Oil Pump Question

[Taylorman]

Does anyone have any knowledge about blueprinted oil pumps vs. stock pumps. My oil pressure is a little on the low side. I need to pull my motor before summer to fix an oil leak. While its out, I thinking about replacing my oil pump with one that has been blueprinted. I have heard that blueprinting a pump will dramatically improve oil pressure. The article that was written about HB's engine made metion of this. It said that Dave always blueprints the pumps that he puts in his engines. He said it could make the difference of 15 stock or 40psi blueprinted at idle.

[1tricky1]

I think you would be safe going with a high volume oil pump. From what I've heard, Mellings makes one of the better high volume oil pumps. They are especially needed if you have a 10qt oil pan. Personally I think any performance jet boat should have an oversized oil pan and a high volume oil pump. Even at cruising speed we are always turning more rpm's than in an auto application necessitating more controlled oil temps and pressure. Good luck!!

[Taylorman]

Thats what i have, a Melling HV with an 8 qt Moroso pan.

[1tricky1]

I believe that pump should be putting out 30-40psi at idle and about 60 at cruising. Not sure, but you might have some bearing clearance issues or other clearance issues within the motor. Oil pick up to pan clearance is also critical. Good luck with your diagnosis.

[matt1]

UH OH!!!!:eek: :eek: :eek: :eek:

[Taylorman]

Originally posted by matt1
UH OH!!!!:eek: :eek: :eek: :eek:
UH OH what. You knew I plan on doing this. Or is that UH OH something you found on your boat?

[Duane HTP]

I recommend staying away from the High Volume pumps. The standard ones pump enough oil, especially at high rpm, the HV ones have a tendency to drain the pan to easily. What you need is more pressure. I always put in the blue HP spring that is available from Melling, or if I can not find one, Pull the bypass spring pin, add a .060" washer behind it. That will give you the pressure you'd like to see without draining the pan. Just my .02.

[Taylorman]

How does a pump put out more pressure given the same volume. Not disagreeing, im trying to figure this out. Seems like more pressure would come from more volume, no? So, do you need pressure or volume to keep the engine properly lubed? I have a fully restricted motor, 8 qt pan and oil return lines. Sucking the pan dry is no a worry I have. I would just like to see a little higher oil pressure at idle.
Dwayne, whats your opinion on a stock out of the box melling hv oil pump vs one that has had all the tolerances blueprinted?

[Duane HTP]

Unless you have issues with a wornout engine, your oil pressure bypass valve in the oil pump is what controls your oil pressure. Your pump will pump well over 100 lbs of pressure easily. The bypass spring is what keeps it from doing just that. You can set the tension on the bypass spring to the pressure that you want. a cold engine with out a bypass would produce 200 lbs of oil pressure and blow up the oil filter if you didn't have the oil bypass. That's why they put them in the pump. They all have them somewhere. My blown 522 engine runs at 65 lbs on a hot day at WOT and idles at 40 lbs right after that. It has a .060" washer behind the bypass spring on a stock Melling pump.

[malcolm]

Taylorman, if a regular HV pump can't keep the pressure up, I doubt you'll see much improvment with a blueprinted one. My un-blueprinted HV melling never goes below 35 lbs. My high side pressure will drop some (50 psi) when the oil is shot, but comes right back to 60+ after a change. You can check your own pump out to see if it's the problem. Take the end plate off and stick a feeler gauge in there and see what kinda end clearance you've got. Then check between the gears. Then post your results and let everybody tell you how bad they are. :D Then you'll have your own blueprinted pump.

[waterslinger]

Men, I have a pal who is a pro race engine builder. Every pump gets a blueprint job. Most pumps have a very slopy set up stock.
Brent sets up his pumps tight .oo2 from gear to pump cover.
Out of the box most Melling pumps are from 005 to 007.
He has a oil pump dyno to set preasure before it is installed.
Has good prices on stroker kits (904) 298-2447.

[Havasu47]

"Blueprinting" the pump means checking and setting all the tolerances in an oil pump. By reducing the clearance between the gears and end plate to .002 to .003 you will increase the oil press. at idle with little increase at higher RPM's.
The Melling HV pump is a decent pump but regularly comes with too much end clearance.
We blueprint every pump on every engine we build.

[shaun]

whats it usually run to blueprint a oil pump? what kind of presures should the motor be running at idle and WOT?

[HammerDown]

Originally posted by waterslinger
Out of the box most Melling pumps are from 005 to 007.
Must have got lucky with mine...because "out of the box" my Mellings was "right on the money":cool: