Oil-Bath Air Filter Conversion?

[TerryS]

Originally Posted by LowTech

Question: What's the down side for the oil bath? There's gotta be one -- otherwise they'd still be using the technology on modern cars -- right?

Upside for a newer-style air filter?

Downside is really only it's size. When they were more commonly used, there wasn't the jungle of hoses and all the crap that goes along with modern, EPA regulated vehicles. Back then, most people did their own routine maintainance, and it was nothing to clean and change the oil once a year. Now, people generally don't do their own work, and take the car into the dealer for tuneups and rotine warranty checks, so it's easier to have their paper filters replaced at that time. Today, there just isn't any spare room underneath the hood, and housings for paper elements can be made from molded plastics to fit the contour of the space available. Provided it isn't overfilled, there's almost no chance of oil being drawn up, and into the carb, but any oil would simply wipe out the airflow meters used on efi vehicles.
Most large diesel farm machinery still uses the oil bath filter. Dust is a major problem when tractors are out busting sod, or harvesting grains. The oil in the bath traps all dust in the air, passing through the oil.
The upside of modern, smaller paper elements is pretty much the inverse of the above.

[LowTech]

Thanks Terry. Consider me fully repended and converted. WHAT WAS I THINKING!?

[pickuprover]

Terry, very well put. I like your style of debating.

[Greg S]

I seem to have a different experience with K&N than Terry does. I was as scepticale as anyone could be till I tried one. I wanted to adapt the Oil can into a filter element type but decided it was too much effort. The air would have to go down the outside of the filter and up through the center and somewhere in there cross the membrane. Too much like work I thought. I flatly didn't beleave K&N's claim of huge power increases. Till I tried it. I always compare new mods with performance between set points on local roads. There was no noticable increase in noise (like I thought there would be) and my road speed uphill and acceleration were both increased (2.25 petrol). The true test of filter ability is the tell tale smudge inside the tubing on the 'clean air' side of the filter. No smudge with the K&N. Most paper filters will show a smudge in my experience. The original oil bath also shows a smudge. My owners manual must be different than the ones you guys have because I'm sure mine says to change the oil monthly, daily if in extreme dusty areas. Mine got changed twice a year. K&N recommend cleaning once a year for a road vehicle and the $13 kit will do the filter many times. In use, the K&N will turn from a nice red colour to brown really fast, but still gives good air flow and still show light through it. I'm impressed because it seems to do just what K&N claims it will do. If you supplement any filter with a cyclone pre-cleaner and raised intake you will get even better preformance. I wonder about the ability of the oil bath when I look at the size of the spaces between the wire mesh. The dirt has to accidently strike an oil soaked wire to get trapped. There is an awful lot of space for that dirt to get by.

Biggest down side I know of for the Oil Bath filter is the huge amount of drag when trying to start a cold motor. In cold weather with thick oil, the starter motor has to drag air to bubble through the oil to start the engine. Once things are in motion, it no longer bubbles as oil is dragged up onto the wires and the air can make a clear passage from the intake and up through the element. It is only that first bubble or two that is difficult so your pistons are trying to draw a vacuum.

The one photo shows the K&N part number. It is the wrong opening diameter but a piece of exhaust pipe necked down fixes that. I installed it on the end of the original hose to make a quick return to O/B if I had to, and just incase the length of that hose is calculated into the performance figures for the motor. I don't want to loose low end torque.

Greg S

[onslow]

Originally Posted by TerryS

It may be low tech, Low Tech, but NOTHING filters better than your oil bath. All these conversions to webbers, leaving the empty air cleaner mount sitting there looks hokey. The freakin wire screen on the webber won't even keep out small children, and then people wonder why their rings are shot a few years later (But they briefly had more ((?)) power) Sometimes, you simply can't improve on the old ideas.

I totally agree with terry on this one the oil bath fitler is why an engine designed 50 years ago is capable of 350k and lasting extraordinary long periods often with poor servicing and extremely harsh enviroments the system works so why change it for the sake of change it does its job well its cheap to service,is modern always better I dont think so,people have problems with old landrovers are generally tinkerers who try to gain more fuel ecomomy,performance etc it generally costs them more in the long run when things fail or go bang ive seen many series motors in my time and without a shadow of a doubt the standard untouched motors are the best.
Cheers Onz

[theclay333]

I have a similar setup to greg s, except i (by complete luck) found a K&N filter designed for a motorcycle that has the same oval shape as the stock intake elbow. I have no complaints thus far, but i never ran the engine with the original filter, so i have nothing to compare to. If anyone is interested in the filter number i can get it and post a pic.

[braganjackson11]

yes please do post a pic and part number