tech@WS6store

iTrader: (2)

There are so many threads over "which oil pump" etc, that I think a little actual info on the pump differences would come in handy.
There are 7 (so far) ls oil pumps for ls engines. They are all wet sump so that makes classification easy and universal use for gen3 on4.

M295 - std pressure std volume rotor thickness .420"
10295 - 10psi higher pressure std volume rotor thickness .420" hardcoat anodized includes std pressure spring also
M295HV - 10psi higher pressure 18% more volume rotor thickness .499 includes std pressure spring
10296 - 10psi higher pressure 18% more volume rotor thickness .499 hardcoat anodized includes std pressure spring
M355 - 25psi higher pressure 33% more volume rotor thickness .507 does not include std pressure spring
10355 - 25psi higher pressure 33% more volume rotor thickness .507 hardcoat anodized includes std pressure spring
M365 - 15psi higher pressure 33% more volume rotor thickness .507 does not include std pressure spring

The M355 is std equipment for vvt and afm engines. M365 is std equipment for vvt, afm, and hybrid engines.
I will be updating this thread with block and body measurements as well later.

Hopefully that is better info to make a good decision.

G Atsma

Good info! Clears up some confusion for many.

SSSTANG#1

iTrader: (14)

Thanks for the info.

455GTO

iTrader: (18)

Great info

Might also be helpful to include your pump in the list in addition to which pump would benefit certain applications best.

tech@WS6store

iTrader: (2)

Right! I am porting 15 more as we speak so ill have the info from that also.
These 2 threads will be updated when i get more info so it will be as complete as the community needs.

Our pumps come with a std pressure spring but can be shimmed to make 10 more psi.

slow7denali

Sooo this means that when I rebuilt my L92 and went back with a melling 10295, I went backwards to a smaller pump? I did delete VVT and it didn't have AFM from the start, so that's confusing. I feel like my pressures are a bit low, 28@hot idle and it never gets above 45@ hot wot.

tech@WS6store

iTrader: (2)

You have no need for the extra volume from a stock style high volume or 10296 10355 pump. Not ALL vvt pumps are high volume. Only some. Mostly ones that operate vvt and afm although o believe all afm engines have the high volume.
Going to a 10295 was a good idea. Plugging the dod towers physically is a REALLY good idea.

slow7denali

SO the oil pressure I'm seeing is no problem? I thought rule of thumb was 10psi per 1000rpm, and I'm only seeing 45 at 5-6000... I plan to add boost later, that's why I'm just a little bit concerned. The oil clearance on my cam bearings is .006 so that's a little wide, they recommend something like .0025-.005. Those are numbers we found after we had the motor together and back in the truck.

slow7denali

DOD towers are plugged with 1/8" pipe plugs and red Loctite...

tech@WS6store

iTrader: (2)

This has been argued before but that rule of thumb seems like an internet myth really. GM spec is .0009 to .0038 cam bearing to cam journal clearance. Thats for all gm engines. Any more than that is WAY excessive wear or cam issues. That would be the source of your low oil pressure. Adding a high volume pump only bandaids that issue if it helps. The wear can likely continue.
Gm min spec is 25psi at 1k 35psi at 2k and 38psi at 3k. That is def not 10psi per 1k. if that were so an engine at 800rpm would have a "min spec" of 8psi. Seems off to me.
I would like to see 40 psi cold and high 20s to 30psi warm at least if it were my engine.

tech@WS6store

iTrader: (2)

Did you plug the oil pan bypass?

slow7denali

Cold pressure is up around 50 and hot idle is 20-25. The cam and cam bearings are brand new, but I wasn't real sure which bearings I needed, therefore the excessive clearance. Couldn't get a straight answer from anybody at the time as to what bearings I needed. I guess the right thing to do would be pull the engine and swap them out.

No the pan bypass has not been plugged.

tech@WS6store

iTrader: (2)

Plug pan bypass and make sure the screen in back under oil pressure sensor is removed.
That will help i bet.
You need the gen4 ch23 or ch23p durabond bearings. Idk why there was any mixup on that.

slow7denali

I will try those two things and see if it helps. I'm pretty sure I have the CH23s but not positive. The cam is the right diameter so I dunno what is wrong.

Thanks for your time sir!

mark aubele

I have the stock AFM/DOD/VVT pump. 6.2 from an Escalade. Going into a '97 M3, will see a ton of high rpm use. Should I put a stock spring in it or run the pump as is? Or is there another pump I should run?

tech@WS6store

iTrader: (2)

You should use the melling 10295. You wont need high volume at all.

clinebarger

How would the by-pass effect oil pressure?

Only AFM valley covers have the screen.

tech@WS6store

iTrader: (2)

The oil filter for the newer pans have a built in bypass plus the pan has a bypass also so it can cause a short circuit issue. Gm has a tsb out about the bypass also. It can agitate pcv and oil consumption issues so they have a part number for a "splash guard" that fits over the bypass plug to keep it from shootin oil ***** nilly onto internal engine parts.
Plugging it can fix those issues.

clinebarger

Your speaking of the AFM Pressure Relief Valve, It doesn't start to creep open 'til 55 PSI. I have never seen the PRV cause low idle oil pressure. Debris getting lodged in it is a possibility I guess.....But, it's on the "clean" side of the filter so that's probably why they don't give many issues.

Oil pan removal is required to plug the PRV.

tech@WS6store

iTrader: (2)

I have seen them cause issues. Esp on LSA engines. Why have a double redundancy of oil filter bypass and pan bypass plus the added GM admitted issue of the pan bypass?
I have perosnally seen oil pressure go up by just changing that out on afm/dod deletes along with plugging the towers.