Air filter maintenance!

[Buzzard Wing]

Clean air to the carb is important. It is pretty easy to change the oil in the air filter and I recommend yanking the 'cannister' and flushing it too.

Apparently I missed the important step when I put the loader Cub in service, but at least it had oil in it. The one on the left was after a few years of occasional mowing.



Some pretty interesting swill in the bottom, I guess it proves the filter does it's job.



This is the 'new' Cub... That IS how much oil was in it.... unfiltered air is bad....

[kthomas]

Good reminder Larry. Thanks for posting...That's ugly!!!

KT

[Arizona Mike]

[ntrenn]

Thanks for the visuals.

I've looked for quite some time about the oil bath cleaner's efficiency and pressure drop rating. Very little information out there as most everything in the world is paper media now. I know the K-N boys claim lots of stuff (no offense intended) but just about every test I've seen shows a standard paper filter has higher filtration efficiency and nearly identical pressure drop. Anybody have any charts they can share? I've thought really serious about changing to a paper panel from the oil bath for the efficiency improvement alone.

[Buzzard Wing]

Never really read up on it, but I believe the filtration in an oil bath is a good way to go. I suspect the reason they are not around anymore is it's much cheaper to use a paper filter. And someone gets to sell a filter.

I put a Donaldson 'PowerCore' in my Ford diesel. Now that is a filter! I had a K&N in another truck and I doubt I would get another, not convinced by their marketing. The real answer would show in an oil analysis. I know the Donaldson PowerCore does a great job of filtering.

[ntrenn]

A LONG time ago, I worked at a little equipment manufacturer by the name of Caterpillar Tractor Co. I clipped this from an installation guide.....Cleaner air makes for longer engine life..


Oil-Bath Air Cleaners
Oil-bath air cleaners, while sometimes requiredto meet customer specifications, are not recommended by Caterpillar. At best their efficiency is 95% as compared to 99.5% for dry-type filters. Their relative ease of serviceand insensitivity to water are advantages easily outweighed by disadvantages, such as:•
Lower efficiency
• Low ambient temperatures, low oil level,high restriction @ low air flow (such as at low idle), and installed tilt angle may lessen efficiency further.
• Oil carry-over, which is the oil becoming airborne in the air intake system whether resulting from overfilling or increased air flow, can seriously affect turbocharger and engine life, and may actually become an engine fuel.

We used to have 30" water restriction monitors on the filters way back then - amazing how dirty a filter has to get to get to 30"...

[Boss Hog]

the oil bath system must work fairly well, I have tore down 60 year old tractors that the rings were still good. lots of dust in a tobacco field., I raced go karts for years the K&N filters did not last very long even with an extra sock on them [ dirt track ] I do not believe the average Cub owner would do the required maintenance and replacement with a paper filter.

[Eugene]

I suspect that the oil bath air filters fell out of favor for several reasons, primarily the difference in manufacturing and initial installation costs of the oil bath filter versus two sheet metal stampings for a paper type air filter.

Second would be the physical size of oil bath air filters and finding an underhood location for installation.

[Jim Becker]

I think initial cost and maintenance time are the main reasons you don't see many oil bath air cleaners any more. The typical operating environment for most engines has changed too. Improvements in paper filter material have made them more appealing too. I suspect much of that came after the fact.

Here are some things I think are valid observations, but I didn't go research it:
- Relative performance level for each depends on the size particles being filtered. Oil bath is less effective on the smallest particles but about as effective with large particles. An efficiency figure that doesn't address particle size is fairly meaningless. You also need to consider the need to filter out the smallest particles, some don't make any practical difference.
- Oil bath cleaners probably have more flow restriction than a CLEAN paper filter.
- Flow through an oil bath is less sensitive to being dirty than a paper filter. Large particles can plug a paper filter fairly quickly. A dirty paper filter can choke an engine to a stall.
- Precleaners have been used with both types to improve effectiveness or extend service intervals. The need depends on the filter type and the operating environment.

Filtering needs for modern cars and trucks are much different than years ago. Most cars stay on paved roads now, so they take in much less large particle dust than in years past. Modern engines are probably more sensitive to fine particles than older ones as well. Combine these factors and a paper filter becomes more appropriate. Precleaners have been used on cars that operate in exceptionally dusty environments. Here is an example of a factory installed oil bath precleaner that feeds the standard paper filter:
http://www.steinborn.org/jim/corvair/monza-110a.jpg
Most modern off-road equipment that uses a paper filter also includes a centrifugal precleaner (I say "most", but know of no exceptions.). This is to deal with the rapid plugging a paper element is prone to from larger particles.

[ntrenn]

so.... a little internet shopping and some cross referencing and the Donaldson C045001 is just about a perfect size for the cub. Rated about 50 CFM and the cub needs 30 or so.

With a 1.5" inlet it could go right on the current breather inlet with a little adapting....

It's also known as a Wix 46332 or a Napa 6332...

Anybody ever try one?