fuzchunk

will a standard sbc hi volume oil pump work in an lt1 ? the lt1 has a 7 inch pan and a 3/4 pickup tube vs 5/8. if I use the 5/8 pickup tube will it work?

RamAir95TA

iTrader: (2)

You need a pickup tube with the right diameter for the oil pump. Also, HV oil pumps are unnecessary on 95% of builds. A standard volume/high pressure pump is all you need. I'd recommend the Melling Select 10554 (standard) OR the Melling Select 10552 (high volume/pressure, if you need it).

fuzchunk

if it comes with the pickup tube and driveshaft in a kit does it work in the lt1? what would be the dissadvantge to going hi volume?

96lt1m6

iTrader: (31)

You suck the pan dry

RamAir95TA

iTrader: (2)

There is a chance that during hard braking, maneuvering, and at WOT that the pan can run dry when used in conjunction with a stock capacity oil pan. Additionally, it takes more power to spin a high volume pump (due to the larger gears). This puts additional strain on the already fragile composite oil pump stub shaft.

Only use one if your builder recommends it.

hitmanws6

iTrader: (20)

My tuner told me the same thing when we were talking about my build. He said at WOT for an extended period of time would suck the pan dry. Keep in mind you will realistically need 70lbs of oil pressure at most and the 40 or so just cruising/20 or so idling is perfectly ok.

WS Sick

Shaft collar, the shaft itself is steel.

The HV pump uses around 1/2 more HP than a stock one, if the pressure springs are the same, if you have a higher pressure spring in your stock volume pump , it actually uses more hp than the HV pump with a standard spring.

As said do not use an HV pump with a stock capacity pan for engine life reasons.

brucer

you could also use a extra capacity vortec truck oilpan...

only time i use a hi volume hi pressure pump is when i can use atleast a 1qt extra capacity pan..
my bigblock truck runs 50psi at hot idle and hits 80psi from 4k rpm and up, i run a milodon 8qt pan.. i also use 2qt filters in the truck.. its built for street use and tolerances are in the mean..

quik95lt1

iTrader: (7)

absolutly i have sucked my pan dry before I have a hi volume std pressure melling.......a long third gear pull then baking off would result in a pressure drop from 60 to 20......of course im running 20/50 and revving alot but still 6 quarts my pan was sucked dry.....at 7qts its fine no matter what.....for what its worth


like i said above i did it.....i made a pull through 3rd gear on the street and then went into OD and when i backed off it was sucking air........also 70lbs i plently of oil pressure.....im running 60lbs at 8000rpm with no issues at all.

shbox

Just curious as to the source of the HP statements. The gears in an HV pump are much larger, so I would say that is where the additional drag is created. I mean, it's not going to pump more volume without larger gears.

WS Sick

The gears are 1/2 inch longer, the resistance of the oil on the output side of the pump is where the resistance comes, alot of that is blown back out by the releif valve.

If it took alot of power to turn a HV pump in 30 wt oil my cordless hand drill would have a hard time priming the motor. (and its rated at 1.5 hp)

http://www.mellingselectperformance....lume-pumps.pdf

brucer

i have always built gen1 sbc with hi-volume, high pressure pumps, with stock pans, but the stock pans are 1qt larger than the lt1 pans.. never had a problem with them...

i think the big problem with the lt1's are the composite drive gear and housing.. i think it deflects or twists, causes premature gear wear then it strips or breaks..

i thought the hi-volume/high pressure pump gears were 1.25 thick.. and standard volume was 1 inch..

fuzchunk

thanks I went with the stocker melling m155 3x the price for the blueprinted version did not seem worth it i mostly a dd .was also concerned about the composite drive gear

shbox

So, you are basing HP requirements by the ratings of a hand drill???

The myths and fables on that paper must not apply to the LT1, since both running the pan dry (not so common) and drive gear wear (more common) are real world concerns documented by lots of internet threads. I do agree that increased bearing clearances play a part in wanting an HV pump, but most people don't run big clearances and therefore don't need one.

WS Sick

what I am saying is that using an extra hp or 2 will not be noticed between the two pumps and first off cannot even be shown on a dyno, Oil pressure differences have been proven on a dyno, even with a stock volume pump.

WS Sick

I said this as well.