The Stovebolt Site Forums The Shop Area Engine Shop Oil bath air filter Upgrade - photo links

Here's a few photos from my completed conversion of an oil bath air filter to a paper element (from a Kohler 4508302 filter from a tractor engine..., or a K&N E-4583 if you prefer)
http://s1366.photobucket.com/user/nhluvstruck/library/Oil%20Bath%20Filter%20Upgrade
I have written up a step-by-step on this for the Tech Tips (pending) if you want to give it a go, or have always wondered what these things look like inside!

Thanks NH, I'm not one for cutting up original parts, but
that's one of the least most destructive modifications
that we've seen here.
Some others really hacked up their oil bath filter housing.
The E-4583 filter is a bit pricey but I see that it can be
cleaned and reused, clean it 10 times and it's cost is
reduced to less than a McDonald's kiddie meal.
I just know someone is going to post the bit about that filter
being for an 18 hp, 42 cu.in. lawnmower engine, and that the
surface area is not adequate for a 216 or 235 cu.in. Chevy
engine. But.....I've run the smaller CarQuest 83373 filter in the
spark arrestor that I linked to on my 216 and it ran just
fine for many thousands of miles.
Denny Graham
Sandwich, IL

It is my understanding, or misunderstanding, that it is better to keep an oil bath filter on engines that still have the stock draft tube emission system. Reason being that paper filters will clog up more quickly. Is that not true?

Modified a 47 Ford flattie air filter for a friend. Says his gas mileage improved over oil filter. Also claims to run better through the gears. Just sayin.

Denny, I actually used the non-KN paper version I got for $10 from Lowe's! If more airflow is needed then the K&N may be worth it - I've used them for years on my sports cars and swear by them.

Victor, that may be true...but I converted my 216 to a PCV and sealed the valve cover vents.

Couple questions:

1) Is cutting the top off the oil bath element part of the finished product, or just something you did to mock up the filter size? I assume it gets clamped down on top of the paper element inside the lid.

2). (This is not a criticism, I think this has a lot of potential ). Air takes the path of least resistance, right? And my crude understanding of the function (without my oil bath in front of me) would have the air coming through that foam floor you made. Wouldn't most of the air get pulled through the foam INSIDE the paper element, thus bypassing it?

If so, the simple solution would be creating a solid bottom for the portion inside the element.

Cut the green foam away on the inside of the filter, then the least resistance should be through the filter, up and over the center portion, and down to the carb. Some thin rubber or card stock would direct the air through the filter if laid over the foam before the paper element is installed. But, even with all that, the foam will do a good job of filtering.

I have two of these cleaned and ready to convert. Just haven't had the time yet or found the right filter. I now have a starting place.

Joe

That's more or less what I was envisioning. Just needed some confirmation on my logic.

Paper filter is going to be kind of a glorified spacer if the air isn't forced through it.

Still a really cool concept. As Denny mentions...much less monkey business than other attempts I've seen.

The air filter type would have no impact on the down draft system. They are completely separate systems separated by the pistons.
Carl

L [quote=JW51]
I don't understand question 1. I cut the bottom off the element to pull the guts out, not the top. I tested the mockup In the top cover and the bowl. Yes , you clamp the two together with a foam spacer and the wing nut to hold it all together.
For question 2, there is no foam "floor", it is a "ceiling", the filter element sits in the bowl directly and seals as any std filter with a rubber rim would. The top of the filter squeezes the foam ring in the cover tightly to hold the filter in place. There is a small ring of uncompressed foam around the outside of the filter that actually acts as a filter itself, increasing airflow, but not enough to bypass the filter. Also, the uncompressed part of the foam inside the filter was left in place to better hold everything in place, and filters the air after the air filter. There is no path that allows any unfiltered air past the filter. I have also done a version with an air impermeable UPE foam that is built up layers but found this version works better and is simpler. One more thing, is I have also done an all-foam version which can be done but I haven't tested yet. I'll put a few more photos up next chance I get.

Disregard question 1. I had completely misinterpreted what I was looking at.

My undiagnosed dyslexia got me on question 2. But reverse the question. Could the uncompressed foam outside the paper filter allow a path of lesser resistance? Air up through the foam and then straight down the carb. Still filtered via the foam I guess. But could a piece of impermeable material be added on that outer ring to completely block that path?

Sure enough. I had already made one of those out of the UPE but left it off for clarity for now:

Picture.

I doubt it is needed but plan on further testing when the truck gets on the road and sucks some dirt so I can see the airflow pattern. Thanks for the challenge as this is how we all improve.

For several years I have switched back and forth between a pair of stock oil baths and a pair of K & N's depending on what I feel like looking at and always notice a significant difference in throttle response after swapping. Probably not so much on a stock engine though...

I'll bite...which is better and what engine are you running?

I thought it would be obvious that the K&N filters breathe much better than the oil bath

Oil baths

K&N's

Engine specs:

1955 235 w/.080" overbore, Fenton dual intake/w sae 2 Rochester B's, split stock exhaust manifold, 261 cam, Pertronix ign. w/flamethrower coil, and mild porting.

In my case the difference is very noticeable.

I won't doubt your experience.

But if you would have asked me cold which flowed better...would have been a coIn flip in my mind. The air has to change direction in the oil bath, but whatever the guts are inside the element seem pretty loose.

Nice looking engine, BTW.

How so?

Brad

Edit- OP nice mod & thanks for sharing

re. Curts engines/air cleaners.

With the smooth chrome accessories the oil baths definitely looks real good and correct.

Conversely,

With the aluminum finned Fenton valve cover, your custom made K&N air cleaner setup definitely looks real good and correct.

So, in either case nice setup(s)

re. oil bath AC. Had I got my dual Rochesters to work like I wanted I would have stayed oil bath (as my 49 216 still is), but I went with more modern carbs so I went with a paper element type. I do like the looks of the oil bath setup....

re. OP, nice mod, thanks for sharing.

Dave

Okay. We have this now as a Tech Tip. Thank you Marc.

The tip is referred back here for discussion, so feel free to carry on the discussion.

Peggy

Curt the look of the pair of oil bath looks killer on that engine. To me, it is the cherry on top of the banana split.
Very nicely done.
Steve

I know this is an older thread, but I just added a factory PCV system that I found at a swap meet that came with all parts; rocker cover, PCV tube and valve, air filter, etc. In reading through tech tips I saw a tip on replacing the oil bath element. Liked the idea, thought it was a lot of work. So, started measuring and doing research. I found an air filter at summit racing that is 8 inches in diameter and 3 inches tall. I removed the factory oil bath guts and inserted this element. My clearances for air flow, height and everything else are nearly identical to the oil bath insert and I get better air flow. The summit filter is Summit Racingâ„¢ Reusable Air Filter Elements SUM-G3007
Part Number: SUM-G3007
I would post before and after pictures but can't get that to work. The appearance doesn't change.

BCB,
Thanks for info. Many of us have gone through the process the hunt and peck for that filter that might fit. Good find and thanks for sharing.
Pictures -- You may need a few more posts before your status allows for that.

I just went thru this conversion,
See link

https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/1502503/hanks-custodian.html

Chuck