OIL BATH AIR FILTERS
- Thread starter thiggy
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Depends on what you mean by "effective".
For pure filtration purposes, nothing beats paper. It has the smallest pore size and filters out the smallest particles the best.
If you want air flow, then the oiled elements seem to flow better. Although the claim is that they actually filter better because of "molecular attraction" to the oil, I find this, um, suspect.
The reason so many off-road vehicles use oiled filters is that they have the ability to move air under severely adverse conditions, such as really dusty or dirty air. Also, they have the ability to deal with water much better, as well (remember the old paper filter Husqvarna's? great desert bikes but don't get 'em near rain or a water source...).
This is the raging debate and IMHO there is no one right answer. I think it depends upon what you application is, and what is important to you.
Best of luck.
Bob W.
I assume by oil bath you mean the old fashioned, oil in the air cleaner oil bath?
They served tractors and older vehicles in very dusty environments well, as long as they were cared for properly (cleaned and changed). I have one on my refurbished 1947 Ford 2N tractor, and it catches a LOT of dirt. That being said, I would never run one on a newer vehicle. I don't know any numbers or specifics, but while they probably filter pretty good, I wouldn't risk a modern engine with an old technology filtering system.
I would think that the paper probably filters smaller particles far better, since the oil bath cleaners used a steel wool-like mesh to filter the small stuff.
Just wanted to add that many vehicles including the Toyota Land Cruiser sold here in India as have their paper filters replaced by oil bath type for better filtration. India's Rajasthan dessert is notorious for spreading really fine sand all over its neighboring areas which incudes the capital Delhi. I have seen Land Cruisers in Middle East as well as in Australia with the same antiquated oil bath filter, has to be a reason for companies to put these filters.
My understanding is that the paper filters have been enforced to meet pollution concerns as the oil bath filters have to dispose of the dirty oil raising concerns for improper disposal.
The other factor is that oil bath filters, if not maintained properly will start passing the dirt stuck in them where the paper filter will just clog up and stop passing air altoghether leading to engine performing poorly.
My understanding is that the paper filters have been enforced to meet pollution concerns as the oil bath filters have to dispose of the dirty oil raising concerns for improper disposal.
The other factor is that oil bath filters, if not maintained properly will start passing the dirt stuck in them where the paper filter will just clog up and stop passing air altoghether leading to engine performing poorly.
Could be that in some of these dry, dusty climates the filter will be needing frequent cleaning or changing. Oil bath can be cleaned and reoiled most anywhere. Hopefully the people will dispose of the oil properly.
Under these circumstances an oiled filter would probably make more sense, as the sand will likely clog a paper filter more quickly, and the oiled filter would allow for both filtration and breathability (if that is a word).
I think one question has to be asked anytime that the issue arises between paper versus oiled elements: has *anyone* ever suffered an engine failure when they have properly used either one of these types?
Bob W.
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I don't know about the "molecular attraction" of the oil (maybe you have to use "Start Up" to coat the filter
I think paper wins hands down in all conditions. I'd bet the conversion to oil bath in any third world country is an economic one. Labor and low grade oil cheap, filter elements expensive.
Any body have a used oil analysis from an oil bath filtered engine.
I suspect widman (member #22) may be our man on this subject.
[ September 26, 2004, 10:07 PM: Message edited by: Neil Womack ]
Any body have a used oil analysis from an oil bath filtered engine.
I suspect widman (member #22) may be our man on this subject.
[ September 26, 2004, 10:07 PM: Message edited by: Neil Womack ]
I thnk you're right. The people running multi million dollar off road construction equipment and military combat vehicles in conditions where you can't see 10 feet because of the dust aren't all stupid. They use paper elements, more correctly paper type elements.
What about oiled cotton?quote:
Originally posted by TheFuror:
Another one is that, to my knowledge, every off-road motorcycle, whether a desert sled, motocrosser or cow trailer, currently uses an oiled foam air cleaner in lieu of a paper one.
Bob W.
oiled Foam clogs way to quickly, 90% of the motocross sports, especially dirt bike dessert racing uses K&N or equivlent.
See, now I get to show my age: oiled foam is what all the dirt bikes used, back when Roger DeCoster was champ and Bob "Hurricane" Hannah won on a box stock Yamaha YZ 250.
I checked out the online parts catalog for a 2005 YZ 250 and it appears to be a foam filter as well.
However, I will defer to RW4k on what the newer riders and/or factory teams use for aftermarket items. I suspect that in this application, K&N and/or oiled cotton would work well.
Besides, Mama says I am too old to buy one of these newfangled motorscooters anyhows.....
Bob W.
Well, it does attract dirt.quote:
Originally posted by Gary Allan:
I don't know about the "molecular attraction" of the oil (maybe you have to use "Start Up" to coat the filter) ..but how does one of those "electrostatic" filter panels work in your HVAC system. That is, the material attacts dirt.
But remember, this type of air filter runs essentially the same air over and over again until it filters out a specified level of particulate matter. So, if it misses the first time it gets it the next. Thus, it doesn't have to do it on the first take, as it were.
Oiled filters move a lot of air, but what isn't caught the first go around ends up inside the engine. Thus, the claim is that while they move air very well, they let in more dirt.
I strongly suspect that if someone used an oiled element, and used it properly, it would provide narry a problem.
Bob W.
The air moving through the filter creates a static charge opposite the polarity of the charge on the dust particles. The opposite charges draw the dust particles to the filter.quote:
Originally posted by Gary Allan:
but how does one of those "electrostatic" filter panels work in your HVAC system. That is, the material attacts dirt.
Some air handling filters use a power supply to enhance the effects. Some use a bigger power supply and don't need an element at all.
Dirt being attracted to an oil element because of molecular attraction sounds bogus.
Interesting observation, and a valid one IMHO.
Another one is that, to my knowledge, every off-road motorcycle, whether a desert sled, motocrosser or cow trailer, currently uses an oiled foam air cleaner in lieu of a paper one.
Bob W.
Lets not forget "thiggy" was asking us to compare oil bath filters to paper.
Isn't there is a difference between oil bath filters and oil coated foam/cotton filters?
Isn't there is a difference between oil bath filters and oil coated foam/cotton filters?
The old oil bath air cleaner (NOT filter) had an oil reservoir below a steel mesh section (kind'a like a Curly-Kate pot scrubber). The intake air bubbled throught the oil then up into the steel mesh section to scrub off the oil. No, they didn't remove as much dirt as a modern filter of any type.
The oil bath air cleaner will be a superb pre-filter when Mt. St. Helens blows again.
Ken
The oil bath air cleaner will be a superb pre-filter when Mt. St. Helens blows again.
Ken
The old oil bath air cleaners would filter well at high air flow velocities (high engine speeds), but not very well at low air velocities (idle).
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