Board index Flathead Power-Technical Questions, Answers, and Suggestions Big Twin Flatties Oil pumps

Oil pumps

Post Mon Sep 03, 2007 4:36 pm

Posts: 543
Location: Wa, USA
Does anyone have an NOS return pump gasket? If so, could you measure the thickness and let me know what it is? The repops I have are .020" and I seem to remember the originals I used years ago as being much thinner.

Post Mon Sep 10, 2007 12:00 pm

Posts: 152
Location: Carver, MN

Don't have any OEM to measure, but I can tell you that one from "James Gaskets" measures .010" and the same gasket from "45 Parts Depot" measures .006" I have also seen "off brands" at about .020" This would lead me to beleive the OEM gasket was probabley about .006" thick

Post Mon Sep 10, 2007 9:49 pm
don User avatar

Posts: 575
Location: Spokane WA USA
I got .010 on both out of a 50-36 gasket set.
They are a little dry, I did compress.
Stan Dishong told me once, Soak them in water when they shrivel up.
I also have used Chart Paper.
don

Post Tue Sep 11, 2007 6:42 pm

Posts: 543
Location: Wa, USA
Thanks, Don and Lee. I was getting the same variation in measuring various gaskets. I made one out of a paper grocery bag (.006"). I am getting ready to run a test on a pump to find out how much oil (gallons per minute) these pumps are capable of pumping and I want to make sure that it is not too loose.

Post Tue Sep 11, 2007 8:23 pm

Posts: 152
Location: Carver, MN

Great idea. Hope you will post your results. It would be really interesting to see what the difference would be with the thicker gaskets!

Post Wed Sep 12, 2007 5:36 am

Posts: 1676
Location: Interlaken, NY USA

just as a point of reference, a '72 up sportster supply pump puts out 1 liter/minute @ 1000 pump rpm. I think that's about 3 times what the stock pump does. I did some testing last winter. Let us know what you find out, I never did any testing on return pumping.
Here's a link to my test setup. http://www.freewebs.com/dicky_linn/modi ... typump.htm
Dr Dick

Post Wed Sep 12, 2007 6:21 am

Posts: 67
A dollar bill makes a pretty good gasket.

Post Thu Sep 13, 2007 8:10 am

Posts: 1676
Location: Interlaken, NY USA

Hey, I like that idea, I've been making gaskets from cardboard, paper, etc for years, and eventually, most materials disintegrate. That paper money is tough stuff, bet it does work good.
Dr Dick

Post Thu Sep 13, 2007 7:22 pm

Posts: 543
Location: Wa, USA
Thanks for the info on the sporty pump flow, Dr. Dick. This is only the first part of a long term project. I am looking at the possiblity of using a sportster breather gear, making a center section ala sporty with the flatty return pump configuration that uses the flatty return gears on top for return and the sporty feed gears on the bottom. The first part is finding out if the flatty return pump can handle what the sporty pump can put out. I have a sporty breather gear, but am still looking for a complete sporty pump to get the gears from. I have been watching Ebay, but have not found anything that does not go too high, yet. I will post my findings on this project as it progresses.

Post Fri Sep 14, 2007 6:16 am

Posts: 1676
Location: Interlaken, NY USA

Woody, yeah, the sporty pumps are going kinda high on ebay these days. I'm in the market for a second one for my BT chopper I'm building this winter. Maybe we'd better email so we don't compete!!
Dr Dick

Post Sat Sep 15, 2007 9:18 pm
JIm

Posts: 801
Location: Planet Earth
Here is something I am working on that has some test results on stock as well as modified oil pumps.
http://www.flatheadworks.com
It should be done by the end of the month.

Jim

Post Sat Sep 15, 2007 9:54 pm

Posts: 976
Location: Markt Einersheim, Germany

Jim..

I'm in... let me know when it is in print.

Ya still got my e-mail and address don't ya?

George

Post Sun Sep 16, 2007 4:30 am
Pa Site Admin

Posts: 5841
Location: Ohio USA

Ditto !!!!!!!!!! Pa

Post Mon Sep 17, 2007 9:21 pm
JIm

Posts: 801
Location: Planet Earth
George'

Should still have it.

Going through a lot of crap in work that has been holding me back from getting it done. Thought we were out of the woods but it doesn't look good right now.
I am hopefully on the final rewrite.

Jim

Post Tue Sep 18, 2007 8:01 pm

Posts: 976
Location: Markt Einersheim, Germany

JIm,

I can wait........

Just let me know when..

George

Post Thu Sep 20, 2007 8:19 am
panic

Although I haven't tried the mods suggested by Jim, he has graciously supplied me with some results and details and I'm very impressed. The research appears very thorough, and this is a mod worth applying to any high-performance flathead motor.

Post Fri Sep 21, 2007 9:16 pm
JIm

Posts: 801
Location: Planet Earth
Thanks the Panic.

Close to completion, format changes are done, the final rewrite is close to done. Still shooting for the end of September or very early October.

Jim

Post Sat Oct 27, 2007 4:39 pm

Posts: 543
Location: Wa, USA
Jim, have you done any unrestricted flow tests on the unmodified flatside pump? I just finished testing a return pump with gravity feed and unrestricted output. The pump flows at .55 gal. per minute at 2400 engine RPM.

Post Sat Oct 27, 2007 9:08 pm
JIm

Posts: 801
Location: Planet Earth
Woody,
All the test I did on the oil pump were with the pump installed as if it were on a running motor. I will be running more test on the feed pump this winter. The oil pump, sock or modified, does not put out anywhere near the volume you list for the return pump. All the test I did were repeated 4 times with the same results every time. Your numbers tell me that the return pump can handle more than I thought.
Jim

Post Sun Oct 28, 2007 8:29 am

Posts: 1676
Location: Interlaken, NY USA

Woody, thanks for doing the research, I have been very curious about the return pump capacity. Sounds like the return pump could handle a lot more feed than the present pump supplies. I'm wondering if any one on the board knows enough hydraulics theory to determine if output volume scales in a linear fashion with pump speed. I wonder as I did my tests at 1000 pump rpm, (all my jig would handle), and you did your work at 2400rpm. If they do scale, sounds like the flatty return pump is roughly equivalent to the 72up sporty supply pump. For the perverse out there, imagine a flatty return pump grafted on where the present supply pump is, and a revised return pump with a spacer plate and bigger gears in the return position.
Thanks for the info,
Dr Dick

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