VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 1934 master Air filter

I am now going to clean up and paint my air cleaner (1934 master).... it has the copper mesh in it and I know that I need to soak that mesh in kerosene, or maybe lacquer thinner.... then soak the mesh in about 50W oil.... but is the bottom bowl shaped area below the mesh cage, supposed to have any oil puddled in it...??? in other words .... was the 1934 master air filter, an OIL BATH filter...??? attached photos....

That is the optional oil bath air cleaner........usually found on cars of the dust bowl of the 1930s area.

OK Gene... that is where the car came from, (eastern Colorado).... the entire car was coated in dust glued to metal with oil...
I literally had to chisel the dust/oil globs off of the entire undercarriage...... So my question is still not answered... do I pool a small amount of oil in the bottom of this air cleaner..... I have 18 miles of dusty dirt road ... as my driveway, just to get to the pavement. So, it will need the 'dust bowl' air cleaner.... it is either dust or mud, depending on the weather... it will be my 'daily driver' that I drive to town once a week...... is it DESIGNED to HOLD some OIL in the bottom....??

The picture in the shop manal shows a different looking air cleaner,,,,,Is there an oil level mark with lettering in where the oil would go? If nnot It looks more like what is in a later manual and says 1 pint of #50.

Yes... after cleaning it up today.. I see where the oil level is marked on the inside.. looks like it will take about a pint to bring it up to that mark... thanks Gene It should be a good air cleaner for the dirt roads it will drive on...

While Gene is most likely correct in suggesting #50 oil most engine oils will work just as well.
Tony

The factory always recomends #50 for all years and a lighter oil in the winter. The reason for #50 is it is lesslikely to slosh around during starting,stopping etc.
For my cars I used straight #40 because that is what I had it stock.

Would someone explain just how the oil bath air filter works. Thanks

Dick

Oil bath air cleaners used a multi stage process to do the job.
Nearly always the air was first directed downwards towards the oil in the oil cup, where it then had to turn upwards into the mesh in the filter body.
The centrifugal force generated during that turn threw most of the dirt in the air immediately into the oil in the cup.
Also, as the air was being forced to make that turn by the oil in the cup, the air picked up some of that oil and carried it up into the mesh in the filter body.
That oil got caught by the mesh before it could make it through to the engine.
So then the air wasn't just passing through a mesh, it was passing through an oily mesh.
The remaining dirt in the the air was then caught by the oil hanging on the many many edges it had to make it's way through on the way to the engine.
As the oil was being continuously carried up into the mesh, the mesh became saturated and unable to suspend it all, so gravity pulled the dirty oil back down into the oil cup.
As the oil in the cup became laden with dirt, the dirt settled out to the bottom of the cup leaving "cleaner" oil at the top to continue the whole process.

Hope that helps! :-)

Oil bath air cleaners were used in agriculture by manufacturers such as John Deere at least up into the early '60s when dry elements became the norm.
Air cleaners have a huge job to do on tractors, and especially so on combines... and I've dumped, washed, and refilled them with clean oil on more mornings than I can remember.
Over the years Deere's recommendation for the oil to use in the bowl pretty much followed "use the same weight as used in the engine".
Also over the years, their recommendation for the engine oil (and therefore the air cleaner) got lighter and lighter.
By the early '60s, that meant using a 20w-20 or 10w-30 oil in the engine and air cleaner.
EXCEPT under very dirty conditions... then, 10w oil was recommended in the air cleaner bowl.
The reason for this was that lighter oil is more easily picked up by the air passing over it, and more oil is circulating up into the mesh and draining back down, therefore doing a better job of cleaning the air.
For this reason, I've always used light oil in ALL of my air cleaner bowls, including my '46.

Also of interest...
When high detergent heavy duty oils became popular, some sources said not to use them in air cleaners as they might foam and not work properly.
After some time and experience, Deere issued service bulletins saying the heavy duty oils were fine to use after all.
In fact, they were better, as they wash the mesh in the filter body cleaner.

One final thing...
Don't be tempted to think that over filling the bowl will make the air cleaner work better.
It won't.
In fact, dirty oil can be carried straight through the mesh and into the carburetor if this is done.
Over filling will do this, but using light oil will not, and I have verified that it will not by examining the top of the mesh on my '46 when servicing.

Great information about oil bath air cleaners. Thank you Ole!

One tricky point to remember. When you remove an oil bath chair cleaner from under the hood of a car, keep it as vertical as you can. Don’t ask how I learned that lesson.

The other advantage is when the oil sloshes up on the filtering mesh, the mesh gets automaticaly cleaned.

All modern oils contain silicone to prevent foaming.

Perhaps GM recommended #50 oil was due the the higher closed under hood temperature in car and truck engines.

Thank you Ole. That explains it to me in easy to understand verbiage.

Dick

I have filled the bottom of the oil bath filter with 20W-50W oil... and saturated the copper mesh.. and let it drain then installed it.... the 20-50 weight oil should work well in hot or cold weather...

Good, that wil keep everyone happy..