How Often to Fully Flush the Oil Bath Air Cleaner?

[Hippie]

Minor question:
It's time to service my oil bath air cleaner.
I did the full kerosene flush and re-oiled the mesh (upper) element maybe a year and two cleanings ago.
Think it's needing it again--or should I just clean out and refill the bottom bowl?
How often should a fella do the whole enchilada on these things?

[type2sam]

According to Bob Hoover's TULZ Part 7, you should do the bowl clean/refill at every oil change, and the full enchilada 1x per year or "as necessary". As necessary relates to the dustiness of your environment.

Here's the link:

http://groups.google.com/group/rec.auto ... 37f34e39f0

Sounds like yours is due.

[hambone]

I think 1x a year is too frequent for the kerosene flush, it doesn't get that crudded-up even driving a lot of dusty roads. But check yours to be sure.
Changing the oil once a year seems like a good plan.

[Hippie]

Hammy you may be right, but I get a lot of dust in some of my off-road perfidy.
I think I'll just go for it with the kerosene today. I always have about 15-20 gallons on-hand anyway for my garage heater.
Thanks for the link too, t2sam

[hambone]

Hey check all your engine seals. I replaced a lot of mine and also sealed the gaps with silicone, much less dust. Lots of weird seals like the fresh air tubes to tin, oil breather, etc.

[Oregon72]

Hey check all your engine seals. I replaced a lot of mine and also sealed the gaps with silicone, much less dust. Lots of weird seals like the fresh air tubes to tin, oil breather, etc.

That is a great point hammy -- I'm trying to fix a lot of these openings on my rebuild I've been doing - lots of missing rubber grommets here and there - luckily a few of them can be sourced from the local hardware store if you know the size you're looking to get. There's always Traftons.

[Hippie]

Ya. Mine seal is pretty ragged...

[Hippie]

According to Bob Hoover's TULZ Part 7...

Thanks again for the link, that was a good read.

I only disagree with him on one point. He has always stated that the OB cleaner is better than "paper" and he offers no evidence of that.
(Rant done)

[Amskeptic]

According to Bob Hoover's TULZ Part 7...

Thanks again for the link, that was a good read.

I only disagree with him on one point. He has always stated that the OB cleaner is better than "paper" and he offers no evidence of that.
(Rant done)

OB is better. Oil has no micron limit.
Colin

[Hippie]

According to Bob Hoover's TULZ Part 7...

Thanks again for the link, that was a good read.

I only disagree with him on one point. He has always stated that the OB cleaner is better than "paper" and he offers no evidence of that.
(Rant done)

OB is better. Oil has no micron limit.
Colin

With all respect, Colin, if it caught all that went by the oil pool/oily mesh, that would be true. But it doesn't. 96% SAE efficiency is the very best you can expect.

With modern resin treated labyrinthine microfiber, I'll keep the 99.98% SAE J726 rated Hastings (or equivalent) "dry" element on my truck, thank you very much.

That's all I'm gonna say. Like I told Todd when we were discussing this, I don't argue it anymore. I don't care what people use. I've done my homework, and technology has indeed surpassed what we used to know of as a "paper" filter for a quite number of years now.

Rob

[Amskeptic]

With all respect, Colin, if it caught all that went by the oil pool/oily mesh, that would be true. But it doesn't. 96% SAE efficiency is the very best you can expect.

With modern resin treated labyrinthine microfiber, I'll keep the 99.98% SAE J726 rated Hastings (or equivalent) "dry" element on my truck, thank you very much.

That's all I'm gonna say.

Keep talking. Saying "that's it!" is a conversation killer and it suggests "attitude". I am here to learn. How about you?

My biggest problem with the typical paper filters is the typical plastic box that surrounds them. I have had issues with the plastic warping and not sealing half so well regardless of the advances in optimal paper filter testing. But, in the realm of the paper filters available for us "hobbyists". . . seen any Purolator paper filters for buses recently? They have decided to reduce the depth of the pleat by 50%. Seen the chinese crap at AutoZone recently? Doesn't quite reach the grooves in the plastic box. How about the delamination of the paper with the foam which is getting smaller and cheaper for us who own cars that do not have manufacturer support as far as correct dimensions and performance?

I am not about to get in a pissing match about optimal modern air filter performance in your truck. I just find that the cheesy paper filters with shoddy chrome caps and clips and the washable K&N filters, when used used on VW engines that came from the factory with oil bath filters, are a huge step backwards and I will continue to note my observations . . . in the severest terms possible.
Colin

[Hippie]

Keep talking. Saying "that's it!" is a conversation killer and it suggests "attitude". I am here to learn. How about you?...

