Knuckle Extrernal Oil Filter

[billpedalino]

I'm installing an accessory OEM oil filter on my '47 and have four questions for anyone who is running a filter on his/her knuckle:

1. I've seen old factory accessory ads showing the external oil filter fitted to the knucklehead, but don't know when this accessory became available. I would assume it was after the 1948 introduction of the unsupported external panhead filter. However, given the bent bracket that attached the filter to the rear knuckle rocker box, it might have come about in 1950 or so, after the panhead support bracket was introduced and modified as a bent plate for use on knuckleheads. After further obsessive thinking I then thought that maybe the filter predated the panhead's introduction - but the filter does have a -48 P/N, so probably not. Does anyone know when this option was first available for knuckles?

2. I seem to recall that the bent bracket that attached the filter head to the knuckle rocker box was parkerized. Please confirm as I don't have one and will either have to make it or buy & modify one and most likely parkerized it.

3. Oil pump return line P/N 63500-50 supposedly fits all models for 1941 through 1950. As the pump cover changed in late 1950, I'm assuming its correct for the cast iron rotor-type pump cover. Please confirm.

4. Finally Oil Line fitting p/n 63526-50 Appears to be for the later 1950 oil pump cover. How does the return line attach to the cast iron cover? There must be another return line for 1948 through early 1950, as the filter was used as an accessory on the 1948 and 1949 panheads which had the cast iron covers.

Thanks,
Bill Pedalino

[Chris Haynes]

The bracket attaching the oil filter to the Knuck rocker box tab first appeared in the 1950 accessory Catalog. The previous set up where the oil filter attached to the oil tank was abandoned because they were tearing the nipple out of the tanks.
The bracket was Parkerized.

[Rubone]

All the brackets in every kit I have seen are cadmium plated. Never seen a parkerized one. I had a black painted one once but it turned out to be a homemade repop.

[billpedalino]

Chris,

Do you have the accessory catalogue illustration (that I've seen somewhere) of the oil filter installed on a knucklehead? I'm having my '47 judged again in August and want to have some backup with me showing that it was a dealer-available accessory prior to 1947.

Also, all the external knuckle filters I've seen were installed on bikes with rear cross-over pipes. Mine is a single muffler model that required that I fabricate a custom-bent head bracket and oil pump return line in order for the canister to clear the rear exhaust pipe. The installation looks great and I'm wondering if you've ever seen this filter installed on a single muffler machine?

Also, there is some ambiguity about the parkerized acorn nuts that I have on the springer return spring studs. Bruce Palmer implies that they were parkerized in '47, but the previous judge questioned them stating that they might be cadmium. Would you know definitively?

Thanks,
Bill

[Rubone]

The Knucklehead filter kit was a retro item and became available in 1950, and never existed in '47. It first appears in the '50 accessory catalog. In the '49 catalog the only one listed is the -48 type for '48 up BT. Keep in mind that the late '48,'49, and early '50 filter screwed directly to the oil tank, no mounting brackets and a solid cap. The through bolt with the matching cap was a new for '50 part and kits were sold to convert earlier filters to the new type. The original type broke oil tanks. All filter kits sold for Knuckleheads were retro fit, and there is no mention of filters in either the '47 or '48 accessory catalogs.

[rudy]

I put NOS kit on a 47 single muffler bike, Don't remember having any fitment problems. Since
sold the bike......i still have a small bag of fittings i didn't use and probably never will if anyone needs them.
my head bracket was cadmium.

[cdndewey]

I put NOS kit on a 47 single muffler bike, Don't remember having any fitment problems. Since
sold the bike......i still have a small bag of fittings i didn't use and probably never will if anyone needs them.
my head bracket was cadmium.

I'd be interested in them if they aren't spoken for.

[rudy]

Send me a pm with your phone number and ill send you pictures. Don't have a computer,

[Chris Haynes]

Dennis Corso makes all the lines and fittings.

[billpedalino]

I just went another round with this darn filter. I see no way that this will fit a single exhaust machine given the parts that I have.

I have a set of oil lines from Ted (which are useless) as well as the set from Old Dude which are much better. I also have Ted’s head-to-filter bracket which, as expected is also so far off it’s not worth commenting upon. However, even without using a mounting bracket, this interference with the rear pipe is a significant problem. Even when mounting the filter assembly just on Clete’s oil lines the pipe is in the way of the canister. The oil lines also appear to be just a little short - but maybe I'm wrong on this point as things aren't lining up at all and Old Dude's stuff is generally very good. Also, the inlet fitting in the filter head looks like it's angled slightly backward toward the oil pump. Is this correct or are my threads buggered?

