How does an oil bath air filter work

[stude62]

Saw on ebay where a 55 Champion with an oil bath airfilter was converted to a paper filter system.

How does an oil bath system work?

Stu K


'63 Lark Regal, "Miss Rose"

[Lark Parker]

(My theory) is that it is a bit like a centrifuge and as the air makes the down-and-back-up turn the dirt particles fall, or are slung out, and the sticky oil captures them.

This was probably adapted from an old American Indian trick of forcing running buffalo into a tight turn where the biggest, fattest ones couldn't corner as well and went to the outside where they could be slain (or captured in 30 weight non-detergent oil).

Lark Parker

Just an innocent possum strolling down life's highway.

[hotrodstude]

first the air filter element is a steel or fabric mesh which is reuseable. you wash the filer element(usually with gas or some other cleaning fluid) blow it out with compressed air reinstall in housing the soak th e element with motor oil usually 10w. install lid and your ready to go. the dirt will stick to the oil on the element. needless to say you had to clean to filter more often th e the dry element.alot more work than dry filters.need to drain excess oil from filter housing also.

2006,f-150,2x4,v-6,5-speed manual,8ft bed,

[Warren Webb]

While oil bath air cleaners had fallen from grace of the OEM market their benefits are seen now coupled with more modern filter elements in the form of ones like K&N.

60 Lark convertible
61 Champ
62 Daytona convertible
63 G.T. R-2,4 speed
63 Avanti (2)
66 Daytona Sport Sedan

[Milaca]

To further detail Lark Parker's explanation, I found the following explanation at the Wikipedia website.

"An oil bath air cleaner consists of a round base bowl containing a pool of oil, and a round insert which is filled with fibre, mesh, foam, or another coarse filter media. When the cleaner is assembled, the media-containing body of the insert sits a short distance above the surface of the oil pool. The rim of the insert overlaps the rim of the base bowl. This arrangement forms a labyrinthine path through which the air must travel in a series of U-turns: up through the gap between the rims of the insert and the base bowl, down through the gap between the outer wall of the insert and the inner wall of the base bowl, and up through the filter media in the body of the insert. This U-turn takes the air at high velocity across the surface of the oil pool. Larger and heavier dust and dirt particles in the air cannot make the turn due to their inertia, so they fall into the oil and settle to the bottom of the base bowl. Lighter and smaller particles are trapped by the filtration media in the insert, which is wetted by oil droplets aspirated there into by normal airflow.

Oil bath air cleaners were very widely used in automotive and small-engine applications until the widespread industry adoption of the paper filter in the early 1960s. Such cleaners are still used in off-road equipment where very high levels of dust are encountered, for oil bath air cleaners can sequester a great deal of dirt relative to their overall size, without loss of filtration efficacy or airflow. However, the liquid oil makes cleaning and servicing such air cleaners messy and inconvenient, they must be relatively large to avoid excessive restriction at high airflow rates, and they tend to increase exhaust emissions of unburned hydrocarbons due to oil aspiration when used on spark-ignition engines."



A wild Red Hawk admiring it's reflection.
In the middle of Minnestudea

[PackardV8]

quote:How does an oil bath system work?

Quite well, actually. The principal reason they were discontinued is the taller they are, the better they work. As mentioned, the air column enters moving downward. When the air makes the sharp 180-degree turn at the bottom, the dirt continues into the oil and is held. As car hoods got lower, there was no room for the tall oil bath. The paper filter was developed because it would fit better (and cost less).

thnx, jack vines

PackardV8

[BobPalma]

Agreed on "all the above" explanations. (To add to Lark Parker's pontifications: Indians did not eat much turtle soup because they could get the turtles to run fast enough to be flung off in the tight corners.)

On a more serious note, Dwain Grindinger was in the Pacific northwest when Mt. St. Helens spewed all the ash into the air during its famous 1980s(?) eruption. Dwain reported dry-element air cleaners being nowhere near as effective dealing with that ash as were oil-bath types. [8D]BP

[Studebaker Jake]

They are quite restrictive, but i think they still use them on tractors and construction equipment and such. They can trap a large amount of particulates without needing attention. Just remember not to hold it on its side while messing with the carb.

[PackardV8]

quote:They are quite restrictive

Just wondering on what reference data source that statement is based?

I'm looking for the old article, but IIRC, way back in '56, the Cadillac, Chrysler and Packard V8s with the 2x4bbl option used BIG dual oil bath air cleaners set off to the outside of the rocker covers.

The Corvette with 2x4s used two small chrome paper air filters.


The big car guys who wanted to look racier traded their oil baths for the Corvette paper filters and went slower. The oil baths were actually less restrictive, but couldn't be used because they wouldn't fit under the Corvette hood. Notice the later Corvettes used the much larger single filter element to try to eliminate the restriction

thnx, jack vines

PackardV8

[Mark57]

I agree that oil bath air cleaners work better than paper, just a little more maintenance and trouble, but I had VW's into the 1970's that still used them. And of course, on most trucks, clearance isn't a problem!


<h5>Mark
'57 Transtar Deluxe
"Star Performers with Saving Ways!"

Vancouver Island Chapter
http://visdc.shawwebspace.ca/ </h5>

[StudeRich]

Wow! AIR Brakes with a water heated Compressor! That is one Heavy Duty Stude. "C" Cab (Transtar?), used in a dusty climate, it definitely NEEDED that good Oil Bath Air Cleaner! [^]

StudeRich

[lark55]

One of the first jobs I had was as an "oiler" on a rock-crushing operation. Part of my job was to change the oil and service the oil bath filter on the diesel power plant each week. The oil bath filter would typically have about a quarter inch of muck built up in the bottom of it.

[Mark57]

quote:Originally posted by StudeRich

Wow! AIR Brakes with a water heated Compressor! That is one Heavy Duty Stude. "C" Cab (Transtar?), used in a dusty climate, it definitely NEEDED that good Oil Bath Air Cleaner! [^]

StudeRich

It's a local truck owned by Rob Hill. It is an 8E40C-171 Transtar. It is one of the 35 USMC units produced by South Bend in 1963. Here is the whole truck...


<h5>Mark
'57 Transtar Deluxe
"Star Performers with Saving Ways!"

Vancouver Island Chapter
http://visdc.shawwebspace.ca/ </h5>

[Milaca]

It looks like a tall step up into the cab on that truck. Did Studebaker offer running boards as an option for these heavy trucks?

[Mark57]

quote:Originally posted by Milaca
Did Studebaker offer running boards as an option for these heavy trucks?

Yes, AC-3267 (right) and AC-3268(left).

<h5>Mark
'57 Transtar Deluxe
"Star Performers with Saving Ways!"

Vancouver Island Chapter
http://visdc.shawwebspace.ca/ </h5>