Oil Bath Filter Modification

The old and reliable.

Yard Art
Yard Art

Posts: 56

Joined: Mon Sep 04, 2017 6:22 pm

Post Wed Nov 01, 2017 6:09 pm

Oil Bath Filter Modification

I am sure there are many ways to do this, but this is what I did. I wanted to keep the look of the factory oil bath air cleaner without using the oil. An aftermarket open element paper air filter type air cleaner had been installed on the truck when I got it and the oil bath was tucked in a box of parts. So my goal was to get the factory look of the oil bath air cleaner but use a more common paper air filter. I was able to combine parts from the aftermarket paper set-up and do some modifications to the oil bath filter to get it all to work.

I first tried to fit the paper filter down into the base of the oil bath housing just to see if it fit. Sure enough it did, so that was the spark for my project. The paper air filter is a NAPA Gold #2110 filter which measures OD- 6 1/4"; ID - 5"; Height - 3"

Pic #01 is an adapter I made to lengthen the oil bath stud and use the brass fitting that was used to hold down the top lid of the paper element air cleaner - not factory, but I liked it. The inside threads of the brass fitting was the same as a number 10-32 screw so I bought a small box of screws at 1" long. I used a 1/4" x 2" roll pin that I opened up both ends slightly with a chisel so the 10-32 screw would fit inside tightly as well as the oil bath base stud.
I cut the head off the 10-32 screw and jammed it into one end of the roll pin - abou 1/4". I inserted the paper filter into the base, its lid on top, and then loosely fit the roll pin on top of the oil bath base stud. (NOTE: Prior to installing the lid on the paper filter, I had to enlarge the hole in the lid so it would slide over the roll pin when you pull it off) Next I set the oil bath filter/top down over the roll pin/screw and on top of the paper filter/lid. My 10-32 screw stuck up through the top of the oil bath filter and I screwed the brass fitting down onto it until the screw was flush with the top of the brass fitting - just like it would be if I were tightening down the oil bath filter element to make it secure. The brass fitting screwed down stuck up above the top of the oil bath filter leaving a gap underneath, so I tapped it down with a hammer to seat it down over the stud of the oil bath base and to seat it on the top of my oil bath filter. This seated the roll pin over the oil bath base stud to get the correct length I needed for my new hold down stud to stick out of the top so I could screw the brass fitting down to secure it. (I could have used a threaded rod and removed the stud from the oil bath base and welded it in place, enlarged the hole in the oil bath top to match the threaded rod, and inserted it through the oil bath filter/top, and then cut as needed. Was easier for me to work with what I had.) I then removed the brass screw and lifted the oil bath filter/top, air filter lid, & air filter from the base. My new hold down stud was now at the correct length.

Pic #02 is another view of the modified stud and the oil bath base after I removed the oil bath filter, paper air cleaner lid, and paper filter. I then pulled out my torches and welded the 10-32 screw and base stud to the roll pin -old school using a coat hanger for my filler rod. Got it all welded together and it ain't going to move.

Pic #03 is the underside of the oil bath base which sits over the Zenith carb. The paper air cleaner had a steel compression ring/clamp that gets tightened down to clamp the air cleaner to the carb. Th oil bath base did not have anything to hold it in place on the carb. So I broke the spot weld holding the compression ring/clamp to the paper air filter base and used it on the oil bath base, BUT I had to cut slots into the oil bath base so as they would collapse when the compression ring/clamp was tightened down.

Pic #04 shows the slots I cut into the oil bath base using my die grinder and cutting wheel. You can see the compression ring/clamp installed as well. I had to cut the slots 1" deep as measured from the inside radius of the neck that fits over the carb. Had to go this length in order for the clamp to squeeze in on the oil bath base and secure it to the carb.

Pic #05 is the NAPA Gold # 2110 paper filter set inside the oil bath base. Fit pretty good. Then I install the metal air cleaner lid slipping it over the roll pin. There is a slight gap between between the oil bath stud and the slightly enlarged hole in the metal lid. My thoughts are to either use a small piece of foam/sponge and slide it down over the stud on top of the lid or possibly an O-ring. Yet to do this.

Pic #06 is the oil bath top element set on top of the paper air filter and tightened down using the modified stud and the brass fitting to secure it. If your new stud does not quite stick up enough to screw on whatever hold down nut or wingnut you use, you can place the oil bath filter on a flat surface and give it a little even downforce and collapse the bottom just a little - I had to do this myself.

Pic #07 is the top showing the brass fitting (looks like a thumb wheel of sorts, but I thought it looked good being brass).

Pic #08 is the air cleaner assembly on the engine. To me, it looks original, but uses the paper air filter which I prefer over the old oil bath style.
01 KB5.JPG
02 KB5.JPG
03 KB5.JPG
04 KB5.JPG
05 KB5.JPG
06 KB5.JPG
07 KB5.JPG
08 KB5.JPG

Rusty Driver
Rusty Driver

Posts: 199

Joined: Sun Feb 24, 2013 11:31 am

Location: Long Island, NY

Post Tue Nov 14, 2017 8:03 am

Re: Oil Bath Filter Modification

Thanks for posting. Wouldn't a coupling nut and threaded rod be easier than the roll pin method? No welding required.
User avatar

Golden Jubilee
Golden Jubilee

Posts: 1575

Joined: Thu Nov 29, 2012 10:40 am

Location: Wichita, Kansas

Post Tue Nov 14, 2017 11:58 am

Re: Oil Bath Filter Modification

Years ago someone posted a similar thread. He poured epoxy resin into the bottom and let it harden to make a flat surface for the filter to set on. Just another idea.

Lifelong Kansan
Grew up with red paint
Moved off the farm 26 years ago.

Freshly Restored
Freshly Restored

Posts: 251

Joined: Sat Dec 01, 2012 9:55 am

Post Tue Nov 14, 2017 5:26 pm

Re: Oil Bath Filter Modification

Yard Art
Yard Art

Posts: 56

Joined: Mon Sep 04, 2017 6:22 pm

Post Tue Nov 14, 2017 6:30 pm

Re: Oil Bath Filter Modification

Boobtube wrote:Thanks for posting. Wouldn't a coupling nut and threaded rod be easier than the roll pin method? No welding required.

My local supply store where I get my bolts/nuts/screws, etc. did not seem to have a coupling nut as I did look, and I have never seen one that small a diameter - seen larger bolt size couplers. I also think a coupling nut would be larger in diameter and you would have to make the hole in the paper element lid a little larger, but really no big deal. You would also have to make sure you used some kind of epoxy or locktite so there would be no chance of something backing off and falling down the intake.

Again, worked with what I had and the welding part of it is what I can do and it ensures the pieces won't come loose.

Return to K and KB

Who is online

Users browsing this forum: No registered users and 1 guest

Powered by phpBB® Forum Software © phpBB Group
Designed by ST Software for PTF.