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Oil pump 383hp

pjm8047

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If i needed to replace my oil pump on my 71 rr 383 what would i need? A high volume or high pressure pump? Ive heard melling makes good pumps.
 
I have had the standard one on my dum 68 all the years I have owned it, and it has no problem getting url everywhere. Actually I had a high volume for a few months but took it off because I thought it was too much. I don't race or anything, I just rumble around.
 
more oil volume is more impotent then p.s.i oil is what cools the engine so more is better. with a hi volume pump p.s.i will go up mine runs 80 p.s.i. cold and up to temp 40 at idle in gear.
 
I was convinced by my engine builder to use a regular oil pump unless I had a deep oil pan. He said the high volume pumps can empty out a stock pan too quick.
 
I was convinced by my engine builder to use a regular oil pump unless I had a deep oil pan. He said the high volume pumps can empty out a stock pan too quick.
Been using a melling hv pump since the rebuild with a 402 pan. Never had any pressure decreases no matter what I did. Just be sure the level is always full.
 
Didn’t the hp big blocks come factory with a high pressure pump?
 
If you have low oil pressure, switching to the High Volume will help.
The High volume pump is thicker than a standard pump, so it needs longer oil pump bolts.
I forgot the bolt lengths, but usually the three shorter ones are a bit too long, and can bottom out in the block before clamping the pump.
Another tip is to make sure the O-ring on the housing that goes into the block is clean with a bit of oil on it. That O-Ring is on the suction side of the pump, so if it leaks, the pump will suck air, not oil.
It is also a good idea to disassemble the pump, and clean it real good before installing it. last one I had there were metal shavings right inside the intake port of the pump.
 
I was convinced by my engine builder to use a regular oil pump unless I had a deep oil pan. He said the high volume pumps can empty out a stock pan too quick.


he is right at high r.p.m it can but a 6 quart pan and windage tray can fix that.
 
Didn’t the hp big blocks come factory with a high pressure pump?


p.s.i is set but the re-leaf spring and valve for by-pass. so no you would remove the plug and add a washer to up p.s.i if you went racing right after you bought it.
 
I like to make sure the rotor face has no less than .002" clearance too.
 
I like to make sure the rotor face has no less than .002" clearance too.


most dont know there are 2 different length rotors for mopar . some of the f--d rotor's were different length and interchanged with mopar
 
most dont know there are 2 different length rotors for mopar . some of the f--d rotor's were different length and interchanged with mopar
Are you trying to say 'Ford'? lol. Didn't know about that.....
 
if you look in the mopar engine book it will tell you how to measure all the oil pump clearances.and the specks
 
If you have low oil pressure, switching to the High Volume will help.
The High volume pump is thicker than a standard pump, so it needs longer oil pump bolts.
I forgot the bolt lengths, but usually the three shorter ones are a bit too long, and can bottom out in the block before clamping the pump.
Another tip is to make sure the O-ring on the housing that goes into the block is clean with a bit of oil on it. That O-Ring is on the suction side of the pump, so if it leaks, the pump will suck air, not oil.
It is also a good idea to disassemble the pump, and clean it real good before installing it. last one I had there were metal shavings right inside the intake port of the pump.
I second this. I always deburr and clean new oil pumps. Humans assembled them.
Mike
 
A stock pump is good if you check the internal clearances. Melling standard is an excellent choice for daily driver, maybe not max performance use. Then the Hi volume if your bearings need that.
 
Never used anything but a high volume pumps in what ever I've built, haven't lost one yet. Of course my engines don't run it 90 knots all daylong either....so there's that. Generally stock engines only suck up about half of what's in the pan at one time, a HV isn't going to move that much more oil since we're talking about high volume not high pressure. Think about it, if you were to add up all the passages and relate them to liquid volume, the passages only have about a quart, quart and a half max maybe at one time under pressure. With that said, and the residual pooling in the heads/lifter valleys, the pan shouldn't be lower than half of the oil capacity in the oil pan under load.
Some engines are bad about oil pooling in the heads/valleys (Old's BB are notorious). Mopars are pretty good about oil draining back in to the pan in my experience.
So all in all I would opt for the high volume and stay away from high pressure pumps, they tend to invent new leaks....IMO
 
A HV pump is as useless as ******* on a bull if the oil has nowhere to go - like looser bearing clearances, etc. Putting a HV pump where a standard will suffice has a couple negative affects. Since the added volume has nowhere to go: 1) it puts more load on the engine, cam gear, oil drive shaft, etc. 2) since more volume with no additional clearances means more pressure, it will run more oil through the bypass. This generates more heat in the oil.
 
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