The photo of the plungers shows 2 machined rings from georotor pumps, mine had none. Are they normal. Thanks

56 Vic, B'Ville 200 MPH Club Member, So Cal.

I’m just putting together my new y and was lucky enough to have to gerotator pumps. I found the number for the rebuild kit on a T’bird site from Gill Baumgartner. Melting kit came, went together and feels smooth as pie.

Mike, still lovin his 57 t'bird after 53 years!

I've acquired another with a standard piston style bypass.  It was listed as a Melling HV HP oil pump.  It didn't come in any box but it looks brand new.

The tag has HM42 and 91282.  The bottom plate looks cast with HP cast into it.  The main casting itself has 542 on one side and on another side, 5201 with a larger 2 to the right, with a diamond shaped logo which looks like it has the letters BCI in it.  I like the shape of the cover.  It provides a way to tell how to orient the cover.  On the stock ones, it's not so obvious.  Minor detail but nice if you take it apart.  The rotors are the same depth as stock so it's not a HV (High volume) pump.  None of the cover plate bolt holes are counterbored in this unit.  Come to think of it, that counter bored hole in the other may be for easier orientation of the cover to that unit.











The pump housing is most similar to an original ECG pump.  The cover plate end is clocked differently on a C1AE pump.
ECG left, Iron right.



The most apparent difference that may have any effect on performance (HP?) is the size and shape of the cavities in the housing,  the passage to the engine is more open and about .050" larger in diameter and the bypass passage into the rotor cavity is larger.  That bypass passage looks to be as cast in the iron unit and drilled in the originals.
I don't know if my other is similar in these areas.  I don't have pictures with the rotors removed and it is at Ted's at the moment.  That one wasn't advertised as anything special so I didn't think to take a closer look.

Iron:



C1AE:



ECG:



The bypass piston is different from the stock gerotor pumps I've taken apart but looks to be the same as at least one piston I have removed from a spur gear pump.

Center and left, original gerotor.  Right Iron:



Differences on the block side.
C1AE left, Iron Right:



ECG left, Iron right:





Lawrenceville, GA

Try this link for some more detail.
https://www.aa1car.com/library/oil_pumps_high_flow.htm 

Lorena, Texas (South of Waco)

Where can I find info about "paddle wheel" tech?


Lawrenceville, GA

Dang. Thought I had something there..

Dave

No, gerotor and spur gear parts are not interchangeable at all.

John - "The Hoosier Hurricane"

Along the lines of this subject I have a question. Ted has an article where he fabricated a hi volume oil pump for a Y. My question is since finding a Gerotor pump is damn near impossible can you use a Melling Gerotor rebuild kit and use it in the spur gear housing?

Dave

I did find out some of the back story for the iron gerotor oil pumps that use the check ball for the bypass rather than a piston.  Those pumps were made specifically for the military as there was an issue with the oil relief valve pistons ‘sticking’ when the engines set up for extended periods of time.  The use of a ball fixed that particular problem.
 
Charlie.  I am getting closer to performing a full blown oil pump test on the dyno mule which will include your ‘ball relief valve’ oil pump.  Driving this upcoming dyno test is the development of a new oil pump for the Y.
 
There is a new oil pump for the Y being designed as we speak that will incorporate what is called ‘paddle wheel’ technology.  That new pump is also incorporating a spring loaded ball instead of a spring loaded piston for the relief valve.  The 'paddle wheel' technology is already being used on some specialty oil pumps for other applications and that new technology has solved some of the issues with the normally slow exit speed of the oil when using spur gear oil pumps.

Lorena, Texas (South of Waco)

I haven't made any modifications, yet.


Lawrenceville, GA