Melling Shark Tooth Oil Pump

Loves302Chevy

"One test is worth a thousand expert opinions."
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Hey Grumpy, have you seen this yet?
http://www.competitionproducts.com/Melling-Shark-Tooth-Oil-Pumps/products/2735/
This design is significantly smoother through the use of new helical asymmetrical gears. The new gear design provides the engine with an improved flow of oil without the usual pulsing found in traditional gear pumps. Significant reduction in pressure ripple (pulsing). Reduction in torque ripple in the pump drive. Improved distributor operation - reduction in spark scatter. Improved distributor gear and intermediate shaft wear. Includes chrome moly intermediate shaft with steel guide.
 
Interesting Mike.
Its a Recap idea that Pontiac Motors used all thier V8 engines 1955-1959.
Pontiac 287, 316, 347, 370, & 1st year 389...all had Helical cut oil pump gears stock.
Never knew till recent.
Peformance years / Max Pontiac Main Mod tore down his 1959 389 V8 & took pictures for us Pontiac Guys.
 
Interesting Mike.
Its a Recap idea that Pontiac Motors used all thier V8 engines 1955-1959.
Pontiac 287, 316, 347, 370, & 1st year 389...all had Helical cut oil pump gears stock.
Never knew till recent.
Peformance years / Max Pontiac Main Mod tore down his 1959 389 V8 & took pictures for us Pontiac Guys.
Those OLD engine designers had it right!
This is one of those, DUH - Why didn't I think of that, ideas.
 
Early Pontiac engines were reverse cooled too, sometimes things that look/appear better are not.

Thanks
Randt
 
while helical cut gears will run smoother ,
( ESPECIALLY WITH THE STOCK 7 tooth SBC oil pump)
as you potentially have 2 or three gear teeth in various stages of gear tooth contact
(depends on the angle of tooth engaugement)
and yes the design will reduce a tendency to produce a pressure pulse, I have not seen this as a major issue.
simply swapping to the standard volume and pressure BIG BLOCK 12 tooth oil pump in a SBC engine all but eliminates the pulse and pressure and volume issues a sbc oil pump has.

keep in mind fluids like oil, are not compressible the resistance to flow increases as the pump is turned simply because the oil flow exiting the oil pump is flowing through the bearing clearances thus the oil flow exiting the oil pump is being restricted, if the engine was rotating the restriction too oil flow is reduced.
if the oil pumps pressure relief valve opens as designed max resistance is limited to the pump producing flow rates that will build until resistance to that flow volume reaches about 60 psi, when the pressure relief valve opens re-ce-recirculating additional oil flow back to the low pressure side of the oil pump.remember volume increases as rpms increase up to the point where the relief valve opens limiting pump flow.

http://garage.grumpysperformance.com/index.php?thr...

http://garage.grumpysperformance.com/index.php?thr...

http://garage.grumpysperformance.com/index.php?thr...

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http://www.hotrod.com/articles/ccrp-0911-small-block-chevy-oil-pumps/

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failure to use the correct oil pump,mounting stud, bolt or nut or
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carefully check clearances when mounting an oil pump can cause problems
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ONE RATHER COMMON MISTAKE IS USING THE WRONG OIL PUMP STUD OR BOLT TO MOUNT ,
THE OIL PUMP AS IF EITHER EXTENDS THRU THE REAR MAIN CAP,
IT CAN AND WILL BIND ON THE BEARING ,
AND LOCK OR RESTRICT, SMOOTH ROTATION

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when you inspect the bye-pass piston and spring or replace the oil pumps bye-pass spring, in the oil pump you must be certain it smoothly slides through the internal passage , if it binds it will cause issues with erratic oil pressure
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simply swapping to the standard volume and pressure BIG BLOCK 12 tooth oil pump in a SBC engine all but eliminates the pulse and pressure and volume issues a sbc oil pump has.
I agree. And I would do that before I spent $150. for that ST oil pump.
 
hello gang...

So here I am with my fully rebuilt '69 LM1 which by the way is running fantastic. Smooth as silk, engine is steady as a rock at idle, and you can feel the power even though I haven't jumped on it (because I'm still breaking it in). I got to this point because of a lot of solid advise from folks on here...thank you. Especially Grumpyvette who gave a lot of good and well thought out advice.

So after all that, there's one thing bugging me. The oil pump seems to be "noisy". Now Grumpy if you're reading this know I've already been to your forum and read the links on pump noise and that it shouldn't really have any, causes etc. So let me first qualify "noise".

