Air filter too old?

[crvc]

I have a 1967 bug with a newish 1640cc DP stock engine. With the original oil bath air filter. I noticed with the engine idling when I lifted the oil bath off the carb there was a "whoosh" of sound as if I'd removed an obstruction to the air flow. Could the big filter top collect enough debris after 50 years and need to be replaced? Is it possible to find another top?

TIA,

kevin

[SCOTTRODS]

I've had success cleaning one in the past, by soaking in Diesel or kerosene for a while and then rinsing it out with fresh Solvent as well... Sloshing it around once in a while helps shake loose debris as well. Doesn't mean it's the vest way, but I've done it on filters that were exposed to high dust areas.

[Marc]

Could be a big factor in the lousy fuel economy you've reported as well...

[helowrench]

I had a terrible time trying to fully clean out the one on my Ghia
125K mi total at the time, with 75K mi in W texas battling sand and dust.
tried all of the tricks, including being submerged in a cleaning tank for days, followed by backflushing with solvent for 16hrs.
Finally gave up, and used the round 6" on the end of the ghia/bus elbow (to control the fuel standoff) mileage went up, and also above 4000 rpm operation had way more power.

So, I came to the conclusion that these are indeed a Time Life Limited item.

[Piledriver]

I think you can still get the late Mexico paper element style units, do they fit the early carbs?
(I want to say yes, but I haven't had a 28 PICT in my hands for 30 years)

Those are better filters anyway.

[Marc]

The US-market paper-element filters used in `73/`74 will fit any Solex Beetle carb - everything from 28PCI thru 34PICT-4 has the same airhorn diameter. However they use a larger-diameter crankcase ventilation hose so that must be adapted - or the breather/filler can be replaced, but that eliminates the roaddraft tube (those cans are infamous for rusting out form collected moisture). Their temperature-control flap is vacuum-actuated so for it to function you'd need a source of manifold vacuum.

[crvc]

How can I tell whether the oil bath is clogged? Reading Rob & Dave I see how important the stock oil bath cleaner is. I assume the filter material is some sort of steel wool? If so how could I replace the medium?

TIA,

kevin

[Marc]

Never tried cutting one open to change the filter media but don't see why it couldn't be done - sealing it back up when you're finished would be the challenge. A lot of farm tractors use oil-bath aircleaners which are designed for replaceability, you should be able to pick up something at a shop that works on them.
Question: at what level do you run the oil? There's a red line and/or an embossed arrowhead which indicates the proper level.

[crvc]

Never tried cutting one open to change the filter media but don't see why it couldn't be done - sealing it back up when you're finished would be the challenge. A lot of farm tractors use oil-bath aircleaners which are designed for replaceability, you should be able to pick up something at a shop that works on them.
Question: at what level do you run the oil? There's a red line and/or an embossed arrowhead which indicates the proper level.

I fill to the red line.

kevin

[helowrench]

when I was dealing with mine, I noticed that it was filled with a natural type of fiber, similar to the material inside the seats.
coconut fiber, sisal,?

[Piledriver]

I always thought it was rubberized horse hair.
(like the original seat padding)

The only references I can find refer to it as "hair material".

Aussiebugs functional description on TOS does register that the rather softly packed hair was simply an air-oil separator, most filtration was done by the 90 degree turn at the oil surface and simple intertia.

This makes me wonder if its simply the airflow redirection at oil level rather than any filtering action of the upper section causing the perceived restriction.

A sensitive ~water column scale manometer could remove all doubt if there was a real restriction...
First with no oil (extra turning radii)
The post test would be with no fiber filler.

[Marc]

That's what it looks like peering through the holes in the bottom...apparently something that has proven to not be dangerously flammable when soaked with oil and exposed to backfire flame
I've heard of folks using Scotchbrite pads as oil-bath media, but that seems a little risky to me. I'd sooner stuff in handfulls of swarf swept from the floor around a local machine-shop's lathe or some super-coarse steel wool...the majority of the incoming dust is deposited in the oil when it can't change directions as fast as the air does; a small amount of oil wafts up onto the media, making it sticky enough to entrap most of the lighter particles. In principle, there really shouldn't ever be a need to replace it - soaking/flushing should make it good as new - at least if you don't make a habit of driving through clouds of fiberglass or asbestos dust. I suppose organic stuff like cottonwood fluff could also end up hopelessly entrapped, too.

[Piledriver]

Oh god no not scotchbrite pads, they start breaking down and releasing aluminum oxide abrasive just soaking in rubbing alcohol...
Might as well pour sand down the intake.
You'd be better off most places with K&Ns, not that they actually stop much, at least they don't shed abrasives.

The woven steel wool pads might provide too much restriction for an air cleaner due to cross section of the material and the density of the loops.
The "woven" or curly steel wool pads seem to hold up in my case breather fine, seems to be one continuous strand of material.
(yes, I tried picking one apart to see if there were any loose bits. Waste of time)

Some combine both designs, a bunch of curly stuff in a sewn up bag of woven SS threads.
Don't use copper scrub pads---it can corrode.

[crvc]

http://i1325.photobucket.com/albums/u63 ... 34be00.jpg

I wanted to get hot air from the left side cylinders. At first I welded an inch wide metal tube on the back of the oil bath but the engine lid collapsed the air tube. So I jerry-rigged a plumbing spout.

kevin

[Marc]

hmmmphh....how's about putting the right aircleaner on there and killing two birds with one stone?
What breastplate/warmair pickup pipe arrangement do you have? If it supports two small hoses, it's `67 only. If only one on the left, a `65/`66 aircleaner would be correct (you could still use a `67, of course). Either of these is designed to admit warm air only at idle, regardless of ambient temperature.
Where you live it's cold enough that a properly-functioning thermostatic aircleaner is pretty important. Best setup IMO is the c1971 with self-contained wax-pill t'stat and a large hose on the right side; that'd require changing to a `68-`71 or `72-`74 breastplate, rear tin, and pickup tube. That arrangement will support any `68-`74 aircleaner, but the cables for the mechanically-actuated ones are rare as hen's teeth and the vacuum-actuated ones are often problematic, so the self-contained type's worth hunting down.