As for the mounting bracket, I’ve been trying to heat-bend a bracket that works from ¼” stock, but no matter what I come up with, the exhaust clearance remains a problem. Also, because the small oil line radii are tighter than the minimum 1” for 3/8 tubing, I assume that these lines are machine-mandrel-bent. As I’m no longer in the motorcycle business, this is a process that I can’t perform so making up a set of lines that look somewhat OEM isn’t an option for me.

Now the questions:
• Does anyone you have a correctly bent head-to-filter bracket (preferably OEM)? If not, does anyone know where I can find one other than Taiwan scrap metal?
• I know that I asked this above and I certainly don't mean to be disrespectful to Rudy, but are we certain that this 1950 factory kit was available for single exhaust knuckleheads or was it only meant for dual exhaust knuckleheads? I just can't see how it will work on a single exhaust machine unless my oil lines are very far off.

Thanks Again,
Bill Pedalino

[Rubone]

H-D built the kit.
There was no such thing as a dual exhaust Knucklehead ever built by H-D.
H-D did not make stuff to fit with aftermarket parts.
If they fit a Panhead, they fit a Knucklehead, all the exhaust parts are in the same place and the brackets locate the filter in the same spot.
Why don't you post a picture of what you are trying to do?

[1950Panhead]

• Does anyone you have a correctly bent head-to-filter bracket (preferably OEM)? If not, does anyone know where I can find one other than Taiwan scrap metal?

I posted a photo on caimag so you can see the bracket.

• I know that I asked this above and I certainly don't mean to be disrespectful to Rudy, but are we certain that this 1950 factory kit was available for single exhaust knuckleheads or was it only meant for dual exhaust knuckleheads? I just can't see how it will work on a single exhaust machine unless my oil lines are very far off.

I looked in the 1950 parts catalog, I don't see any oil lines for mounting a filter on a knuckle.
The knuckle filter is closer to the air cleaner to clear the exhaust.

[billpedalino]

Thank yo Gentlemen,

Robbie - what you stated makes sense - Harley would not make an accessory that didn't fit its own design and the crossover exhaust was indeed an aftermarket item.

1950Panhead - I can see why the filter would be quite close to the air cleaner. However, this causes the 'S' oil line (filter to tank) to be too short. This is the case with Ted's and Old Dude's oil lines.

I don't think this is a a pipe geometry problem, as there's not much room for deviation there I'm using Dennis Corso's rear exhaust pipe which fits quite well, but I had the same clearance problem with an old Dixie pipe as well. I'm also running a chrome pipe cover which fits tight to the pipe. Maybe that's contributing to the problem.

If both oil lines were just a little longer I think I could make it work with some more bracket-bending. It would be much simpler it I had the OEM mounting bracket! - Does anyone have one to sell or trade?

I'll try to take some pictures today.

[bobphd]

Bill, I run this filter setup on 3 of my bikes. 2 are OEM brackets and 1 is a teds repop. All 3 brackets I had to a little tweaking to get the filter in the right spot and angle. Actually less on the repop than the originals. I tryed using Dennis Corsos lines but like you found them just a little short. I bought line from McMaster Carr, bent it to the exact shape and length and then had it cad plated. The filter does have to be in a pretty exact spot And if you are running chrome stack covers as on my 47 it is difficult to get it right. Bob

[billpedalino]

I have no idea if I uploaded these photos correctly, as this process is a bit user-hostile!

If I was successful you will notice that when holding the filter somewhat vertically and close enough to the exhaust pipe to afford clearance, the 'S' line (filter-to-tank) appears to be about 1/2" too short. If I move the filter backward (toward the rear of the bike) and out (toward the right side) far enough to miss the exhaust pipe, the other oil line (oil pump to filter) is about 1/2" too short and must also be further bent to compensate for the filter movement toward the right. Also, from experience, bending these lines with a manual bending tool leaves divots in the tubing and other marks. Until I get the oil line geometry worked out, I can't bend (yet another) mounting bracket.

Also, the 'S' lines that I have are shown in the attached photo. The one on the left is from Old Dude. The one on the right is from Ted and is shorter than Clete's and has a different bend. The Old Dude line is closer, but still too short for my application.

This shouldn't be so complicated!

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