As the engine runs, you can here a whirling almost like a belt driven accessory or gear whine but its quiet enough that you'd never notice if you weren't looking for things (new engine, after all). Using a stethoscope I confirmed it is loudest at the sump end of the pan. The stethoscope defined it better to be a little more of a sound you would expect from two gears meshing. Once the engine is at operating temp it becomes undetectable to the ear.

The pump is a new Melling M155 with helical cut gears, (shark tooth) with the stock (58#) relief spring. I used Mellings steel-coupling drive shaft and confirmed it to be the correct one for the block. I opened the pump and measured everything inside for clearence and all was good, and I put assy lube on the gears and then primed the pump with oil before install. There is lots of distributor to drive shaft clearance, with the disty fully installed I can pull the rotor up almost 3/16", if anything it may be too much clearance. Finally the pan was clearanced to the pump, the pickup was set 1/2" pff the bottom of the pan including accounting for the felpro 1-pc gasket. When I drill-primed the engine, I thought the pump was on the loud side but other than volume, no unusual sounds, and it spun without any kind of binding. Oil pressure is great and consistent. I'm running Brad Penn Grade 1 10W30

I feel like I've done everything right, but it feels wrong that I should be able to hear it at all with the engine running. Before the rebuild I never heard the oil pump. But then again that pump was 48 years old with 130K miles on it and God knows how clean the oil may or may not have been before I got it, or how much wear it may have had. But the M155 is a higher flow pump (but not HV - those things are taller and need a different pan, and would be too much for my stock rebuild with stock bearing clearances) so maybe being new + higher flow, it makes more noise.

Finally, I called Melling and they said "oh yeah, don't worry about it". But its the oil pump, and a new engine. Of course I'm going to worry. Its what I do best in the absence of sound facts.
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So tell me, am I being paranoid?



got too ask , why the fascination with the hectically cut oil pump gears?
yeah I'm well aware of what melling says,
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SHARK-08.jpg

Melling Shark Tool Oil Pump
This design is significantly smoother through the use of new helical asymmetrical gears. The new gear design provides the engine with an improved flow of oil without the usual pulsing found in traditional gear pumps. Significant reduction in pressure ripple (pulsing). Reduction in torque ripple in the pump drive. Improved distributor operation - reduction in spark scatter. Improved distributor gear and intermediate shaft wear. Includes chrome moly intermediate shaft with steel guide
simply swapping to the standard volume and pressure BIG BLOCK 12 tooth oil pump in a SBC engine all but eliminates the pulse and pressure and volume issues a sbc oil pump has.
http://www.competitionproducts.com/...ard-Volume/productinfo/MOR22150/#.Wyucl6dKi9I
Ive had zero issues using a standard volum big block pump in performance builds on sbc engines
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sbcvsbbcgearsa.jpg


keep in mind fluids like oil, are not compressible the resistance to flow increases as the pump is turned simply because the oil flow exiting the oil pump is flowing through the bearing clearances thus the oil flow exiting the oil pump is being restricted, if the engine was rotating the restriction too oil flow is reduced. but keep in mind oil pumps spin at half the crank rpm, and as rpms increase so does the out put oil flow until the by-pass valve opens if the pressure builds up to the point it pushes open the by-pass valve.
if the oil pumps pressure relief valve opens as designed max resistance is limited to the pump producing flow rates that will build until resistance to that flow volume reaches about 60 psi, when the pressure relief valve opens re-ce-recirculating additional oil flow back to the low pressure side of the oil pump.remember volume increases as rpms increase up to the point where the relief valve opens limiting pump flow.
http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/page-2#post-75256
http://garage.grumpysperformance.com/index.php?threads/bearings-and-oil-flow.150/#post-68205
http://garage.grumpysperformance.co...l-pumps-pressure-bye-pass-circuit-works.3536/


