The Stovebolt Site Forums The Shop Area Engine Shop Oil bath Air filter

Hi there,

I have a question for the folks with the old school oil bath air filters. Can anyone tell me how they work, and where I could get a replacement screen?

I am a truck novice fixing up a '54 Chevy and I would like to keep the original air liter. Does it make sense to hold onto it or just put a current one in?

Thanks for help.

Carlos

Welcome, Carlos.

They worked by drawing the intake air through an oil-saturated mesh. There should be a cutaway picture in your service manual. A popular mod is to replace the oil bath stuff with a modern paper element. This lets you keep the original look, with an easier to service air filter.

If you don't have the shop manual yet, here's a link to the online version that'll get you started.

regards,
Leon

Thanks Leon. Any idea where I could get replacement mesh? Jim Carter does not seem to carry the metal mesh.

hmm, im still not too sure how well this works. but its what i used, a coarse steel wool seemed to work pretty well. hope this helps! and good luck with your truck!

I went to WalMart and bought the coursest steel wool they had and it worked great.

If you are dealing with a true oil-bath air cleaner, they use a pool of oil in the bottom the air cleaner pan. The mesh above the pool should be wetted with oil, but it is mostly a 'bug catcher.' The actual dirt capturing takes place by the change in direction of the air flow, from down to up, that takes place above the oil pool. Dust, etc. contained in the incoming air has a higher inertia than the air itself, so the incoming dust dives, so to speak, into the oil. Oil bath air cleaners have a slightly higher pressure drop than do paper elements because of the reversal of the air path, but for applications other than in racing engines, the difference is insignificant. Oil bath air cleaners have to be cleaned every couple of thousand miles or so, depending on operating conditions, but do not fill the oil pan above the "fill" level. Usually, there is a mark or arrow indicating the full level, but if not, typically there is a rim a little way above the bottom of the pan that is the 'fill' level. The OEM air cleaners are marked pretty clearly. If you put too much oil in the pan, you risk pulling oil into the engine and having a lot of smoke- or worse.

Also, use a fairly heavy oil in the air cleaner pan; SAE 30 was typical in the past, but a heavier grade is alright. Light/thin oil may be pulled out of the pan by high air flow.

Paper filter elements typically are a little better at capturing small particles, but oil-bath air cleaners did a good job when maintained properly.

Harvester

http://en.wikipedia.org/wiki/Air_filter#Oil_Bath

GM recommended SAE 50 oil in oil bath filters, at least for 47-63 6-cylinder engines.

Thanks for the responses everyone. Sounds like I need to get some oil and that the steel mesh I have is in pretty good shape.

Cheers,

Carlos

Thanks for all the information Harvester!

kendall makes a low price sae 50 that seems readily available.