PLRX

I need to buy an oil pump for my LT4. Due to the fact I'll be using the stock oil pan I can't use a high volume pump.

1. http://www.summitracing.com/parts/NAL-93442037/
This one is a high volume, standard pressure

2. http://www.summitracing.com/parts/NAL-12555884/
This one is standard volume, high pressure (60-70 psi)

The dealer tells me that #1 is the LT4 pump.

So which one is the one I can use that will not starve the pan or send too much oil pressure and perhaps break something?

Both pumps come with out the oil screen but Melling sells it.

GM no longer makes the oil screen

383tpimachine

is there a melling full replacement?

I have an L98 so just used a stock GM unit
but with my next build will buy a melling system

PLRX

I found this one. It's also a high volume

http://www.summitracing.com/parts/MEL-M155HV/

2012 coupe

I just put one of these pumps in my 427 LT-1 rebuild. Gives me about 20 added lbs pressure over the stock one.

ultraviolet70

Go to Lingenfelter and get the basic Melling M155, they also have the pick-up, a HD drive shaft and the high pressure spring to go with it it only adds about 10 psi which is not overkill this package is more than adequate for all but the most serious builds, and it'll cost you less than $80 for all of ti with shipping.

Here's a link to the pump, and the three other components I suggested are listed right below it.

http://www.lingenfelter.com/mm5/merc...egory_Code=C54

ZD1

what drives an LT1/4 oil pump? camshaft via oil pump shft? magic

one more thing driven off the cam gear?

blkzr1

hi, i used the m155 in my 1995 lt1 383 and am very happy with it. the pump produced around 70 psi cold at idle and 40 when warmed up. at 5700rpm i have about 62 psi hot. i took mine apart and brought the clearence between the gear face and end plate to .002 inch and cleaned up all of the passages in the pump. i also opened up the rear main cap oil passage hole to the same size as the pump hole. if you compare the pump passage to the cap passage, you will notice an area that needs cleaning up. i have a very thick piece of true flat glass that i placed some 400 grit wet/dry paper on to true up the end plate and reduce the clearence on the main case. see ya

Weav's Vet

Get the Melling shaft and the GM white spring. Plenty of oil pressure with these. No need for a high pressure pump.

Muffin

To add fuel to the fire, take a look at Rock Auto.

BrianCunningham

There's a shaft in lue of a distributor to drive it.
http://www.shbox.com/ci/cam_removal.html

shadowskill

Last time I went to the track I had almost none pressure on the last heat; time to rebuild (cam, RRs, timing chain, etc). I want to be on the safe side. If I wanted to use a canton racing pan and like to keep the oil pressure on the healthy safe side, what pump do you guys would recommend?

I wanted any of those two (GM), but don't know of the drawbacks from #1 (high volume) or #2 (high pressure).

mtwoolford

melling 10551, CNC machined, phosphate coated; high volume; high pressure spring installed; and yes, high volume pumps fit in Vette pans; clearances are tight, but they do fit.

GREGGPENN

Or the 10552 which is 10% HV (vs 30%). TPIS recommends this one.

No Go

Why does everyone try to reinvent the wheel?

Why not just a stock LT4 pump from Chevy? I'm surprised that the 'pickup' is not available...

PLRX

unsubscribed-

mtwoolford

why not the stock LT4 oil pump; you mean besides it being way over priced?

in the nineties GM began to worship at the altar of the false god Fuel Economy. And one of the first things they sacrificed was the oiling system.

they lowered the oil pressures, began running low viscosity oils with the consistency of tap water and SOMEHOW convinced its customers that 10 psi oil pressure per 1,000 rpm was acceptable.

read the threads in this forum and all the problems with cam lobe failures and spun rod and crank bearings. theres gotta be an inadequate lubrication issue.

plus, my 1996 C4 uses the same exact flat windage tray as the factory installed in my 1961 corvette. Does GM think its customers are gullible enough to believe that in the intervening 35 years there was no advance in the art and science of windage and oil control ?

why not a stock LT4 oil pump indeed.

larry00

You don't want to fight the leaks from a high pressure oil pump !
Higher volume than stock will suffice !

I had to remove distributor for years just to add oil cause I had to run Valve covers with no openings to leak !
Something to be said about Dry Sump systems !

No Go

My point is the factory in many instances knows more than vast majority of 'us'.

Yes thin oils are mileage makers, but they also are HP makers.

SBC oiling system are almost bulletproof except for those that turn serious rpms or do something very nonstandard-read all the hot rod manuals by Smokey Yunick, etc.

I stock LT4 pump (ok maybe more then Summit at @ $62, but we are talking a twenty dollar bill additional for the heart of your oil system?) run 5W-30 Mobil 1 synthetic with oil temps as high as 300 degrees on the road courses...drive it daily and shift it at ~7200 rpm. 38,000 miles with no oil failures.

I also run a Canton road racing pan along with my nearly R comp tires...

Lobe failure would not be related to a HV or HP pump-splash oiling. Failed bearings is more than likely related to draining the stock oil pan due to lack of oil sump or HV pump draining it. Even stock LT4 has experienced engine failures due to insufficient oil capacity and high lateral accelerations with OEM components-I ran for years with an extra quart to fight this with no ill effects.

Windage tray...got me there, but I think it only mitigates the issues, not eliminates it.

I wonder if people would be better off putting some money toward a road racing pan and pickup on an OEM pump...

PLRX: I'm not sure what is "WTF" about this subject.

Good Luck.

PLRX

The problem was taken care of at the PM level.

Ultraviolet helped out, looks like now we have to post a closing post if you start the thread...

No Go

PLRX: I now realize this thread is quite dated, but typically folks do like to know the end result.

Glad Ultraviolet was able to help out...as apparently none of the other 12 posters provided any assistance? Bummer.