48 Pan Check Valve Seating Problem

[T. Cotten]

One more time, Folks,...

Using bubbles at ~4psi, you can actually see the degree of leakage at the ball check, before you reassemble.

A piloted flat stone can remove just the damaged seat, leaving an edge.
(Many of you know from poppet valves that a thin seat seals best.)

Any attempts to burnish, lap, smack with a drift, or otherwise dress this edge only increased leakage.

We are all anxious for a provable solution.

....Cotten

[rthrift]

Well damn, Cotten! No progress? I bought one of your burnishers a decade ago, it didn't help, and here I was trying to look up what else you might recommend.

[T. Cotten]

Did you bench test it, Greg?

CHEKTEST.jpg

....Cotten

[harleygreg]

Hi Guys – my problem seems to have solved itself for the time being, in that I am only getting a few cc’s a week leakage now, with the bike idle for the week. Measuring the oil is a simple, somewhat inaccurate, test, but at the end of the day, I’m just trying to minimise leakage to the crankcase.

However, I have devised a solution requiring minimal cost and tooling, inspired by both your comments.

oil pump 1.JPG

Here we have a 3/8” ball bearing, drilled and tapped (off the web for $2, including the drilled and tapped hole) with the ball lightly scuffed with emery paper, for use with lapping compound.

Attached to it, is a screw/allen bolt, and for directional stability, if needed, you could drill a hole in an old ‘check valve spring cover screw’, as I note you have both done with your tools. This setup would allow the fix to be done ‘in situ’, and you could always use a flexible drill shaft and a slow battery screwdriver for greater purchase and efficiency.

[T. Cotten]

Thanks for all these comments, I'm going to try the lapping in first and see what we get. I may be some time.

How ya gonna know it worked, HarleyGreg?

Put it back together and wait?

....Cotten

[harleygreg]

Thanks for all these comments, I'm going to try the lapping in first and see what we get. I may be some time.

[Jerry Wieland]

I think I might still have a couple of them. I'll look. Jerry

I've only encountered two sdevalves, Jerry!

That were extremely hard and brittle.

The rest were malleable iron or steel.

It would be nice if someone had a genuine NOS pump and could tell us what the seat looked like.

.....Cotten

[T. Cotten]

Did they cut it before they 'chilled' it?

Jerry

I've only encountered two sdevalves, Jerry!

That were extremely hard and brittle.

The rest were malleable iron or steel.

It would be nice if someone had a genuine NOS pump and could tell us what the seat looked like.

.....Cotten

[Jerry Wieland]

Thank you for summing up our failures, Bob!

Once again, any technique that produces fewer bubbles than a flat grind will make a lot of people happier than my efforts.

Aside from concentricity issues for the burnisher, some Flatty pumps turned out to be "chilled", so hard that they destroyed the burnisher, and further eroded the seat. So in order to 'do no harm', I gave up.
This is in spite of many astounding successes (and a painful investment).

Again I ask, Folks:

How did the MOCO do it?

...Cotten

Did they cut it before they 'chilled' it?

Jerry

[T. Cotten]

Thank you for summing up our failures, Bob!

Once again, any technique that produces fewer bubbles than a flat grind will make a lot of people happier than my efforts.

Aside from concentricity issues for the burnisher, some Flatty pumps turned out to be "chilled", so hard that they destroyed the burnisher, and further eroded the seat. So in order to 'do no harm', I gave up.
This is in spite of many astounding successes (and a painful investment).

Again I ask, Folks:

How did the MOCO do it?

...Cotten

[BigLakeBob]

Harleygreg, your first post you asked is there a different approach. Since this is your thread and question I tried to answer that in post # 14 as what has worked for me. I will attach a picture of the orig tool I used, then my updated tool I made, along with a tool I bought from Tom to burnish the seat which after about a month later he put out a disclaimer not to use his tool because of oil pump concentricty issues, and that does make sense. I realize you may not have a machine shop at you disposal, but I feel any tool with a 3/16 radius (3/8 dia. ball such as an old pushrod will work). My advise is to make some grooves in the ball to hold the compound,use fine lapping compound, and work it back in forth in a circular motion, raising it and rotating it to distribute the compound. It does not take much, go lightly with the compound. I think, with my experience, a slight angle or even a slight radius formed by this method will seal the area. I disagree with a flat bottom then also making the thru hole round. Best of luck Greg.

Tom, in post #13 you invite a different or better approach even though this is not your thread, kinda funny. I am trying to do that. Now you say, make the thru hole round! So Harleygreg has to not only make the bottom edge flat but now he has to make the thru hole round. No disrespect, you are always offering your many years of experience with pictures of proof, but I feel this is a much too complicated approach. You will probably disagree, but I am answering Harleygreg's question with my own successful experience.

P.S. Mike Love, attaching pictures is so much easier and user friendly, Thank You and to whoever made it possible.

DSC06645.JPGDSC06646.JPG

[T. Cotten]

The edge method will only work, in my opinion, if the thru hole is exactly round. I believe a small (in length) angle that is round regardless of the thru hole roundness would be better.

So make round if it ain't. Bob!

A little Prussian Blue will tell.

....Cotten

[BigLakeBob]

That's exactly why, Bob,...

My best bubble-test results were with a 'zero' angle. Or maybe its ninety, but I mean flat-ground, and to an edge.

The edge method will only work, in my opinion, if the thru hole is exactly round. I believe a small (in length) angle that is round regardless of the thru hole roundness would be better.

[T. Cotten]

I was just thinking, just because there is a new angle put on, maybe the angle is not round, this would make the ball not seal. Hard to do by hand. Could get 'wollard'. Again, I've had real good luck lapping by hand with a fine compound, 400 to 600. My 2 cents, good luck.

That's exactly why, Bob,...

My best bubble-test results were with a 'zero' angle. Or maybe its ninety, but I mean flat-ground, and to an edge.

But attempts to lapp (with either a ball siver-soldered to a rod, or the piloted tool shown in the middle of my last pic, or even the end of a pushrod), or any other abuse, only produced much more bubbling.

So our primary focus should be: How did the MOCO do it?

....Cotten

[BigLakeBob]

I was just thinking, just because there is a new angle put on, maybe the angle is not round, this would make the ball not seal. Hard to do by hand. Could get 'wollard'. Again, I've had real good luck lapping by hand with a fine compound, 400 to 600. My 2 cents, good luck.