Clarification on Poor Oiling System

[Canyonero]

My machinist will go on and on about how much the 2.8L engines suck because of their poor oiling system. He acknowledges that the 3.4Ls don't seem to have that problem. I don't recall the specifics of our conversation though.

I'm thinking of rebuilding my 2.8 into a 3.1L and I'll have to be dealing with him. What exactly is he talking about?

[geoffinbc]

He doesn't know what he is talking about. Ask him what he says about the oil system in a 4.3L V6. If he says it is great then he has to think the 2.8L/3.1L/3.4L is great because it is IDENTICAL. Then ask him what he says about a Buick V6 oil system. That oil system is the shits.

He may think that the one large oil galley used to supply 1 lifter bank the cam and the crank is a poor design but it is actually very adequate. There was only a couple minor changes to the oil system prior to the introduction of the 3X00 and that is the switch to an all iron pump in favor of the early aluminum body pumps and the increase in pickup size for the 3.4L. Early small journal cranks were prone to failure but that was solved early on and your engine is not subject to that problem. The Introduction of the 3100 V6 saw the addition of a third oil galley that supplies oil to the crank and cam separate from the two lifter galleries.

Go ahead and build your motor. Just use a 3.4L pump and 4X4 pickup and you will never have an issue.

[candychevy87]

tell the mechanic to use a high volume pump and shut his mouth!

[geoffinbc]

Thats still not required and can often do more damage than good. Just use a new stock pump with a large pickup.

[Superdave]

Thats still not required and can often do more damage than good. Just use a new stock pump with a large pickup.

isn't it just the DOHC 3.4 that needs the high volume pump?

[geoffinbc]

I think it is the same larger pump that the 3.4L uses isn't it?

[Superdave]

i think i remember hearing that the LX9 uses a high volume pump but i didn't notice any difference in it VS the other ones i've seen...

[Canyonero]

I have a high volume pump in my Trooper 3.4L. There may not be any benefit over the stock pump, but I don't believe it does any harm.

[3100 MPFI]

only engines I have heard of needing the high volumn pump is the 3.4 DOHC, and the 3.1 TURBO (to help feed the Turbocharger).

I am suprised that Lorenzo (GPSE3400) has not chimed in yet. He put the high volumn oil pump in his 3400 and that ended up killing his engine. It was talking too much oil out of the pan and caused him to mess up his bearings (I think the 3400 started knocking). The high volumn oil pump was too much for an engine that is fine without it.

[geoffinbc]

Exactly. Most engines (from Chevy at least) do not need any increase in oil volume.

[gpse3400]

the 3.4 TDC pump is bigger than the pushrod HVHP(turbo) pump. It is different in that regard plus they weld the pick up the pump body.

From what I know the GEN 3 and 3.4 TDC has a similar oiling system to an SBC

[gpse3400]

I'm HERE!!!!

I can't say for sure what really happend to that engine but I know I put an HV HP pump into my old '94 Z28 and I sucked the pan dry. Saw it in the gauge.