isnt a good idea?

G Atsma

Read this thread. The stock-size pump is very adequate for most relatively stock LS engines

grinder11

iTrader: (1)

Stock is fine. The Melling 10296, which I run due to piston oil squirters, is a good oil pump, especially if you leave the standard relief valve spring in it. But stock is fine for just about any build except DOD, piston oilers, etc.....

slowride

iTrader: (3)

what squirters do you run and bearing clearance? Curious what pressure range you are seeing thanks.