1929 mechanical oiler question

[Steve Swan]

My buddy is getting his first few miles on his '29 and now preparing for predesignated rides to adjust his mechanical oiler output. Oil is getting past the oiler into the crankcase at the rate of more than one ounce in seven days. Would appreciate hearing what may be the causes of the oiler allowing oil to get past it and into the crankcase.

my buddy would like to know if anyone rebuilds the mechanical oiler?

His hand pump check valve does not allow any oil into the crankcase.

Thanks in advance!

[Steve Slocombe]

Dear Steve, those steel oil pumps are usually pretty good. At one ounce per week I would first look for a slow leak round the hand oil pump check valve. Disconnecting the hand oil line will show it over a couple of days. If not, then it must be the plunger wearing a few thou loose in the pump body, for which there is no easy fix. The pumps are simple and the average person should be able to strip and understand them. The similar 1930-33 VL oil pump is described in my VL book, with an exploded diagram made by laying out the parts on a white sheet.

[Steve Swan]

Thanks Steve for your reply. His hand pump check valve let no oil by after sitting. with the pipe off. As you say, it must be the the mechanical oiler's plunger is worn. We are wondering if some of these newer coatings might add however many thousanths is missing.

[aumick10]

Steve,
One way to build up the pistons is to hard chrome them, then grind them back to whatever size is needed. This is not decorative chrome, it is an industrial strength coating.
Being so small may be an issue with handling.
Mick

[exeric]

A bit over an ounce in 7 days doesn't sound that bad. I would consider that part of the price one pays for enjoying a running JD. I would consider having the tools, and a cup handy (in the toolbox) for easily draining the crankcase and pouring it back in the tank. Perhaps even a petcock. Most bikers stop frequently for all sorts of reasons. Now your buddy has a good reason for stopping

[Steve Slocombe]

I tend to agree with Eric, and have not had to try the hard chrome method yet. The 1934-36 VL oil pumps are more prone to leaking, as the diecast body was not a great choice to take a hardened steel piston.

[aumick10]

Upon reflection, hard chrome is probably not a viable option anyway, parts are to small, probably easier to make new pistons.
Where does the wear typically occur, the two small pistons, or the rotating part to the pump body.
If the pump bodies are wearing, is it viable to sleeve it, like an Amal carby sleeve?
Cheers,
Mick.

[exeric]

I'm just going to throw this out there; if a person wanted to tighten the tolerance of the pistons, would a soft plating like zinc, or cadmium be less likely to chip, or flake? It may not last that many years, but how many miles does one plan to ride a 1929 JD?

[Steve Swan]

Gentlemen, thank you for your replies and comments. i have heard of some coatings used in aerospace, but it was some time ago and can't remember what they were/are.......

[ryan]

There is an add in our last magazine that listed a build up coating for cylinder walls. You may want to give them a call, you cannot miss the add. What is the piston diameter and what seals it to the wall?

[aumick10]

Eric, that is an interesting idea, but i don't think I would like to experiment with a good motor.
Your original comment of that is the price we pay is probably the easiest way to live with it. Put a tap in the oil line?

If it becomes necessary to repair the pump, I think the best way would be to hone out the piston bores in the rotating body to ensure it is round. Then have a hardened steel rod centerless ground to whatever the OD needs to be. Cut the rod to length and radius the ends on a belt sander.
The body and pistons were probably made from a hard grade of metal, which i don't think would wear much, as long as it was kept in oil.

I would think the most wear would occur in the cast iron pump body where the piston body rotates.
This is an area where the hone round and build up the piston body with hard chrome would work. You would only need to chrome the surfaces that meet the cast body, then grind to size.
Either of these solutions is a fiddly job, and probably not worth the effort unless you absolutely had to restore a pump. In another 50 years, it may become a standard process if nobody ends up manufacturing new pumps.
Cheers,
Mick

[Steve Slocombe]

I go along with the wait 50 years plan. It could still be the hand oil pump check valve, which is worth stripping and checking. And swap meet mechanical pumps are still around for less than the cost of the remedial work we've been discussing.

[Steve Swan]

Gentlemen, thank you for this lively discussion on the mechanical oiler. my buddy is going to have an adjustment period accepting over all his '29's overall oily nature but i am confident he'll do it with a broad smile on his face!

[aumick10]

I am trying to figure out how these mechanical oilers work.
Going with the direction label, and the cable pulls the pump open, the oiler cam shaft rotates in a clockwise direction.
Looking at the interaction of the cam shaft and the cam plate, when the cam is rotated clockwise, it pushes the cam plate to a more vertical position. This means the pistons move less in their bore, and pump less.
This seems the opposite of what the pump should be doing, more oil at high speeds.

When I have worked on hydraulic pumps, the more angle on the swash plate, the higher volume of oil is pumped.


Am I missing something here.

Cheers,
Mick

[Steve Swan]

Thank Mick, for your post. I'm glad to see you are studying the '29 oiler function. i didn't get a chance to inspect or work on my buddy's '29 oiler; he did that himself. So, i'll be interested to hear your thoughts. If Tommo sees this, hopefully he will. Or Mark Masa.