heres a video that shows the noise he is referring too,

 
GRUMPY...I used a mic to measure the gears in the new pump, basically they had 0.0005" clearance to the bottom casting face. I used a piece of glass as a flat surface and sanded both gears until I acheived 0.002". I also use a file to break the top and bottom edges of the gears as they were very sharp. Installed the 58# pressure spring after tig welding the pickup on (yes I removed the check valve first before putting the heat on it!). Pressed the drive shaft on (what a nice fit by the way, it would take significant effort to pull this one off but the groove on the pump shaft is wider than the ridge in the driveshaft so there is still some axial play and the instructions with the shaft say that this is the desired outcome. Primed it and threw it in the motor.
Now to bolting it on, one thing I noticed with the original oil pump, the M155 I replaced it with and now this one. When you put the pump onto the mount face on the rear main cap, the pump will rock slightly indicating that mounting face is higher in the middle than at the dowels. I'm talking probably 0.001" or less. I don't really like that, but both the original pump and the M155 have witness marks showing full contact to the face all around when torqued. So I put this one on and torqued to 65ft-lbs.
One note, Grumpy's site talks about being careful not to have the bolt put pressue on the back side of the bearing. My main cap is blind-drilled (not through hole) and the bolt length is less than the depth of the pump+threaded hole depth so even with bolt stretch it won't bottom out. At least that's one thing I can rule out here when trying to understand what the noise was.
BTW - I followed the GM instruction on pulling the pan without pulling the motor. They missed a couple of important notes, such as 1) if your car has A/C, you need to remove the compressor and lay it aside because the A/C hoses don't have enough movement to allow the lift. 2) They recomment unbolting the rad and letting it hang there so it will lift with the motor. Bad idea, it will put strain on the hoses, transmission lines, hose clamps etc. It will also cause the fan blades to bear a lot of the weight of the full rad as the fan shroud bears on the blades. I got my engine hoist and used some wire to "hang" the rad on the hoist boom and lifted it with the motor so all the connections remained on the same plane. 3) The book says to use 4" blocks of wood under the engine mounts. I used 2x4's. A 2x4 is actually 3.5". Turns out that's enough to make it not work. The book says 4" and it has to be 4" and with that, you'll have about 1/4" clearance to get the pan down but only after you disconnect the idler arm from the chassis and let that whole linkage hang.
Well, it's all back together and when drill-priming I immediately noticed a difference, so much quieter. After that, running it at various speeds and loads, both with warmed up oil and cold, failed to produce the noise originally complained about in any way shape or form.
I'll pronounce the issue resolved with the root cause being either the pump drive or the pump itself. Curiousity will cause me to evaluate those components deeper "on the bench" for future reference. Thanks everyone who commented for the tips!
 
I was told in the past not to use a Big Block Chevy Oil pump on a 010 Factory Block with factory main caps.
The Big Block oil pump is heavier.
Rough dirt tracks caused the #5 maincap oil pump boss to break off.
Race ended for them.
Back in my dirt track engine buiding days.
We used Melling High Volume pumps SBC.
Later Melling select.
 
In that video, that preluber shaft has no stop collar, meaning that when running the drill motor, you are pushing down on it
which directly transfers that force to the drive gear inside the pump, forcing it into the cover. Good way to ruin a new oil pump.
That could have contributed to the noise that the OP was hearing.
 
Hmm... Carl Hinkson from CNC blocks recently reported VERY high oil pressures from a couple Melling SharkTooth oil pumps on a 383.

Here's a picture of the engine on the dyno with 70 PSI oil pressure @ 4,000 RPM and 98 PSI @ 5,900 RPM. https://www.facebook.com/photo/?fbid=10220537968989829&set=pcb.10220537988870326

He says that the bypass valve is too long and not exposing enough of the bypass hole.
Apparently lots of people have been reporting super high oil pressure with these for a while and some builders have just stopped using them for that reason.

Here's a picture looking into the bypass hole of a 10555 Shark Tooth showing just how much of the hole is blocked.

A few folks have found shortening the pressure relief valve a specific measured quantity for each pump solves the problem.

Carl has reported it to Brian from Melling and everyone's waiting for an "official" reply, but it seems like some major QC issues and there's no fix that can be done without voiding the warrantee...

My engine is sitting on my engine stand and I had a helper to help me install it NEXT weekend, but I'm now in oil pump limbo as I have a 10552ST sitting on mine and removing my oil pan on my C3 with the rack and pinion conversion is NOT remotely easy... This has to get resolved before I reinstall the engine...

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Not cool...

I've never taken an oil pump apart, so I don't totally understand what the problem is. Can someone dumb it down for an oil pump pressure relief newbie?


Adam
 
Carl's contacted Brian @ Mellings and they're looking into it as of 2 days ago, but it seems like the problem goes back at least 2 1/2 years... So far Melling has confirmed that the case design was altered slightly at some point in time...

How you can have customers reporting high oil pressure and engine builders giving up on your "premium" pumps for 2 1/2 years and you don't troubleshoot it to root cause for 2 years is beyond me.
 
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Guess you didn't see this post a few days ago.

.
 
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Sure didn't... Thanks!

I'm going to wait another 5 days or so to see if Melling comes back with an official reply and unless they state they'll take these back and swap for a verified fixed pump, I might just have my local machine shop measure and machine the bypass valve, if necessary...


Adam

[Edit] I just reached out to Action Machine in Shoreline, Washington to see how long it would take them to get to this, if I dropped it off tomorrow. They've been just fantastic for all the small stuff I've used them for so far. (20x better than the other area machine shop-of-chaos that I used before them....)
 
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