Melling pump cover bolt torque

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I wouldn't coat the innards of an oil pump if you held a gun to my head. JMHO.
 
hydrodynamic wedge, pretty F'n slippery! Melling says 80-106 in lbs no lube on a similar chevy pump cover.
 
yellow rose said:
Depends on the coating. The older stuff...not again. This newer stuff...id damn sure give it a try.
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This is the attitude, I agree with the powder coating. But not a coating, find something that has a spec rating like the rating I listed. Then tell me what it is, I don't think you will find one, not one you can do in your garage.
 
Well just for giggles tore it all apart, had some plastic gauge and meassured gear to cover and gear to housing, for both got .0015, so total is . 003 clearance, is that around spec anyone know?
 
RustyRatRod said:
I wouldn't coat the innards of an oil pump if you held a gun to my head. JMHO.
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I was waiting for this:

I wouldn't coat the innards of an oil pump if you promised me sex with (enter name of hottest woman you know of)
 
yellow rose said:
Does your paper work say exactly which coating they used? The have some that are only .0002-.0003 thick and that's what I'd ASSume they used but I could be wrong.

They have coatings that can close up piston clearance by up to .020 so that's something I may use on a vintage dirt bike I need to make run.
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WHY WOULD U FEEL THE NEED FOR COATING THE INSIDES? The pumps are only supposed to have .00125 to .004 to start with !!
 
Matts440 said:
Well just for giggles tore it all apart, had some plastic gauge and meassured gear to cover and gear to housing, for both got .0015, so total is . 003 clearance, is that around spec anyone know?
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It should spin free and easy with that much end clearance. So what do you think is jamming it up? Gotta be something in there....maybe some high spots in the coatings?

I guess see your intent with the coating to keep up the idle pressures... by decreasing the clearances. But most of the pressure leakage comes from around the tooth-to-tooth and tooth-to-housing clearances... dunno if your gears are coated there. Be aware that the HV model pump will increase pressures at idle and lower RPM's, simply due to the 20% taller gearset.
 
nm9stheham said:
It should spin free and easy with that much end clearance. So what do you think is jamming it up? Gotta be something in there....maybe some high spots in the coatings?

I guess see your intent with the coating to keep up the idle pressures... by decreasing the clearances. But most of the pressure leakage comes from around the tooth-to-tooth and tooth-to-housing clearances... dunno if your gears are coated there. Be aware that the HV model pump will increase pressures at idle and lower RPM's, simply due to the 20% taller gearset.
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Since nobody has asked--I'll ask. What is coating the inside of an oil pump supposed to accomplish? Also--pics? J.Rob
 
Going to dive more into it today, but the outer and inner gear were both coated along with the wall that the outer gear slides on, and the area on the cover that is over the both gears. Straight edged the gear in the cover last night very minimal light will feeler gauge it today.
 
RAMM said:
Since nobody has asked--I'll ask. What is coating the inside of an oil pump supposed to accomplish? Also--pics? J.Rob
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It is to boost psi a bit at idle and through out the rpm range a bit, also help with wear, and heat on the gears. I'll get some pictures up today too
 
Help with wear and heat on the gears. Now that's a good one. You boys just keep believin that good old marketing crappola.

Where does an oil pump spend its life? IN OIL. What does it spend its life doin? PUMPIN OIL. Trust me, it's WELL lubricated and WELL cooled. That is to say until some "MOE-RAHN" lets the pan run dry.
 
RustyRatRod said:
Help with wear and heat on the gears. Now that's a good one. You boys just keep believin that good old marketing crappola.

Where does an oil pump spend its life? IN OIL. What does it spend its life doin? PUMPIN OIL. Trust me, it's WELL lubricated and WELL cooled. That is to say until some "MOE-RAHN" lets the pan run dry.
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^This is exactly what I'm thinking. WTF! Take apart almost any oil pump and unless a lot of dirty oil went through it-guess what? It looks like new inside. Consider almost all oil pump housings are made from aluminum now and that may seem like a bad idea at first, but they don't wear at all. Why? Cuz the **** never touches. Reduced oil temp-ha! Maybe a tenth of a degree-maybe. J.Rob
 
I had it done to help with efficiency and help boost psi at lower speeds, it is mast produced and not perfect, and if this design is so perfect then why do is there a need to offer these coating, even melling on there billet pumps have a costing done to the gears. Everyone can believe what they want, lots of teams use coating on alot of things, even rear gears and seen lower temps and they are always in gear oil. Guess you don't buy pistons with this protection either since its a bunch of non sense, keeps tolerances longer. To each is there own nice thing about this hobby. If you buy your pumps from precision oil pump those are all coated gears too.
 
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Side note: has anyone threaded the spring area to get rid of the freeze type plug, could make for a adjustable pressure over shimming. Thoughts??
 
Matts440 said:
Side note: has anyone threaded the spring area to get rid of the freeze type plug, could make for a adjustable pressure over shimming. Thoughts??
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Only problem with that is the pump is in the pan! Pull the pan to adjust?
 
Here are the pictures of the coated gears and housing

20180602_134151.jpg


20180602_134158.jpg


20180602_134206.jpg
 
Got it fixed, it was the outer gear was binding, uses a red 3m scuffing pad to clean those off enough to clear, plus used a razor blade to clean the high spots off the tips of the inner gear. Benched tested of sorts feed it oil and sound it with a drill and driver, kept feed it oil till the black stuff turned clear, probably the coating breaking in. Now just need to get another 5/8" plug to fully reassemble.
 
So I guess my question is what happens to the stuff that wears off while it is breaking in, and how long does it take to break in. I hope everything gets stuck in the filter?
 
Well that's why I ran the pump on the bench till its clear before I install it on the engine, I did high and low speeds with the drill, took it all apart again, cleaned everything off again, carb cleaned the housing, dried it, reassemble with engine oil again, torqued the cap down.
 
brian6pac said:
So I guess my question is what happens to the stuff that wears off while it is breaking in, and how long does it take to break in. I hope everything gets stuck in the filter?
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Like is said...it depends on the coating they used. If it's abradable like they use on the Pistons it is self clearancing and the particles do no damage to the engine.

This coating has been out long enough to be better known.
 
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