Melling Shark Tooth Oil Pump

Discussion in 'Oil and Lube Systems' started by Loves302Chevy, May 21, 2016.

  1. Loves302Chevy

    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.
     
  2. 87vette81big

    87vette81big Guest

    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.
     
  3. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    Those OLD engine designers had it right!
    This is one of those, DUH - Why didn't I think of that, ideas.
     
  4. GLHS60

    GLHS60 Well-Known Member

    Early Pontiac engines were reverse cooled too, sometimes things that look/appear better are not.

    Thanks
    Randt
     
  5. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    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.


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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 [​IMG]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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    Last edited: Jun 21, 2018
  6. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    I agree. And I would do that before I spent $150. for that ST oil pump.
     
  7. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member



    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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    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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    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,

     
  8. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

     
  9. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    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.
     
  10. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    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.
     

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