I got tired of non-evidential crap on the Samba and other places regarding air filtration.
What I know about it is in my previous post. I will add that both filters rely not just on a micronically small particle becoming jammed into a hole that is too small for it to pass, but on the centripetal force accociated with being requied to change directions repeatedly. The difference on the paper air filter is that a captured particla can either be wedged into a hole or a vee between fibers, or become stuck on a resin coated fiber's surface.
In that sense, both oil bath oil filters and dry elempent filters work the same way. OB uses wet oil as a tackifier and prefilter, dry element uses resin as a tackifier, and usually (or at least often) an integral prefilter in the fact that the fibers are laid out in a dual density overlay.
The dry elements lack the pool of oil prefilter, of course, but have much finer porosity.
The oil baths rely almost exclusively on the centripetal force to throw particulates into the oil and then follow this with a repeated change of direction (again cent. force) to stick the particles to the depth mesh.
The oil mesh is very course, and in spite of its depth (more chances for a terminal particle contact) the finer engine damaging size particals in the 5 to 10 micron range tend to stay in the air flow without making contact.
The net result for a practical OB air filter is a lower efficiency, especially in the fine partical range.
Having said that, all filters of a type are not created equal.
It is obviously perfectly possible to build an OB filter that exceeds the performance of a typical dry filter, jut as it is possible to put a dry HEPA filter on your engine to keep out even bacteria. In terms of practical availablity, cost, and space, however, you will not be wanting to retrofit your Lexus for an OB filter--even a nice Knecht-VW.

I am not about to get in a pissing match about optimal modern air filter performance in your truck. I just find that the cheesy paper filters with shoddy chrome caps and clips and the washable K&N filters, when used used on VW engines that came from the factory with oil bath filters, are a huge step backwards...

Who said anything about a pissing match?
I don't know anything about ACVWs aftermarkets--you got me there.
I was speaking in general terms as was Bob Hoover (and you, until now) who made blanket statements that an oil bath was/is better without qualifying the reasoning .

Your point is well taken though--as I would expect nothing better than aftermarket junk for these cars. K&N filters are not up to par with most paper types on efficiency. Typically about 97% That is well known. Just hold one up to the light and see all the pinholes. It looks like the Milky Way. For oiled cotton gauze aftermarkets, I would look into AFE or S&B. Either way, you'll never notice a difference in air-flow as the vast majority of pressure drop occurs across the intake piping and elbows rather than the filter element itself. You'll want at least 99% efficiency for best protection. Also, I wouldn't necessarily judge the Purolator by media thickness alone. You'd need a microscope. Media designs change all the time.

You drive a lot of miles in a lot of dusty conditions.
I suggest if you do want to make a rough field comparison, you to apply an opaque layer of flat white paint to an area well exposed to airflow in your airbox or inlet tube after the filter, before the engine. When that is thouroughly dry, a tinyest thin layer of Vasoline on the paint is optional.
Vasoline is a good indicator as it is light and transparent. Grease is not.
The paint layer adds visibility, of course, but also prevents any blackness from old rubber or plastic from giving a false visual when you wipe it for inspection with a Puffs Plus with lotion after several thousand miles.

Did I talk enough?

Hugs and Kisses,
Rob

[Hippie]

bump

[Amskeptic]

bump

Hi. How much difference do you find between testing environments and real life environments? Unlike oil filters, which let you know if you did not correctly install them, I would think that uncomfortable or inaccessible air filter locations, coupled with goobered clips etc, would have a severe effect on engine life. An oil bath air cleaner seems to be more likely to have to be assembled correctly.
Colin

[hambone]

Wasn't oil bath discontinued merely because of the shop-time needed to properly service them?
Knowing manufactured goods, it seems like most things constructed after the mid 70s are considered disposable. Those old oil baths are built like tanks to last many lifetimes. My '73 Super had the plastic housing for the paper filter. Shoddy really. Did the job though.
Now I'm no scientist and am not familiar with microscopic membranes. But I do want a filtration system as rugged as my bus to withstand not only demanding city driving but the rigors of unmaintained old mountain roads. I like stuff that's built like a brick. Shut the door with a hearty KLUNK yeah that's the stuff!
A properly maintained system in good order is really what's important. And to have good quality disposable parts..............can we count on the latter much anymore? Even Bosch points are folding up.
Funny, we have to visit other eras to understand quality.