Chevyguy358

iTrader: (4)

Ok I've heard multiple different opinions on wether I can run a HV oilpump with a stock pan. I have a 383 shortblock that I am assembling and I have purchased a melling m155hv oil pump for it. I have the 3/4 in inlet and matching pickup. Can I run this pump with my stock pan and if not what is the highest flow pump available that I could run. I supose I could buy a new pan however I would perfer not to spend $300 or so. let me know what you guys think.

98pontiacfirehawk

That is a old wise tale, the HV pump is only pumping 25 percent more flow than stock, if you are running the pan dry you most definitely have a problem with drain back(clog oil valley), the only pump you need to avoid is HV High Pressure pumps 60 psi up due to the heat build up.

Chevyguy358

iTrader: (4)

well this one is rated at 70psi...will that be an issue??

wrd1972

iTrader: (12)

This has been covered many times. Many have lost motors because they used the high volume pump an a standard pan. Do a search for the many opinions, the "dont do it's" outweigh the "do it's" by 3 to 1.

I would research it in depth.

Chevyguy358

iTrader: (4)

yea I've already thoughly seached the forum and realized there are many opinions on the subject thats why I posted this. I supose I should go with a standard volume pump. Just curious if anyone knows of a high pressure pump that is standard volume and if so what part number.

98pontiacfirehawk

I have the same pump you are talking about, the 70 psi is max out put warm will be 37 to 42 psi. As for the other post is Bull!! when I was in school a few years back we had to do this type tests, nothing happen, these were 5500 to 7200RPM'S tore the apart bearings check out within spec's. Like I sad, a HV pump is only 25 percent more flow, if the oil is not draining back there is a problem oil valley clog. If there were engines that spun bearing is due to something else, most likely rod bolt stretch not in tolerance. Yes, your pan will be fine. Like I sad, a wise tale.

fordeater

iTrader: (5)

dont use the HV, stock pumps are perfectly fine. also those series of castings from melling have a weak part about them and people were breaking them. but in short dont use the high volume, get a standard volume, standard pressure and be done with it.

fordeater

iTrader: (5)

and I used melling's 10554, its std pressure which is high pressure, std volume. and it is the select pump with the stronger casting.

speed_demon24

iTrader: (6)

Does your engine builder reccomend a HV pump? And like others have said the regular melling pumps are a weaker casting that are prone to breaking. I would return that pump and go with a melling select pump.

Chevyguy358

iTrader: (4)

yea the builder stated a hv pump would work fine though I dont know the clearances...I will prolly just go with the select melling

fordeater

iTrader: (5)

Man I really wouldnt go with a hv, I dont want you to hurt that motor. hv's put more strain on the oil drive, and they suck the 5qt dry. im sure alot of guys have gotten away with it but why take the chance?

Chevyguy358

iTrader: (4)

yea I just got off the phone with a rep from summit...it looks as though GM produces an oil pump that is high pressure standard volume that I will prolly go with...part number NAL12555884

kgkern01

iTrader: (10)

Melling also makes a 10% (instead of 25%) HV pump. I'm running that with the GM "white" spring. 80psi on cold start up and about 45-55 hot idle w/155k on the motor.

Lonnies Performance

iTrader: (16)

A high volume pump in an LT1 oil pan will have oil pressure problems due to poor baffling. Speaking from experience here..... This applies to the Vette & also F-body pans. I've went to the effort of swapping them back to std volume for a reason.

The std volume, high pressure is the way to go.

Relating experiences to other small blocks has nothing to do with the oil control issues of an LT1 oil pan. I've built over 100 small block Chevys & used many high volume pumps (even big block Chevy pumps in small blocks) with no problems.... until I ran into the LT1 pan design. A better baffled pan will cure the problem, but there is really no need to go high volume, which was more of an old school engine builder theory.

speed_demon24

iTrader: (6)

The gm pumps are the same as the cheap melling pumps. Just go with a melling select.

Chevyguy358

iTrader: (4)

If you could get me the item number on that pump I would be very interested since I was on the phone with the summit rep for 15 mins trying to find one.

Chevyguy358

iTrader: (4)

I checked on that pump and it turns out its for a gen I...

fordeater

iTrader: (5)

its the same pump as gen 1's becasue lt1s are the same as first gen sbc, I had the gm pump 12555884 and it is a cheaper pump, and it is 5/8 inlet not like the mellings which are 3/4. the 10554 is std volume std pressure, its in my car and I have perfect oil psi.

Chevyguy358

iTrader: (4)

kinda strange that summit doesn't recognize it as a pump for that application...but ill look into it. thanks

fordeater

iTrader: (5)

summit and jegs do not know very much about the lt1, I would not trust them with alot of things.