Ironhead Ironhead Oil Pump Gurus, come inside.

[THEWILDONE]

Some of you may know, that I have been slowly working on putting my UL Harley back on the road.

One of the things I did while I was rebuilding the flathead was to adapt an IH oil pump to it.

I followed along with this guy's writeup:
https://dicklinn.webs.com/

Well, I just put oil in the tank for the first time since getting it all back together and I'm seeing a pretty fast leak from the IH oil pump.... I tightened the nuts that bolt it to the case and stuck a catchcan under it to see how much it leaks when I check on it later......

If I have to pop this pump back off and fix (slow) the leak I'm hoping to get some information from people that are knowledgeable on these IH oil pumps and what might be done to get them to stop leaking.... I mean at least slow down, I certainly don't expect a 1937 Harley not to leak at all!

I used the factory style IH gaskets on the oil pump. One of them I actually tossed and made my own becuase it just didn't line up.

The engine hasn't even been run yet and when I put oil in the tank it started leaking at the pump like a sieve.

Here's what I do know (I think):

The pump body and associated parts are free from cracks.

I took the time to block sand the breather tower, the pump body, and the bottom cover for the pump in an effort to make everything nice and flat.

In the event that this leak doesn't slow down and I have to take the pump back off and address this, what might I try to slow or stop the leak?

[bustert]

assuming external leak through flanges, and not weeping out the drive or check?
those gaskets are .002 thick and it does not take much to make them leak. you might try a flange sealer on them or caterpillar gasket cement.
if it have to deck something like that or a cover, i use a sheet of glass and clover compound.
there is a little trick to block sanding most do not know about and it will screw a surface up, at least on a guitar body so i assume it would do more or less to a soft metal.
when you block sand, make sure the paper does not round up around the side, it it does, that edge will see the action first and cut too deep, the trick is to glue the paper to the block and then trim flush all around. you can make various sizes using hard wood.
i would have to take a look at a body to see if possible but another option is machine o-ring groove and use spaghetti o-ring material of proper size.

[Ferrous Head]

SOME if these have a very small dowl pin. If you try to mix and match covers. towers and bodies you can run into this problem. If the dowl pin doesn't have a corresponding hole in the plate the pump will/would leak like a sieve,
There are several different versions of this pump which require different versions of gaskets. You might need to buy a half dozen gaskets before you hit ones that fit correctly. Some have not been cut correctly and will bind they gears.

[Serious Blac]

I asume that what you call "block sanding" is known in engineering as lapping. If so then a figure of eight motion should be used to even the material removed.

[bustert]

super duper +1 mr.ferrous
totally forgot that one, the very reason when you buy a pump kit it has several gaskets so you have to pick the right one.

[needspeed]

Hi Bustert and Ferrous Head,
From your responses so far I get the feeling you haven't read the link provided by the OP in post 1?

Check it out. This is an extensively modified pump with many more areas for potential leaks than what we're used to with our stock ironhead pumps installed on the engine they were designed for.

One area that got my attention was the drilling of a mounting bolt hole through the pumps feed channel.

THEWILDONE, Can you pinpoint were the oil is leaking? It must be significant if it leaks like sieve without the engine running.

[THEWILDONE]

Thanks for the input guys.

After tightening the 4 dome nuts down some more and leaving the catchcan underneath it, I can report on the leak.

It looks like, after tightening down the nuts and leaving it to sit for a while it's leaking maybe about 1 OZ or so in a 24-48 hour period.... Not bad considering it's a Harley from the 1930s, with an oil pump from an IH stuffed onto it.

It looks like now, that most of the remainder of the leak is coming from the 4 studs on which the oil pump mounts via the dome nuts. I might try sticking some fiber washers and/or O rings under the nuts and see what that does

As needspeed mentioned, we're dealing with a "unique" situation here.

It looks like, at this point at least, after sticking inspection mirrors under there and studying it that most of the oil that is leaking now is coming from the 4 mounting studs. But like I said, it's maybe 1 OZ in a 24-48hr period so that could be tolerated, all things considered, and/or I might experiment with some additional means of sealing at the mounting studs.

Stay tuned!

[spacecoast]

NeedSpeed --"the drilling of a mounting bolt hole through the pumps feed channel."

This bothered me as well.

The wildone -- " I might try sticking some fiber washers and/or O rings under the nuts and see what that does"

I thought fiber washer and I also thought maybe crushed copper washers.

The mounting studs. Are they threaded coming through the pump body? I'm thinking if it's threaded where it protrudes for a washer and nut, than you'll have a heck of a time sealing that one stud. Maybe a longer stud so that the shank just needs to be sealed as opposed to the threaded section of the stud. That was an interesting read Wildone, thanks for the link.

[Ferrous Head]

is leaking now is coming from the 4 mounting studs

Very obviously I am missing something here. I thought we were dealing with IH pimps which have 5 mounting studs not 4.

[spacecoast]

Originally Posted by Ferrous Head

Very obviously I am missing something here. I thought we were dealing with IH pimps which have 5 mounting studs not 4.

For his adaptation, only four are used.

He hasn't posted a pic yet, so I'm going off of Linns website.
If he has the room (frame clearance for instance) he would be better off using a bolt at the rear inside mounting hole. As it is now by using studs, I think he's fighting sealing those threads. Like how a wet clutchers primary adjuster leaks.

More interesting info.

http://victorylibrary.com/tech/Frankenstein.htm