LT1MAN

iTrader: (6)

got my new motor in and running. but the most oil pressure we've been able to muster is 25lbs after repeated revs to 3000 rpms. it has a brand new high volume oil pump, and a brand new stock GM sending unit and a stock pan. and plenty of oil in it. what we have come up with is that with how much oil is being sucked through the new pump, the pickup must be too close to the bottom of the pan and its creating a "straw" or "scavenging" effect and not letting the pressure build up in the pan. solution being a deep sump pan, which is not exactly cheap, but a good investment. i just wanted some opinions before i bought one.

rob97ss

iTrader: (1)

The problem is not the pan but the HV pump,put a stock pump on,it will be fine.

FASTFATBOY

iTrader: (23)

How close is the pickup to the pan? Did you mock it up? Needs to be an inch (ish) What is the pressure hot at idle? Have you screwed a manual gauge in the block and checked it?


David

FASTFATBOY

iTrader: (23)

Explain that quote please.


David

smoknta

I have heard of people sucking the pan dry with a HV pump, but not at idle. I can suck mine dry in the quarter, unless it is very full. You said you have a new sending unit in the stock pan? The pressure sending unit is not in the pan.

LT1MAN

iTrader: (6)

i bought the motor brand new fully assembled. the engine builder put a high volume pump on it. the guys that put the motor in thought it would be a good idea to put a new sending unit on. and it currently has a stock pan. the sending unit is outside the pan right, runs along the drivers side?

the guy who put the motor in thinks the screen on the pickup is real close to the bottom of the pan, but was not sure. but we couldn't think of any other reason as to why it wasn't building enough pressure other than if it couldn't fill up under the screen as fast as it was being sucked through it.

LT1MAN

iTrader: (6)

so you see it pretty much the same way i do, but have a different solution. a stock pump would essentially be addressing the same problem. hmm, do you think a stock pump is enough for a 383?

plaf713

iTrader: (8)

dude, my oil pressure stays around 70 psi all the time, never goes under it

LT1MAN

iTrader: (6)

did he put the high volume pump on yours?

Dr. Teeth

iTrader: (4)

Put some thinner oil in it and try again. If it's better then that's you're problem. Sounds to me like either the sending unit is wrong, or there is a major bleed somewhere. I thought the port on the side of the pan was just to tell if there was oil at all, and not for pressure tho-?

plaf713

iTrader: (8)

so he says, so right now i am saying yes

FASTFATBOY

iTrader: (23)

The sending unit for oil pressure is on the rear of the intake on the back of the block.


D

LT1MAN

iTrader: (6)

think oil could make a 30 psi difference?

plaf713

iTrader: (8)

what are you going to do?

LT1MAN

iTrader: (6)

i think im going to get a pan because i want a windage tray anyway.

95greenZ

iTrader: (2)

From what I read you need a bigger pan with a HV pump. This is why I didn't go with a hv pump read plenty of horror stories about them.

I went with a high pressure melling and stock pan. I get 65-70 at startup and 45psi at hot idle. You might want to consider a high pressure pump too.

rob97ss

iTrader: (1)

From what i understand the HV pump will suck a stock pan dry,I have a stock pan,melling55 on my 383 with no problems at all.Great oil pressure

siniSSter

iTrader: (2)

I have a 383 application also with a stock pan. I noticed that it sucks the pan dry, with 5 qts of oil. I just added one more qt, and seem to do the trick.

Oil Pressure Levels - 70psi cold startup------40psi normal opertating temp

carzman5678

I built my 383 and I get about 65 cold start and 45 hot while driving and around 25 hot idle. I use a stock style pump and it doesnt have no problem with oiling. A maximum of 35 on a new engine doesnt sound to good to me. Might be a little too much clearance on thosse bearings.