Driving on dirt roads

[Ed Hackenbruch]

I think i will put one on my jeep.....and my bus!

[JohnEd]

I looked at the OIL BATH filters on a 4106 or 4105, don't remember which.  The "filter" seemed to be "three" oil bath filters mounted in the roof of the engine bay.  Not something you could transplant by any stretch.  I know three things about the oil bath.....so far  Firstly farmers have told me that the things worked really well and stopped the finest of particles.  Secondly, they are a high maint item.  Thirdly, they are very dirty to service.  Being high maint seems to be contested and some say they go pretty much all summer without service so maybe it is the environment of operation.  The dirty part is contradicted by some that have told me that the "can" on the bottom is held on by a spring clamp that is a quick release and that they only poured the oil off, swabbed out the dust, and put the old oil back in with a smidge added for loss.  Engine drain oil I suppose.  To me this did not sound like a major headache and I wondered why the change to $100 paper filters that you can't service. The "experts" that i talked to told me that there was never anything wrong with the oil bath and that paper was inferior in some respects and that reduced labor hours for maint was the motivation AND the element filter was cheaper to manufacture.  I am not a purist or sunk in antiquity traditionalist BUT, as Clifford says "has worked for 50 years really well so why change?".

From what I have learned, the oil bath(ob) is designed to work with a given displacement engine.  A filter for a 6V94 will be smaller than one for a 8V92.  Too big and it might pass dirt and too small and it will be restrictive ar high RPM.   Soooooooo, what is a source for a OB filter?  Would a 6 cylinder 92 ci per cylin "2 stroke" have the same air  volume thru put as a 4 cycle of equal size.  I know the 2 cycle has twice the power cycles and should act like an engine of twice the CI displacemenbt but there issome factor where the 2 cycle only equals somthing like 70% (some such number) of its apparent volume displacement.   I guess thaqt is two questions..where and how to size it.

Am I completely wrong in this quest? Its OK to call me stupid if you can provide the definitive answers.  A dirt road wouldn't matter to an engine with an OB filter.   Banzii!!! that dirt road.  A filter minder ain't god for much with a OB filter, either.

Thanks for the info,

John

John

[Lin]

I once read a comparative study of filters.  I think the oil bath did generally well but was not that good at low air volumes like idle.

[JohnEd]

I have never read that but  I know that YOU ARE CORRECT.  The OB depends on the velocity of the air making the "corner" inside the filter to "fling" the dirt at the surface of the oil.  Centripetal force.  The filter is designed for a specific volume and if operated under that volume then will not work well.  I think that is why the OB has a screen inside that gets whetted with oil and works at low air volumes.  Run for extended periods at idle I think the OB would fail to protect the engine and not be the appropriate filter application.  I see truckers let their "big rig's" sit and idle for many hours at truck stops.   Especially in the winter.  We don't do that with 2 strokes.

I really thank you for calling that to attention with some authority.  I have pondered that as a "flaw" for years but never asked and never heard it mentioned.  For those farmers operating in sever dust conditions to be proponents of the OB they surely must have been clued in.  Maybe engines that came so equipped came with a caution on the subject?  I sure don't know. Heck, I am still looking for a sizing and source.  I guess you could look up the specs on a 8V92 air filter for the answer.

Thank you for that information, Lin.

John

[belfert]

Falls Filtration Inc still makes oil bath filters for industrial use.  I would bet that could make one for a bus if you really wanted one.

It looks like General Eastern also made oil Bath filters, but they don't seem to show up as a current product on their web site.

[gus]

Lin,

My 4104 won't go fast enough to smooth out a washboard!!

I think a lot of the dusty engine problem is caused by missing engine bottom pans. I plan to make new ones one at a time to see what will be the effect - starting with the left side. I think the radiator fan sucks up a lot of dirt so a cover should help.

The left side is a pain though because of the exhaust pipes.