The Stovebolt Site Forums The Shop Area Engine Shop Stovebolt Air Cleaner Closeout Deal

Rock Auto has a closeout deal on these air cleaners. If you have an air cleaner like mine in the photo, you probably paid $15 -$29 for a NAPA 2375 or another equivalent brand name.

This one is a Luber-Finer AF213 for $3.43. I bought five of them for a total of $25 with shipping.

It's 6 inches by 2 inches.

https://www.rockauto.com/en/partsearch/?mfr=LUBER-FINER&partnum=af213

For future reference, here are some cross reference numbers for the same size filter.

NAPA 2375
Hastings AF54
Baldwin PA678
Carquest 67375
Fram CA77
Fleetguard AF843
Luber-Finer AF213


Use this discount code for 5% off total. 259044398181075322

exp 3-22-24

I thought you had downloaded and posted a picture of my air cleaner. I am jumping on rock Auto right now. thanks for the heads up.

I just bought two, I figured for $9 shipping I might as well get a couple but still a great price.

Sorry I forgot to post this with the original post. Enter the code below for 5% off your total purchase. Unlimited use. Enter where it asks "How Did You Hear About Us?"

259044398181075322

exp 3-22-24

Oh, and mention you heard it here. We would like to see if they want to "sponsor" the site ... one of these days.

Just a comment;

The original filter element on this type of standard or “pancake” Air Cleaner consists of coarse steel shavings molded into a circle and enclosed by a steel sheetmetal wrapper with drilled holes. Cleaned by slushing in solvent, drying then dipped in fresh motor oil.

Pic is from signature 1955.1 3100.

Yes, that's right. My truck didn't have that part and I suspect many others have disappeared over the years so the same sized paper filter is conveniently substituted.

Ol 55, did you install that pcv system or is that a stock configuration? I've never seen a pcv valve that wasn't stuck directly in the valve cover.

Sounds good; a resourceful application.

Locally, those old Chevy 6 pancake air cleaners are popular with the Low Rider community and command premium prices when one can be found. I think they’ve sourced a shorter paper filter element to retain the “look” on custom cars, but I don’t where that source would be.

That PCV system is the boxed original / Genuine AC kit acquired from a California Chevy dealer in 1972 for this model truck. Kit included installation instructions, an AC PCV valve, hoses, sheet metal screws, brass fittings for intake manifold, a steel core plug to fill the hole in the right-side block left from removing the road draft tube, and fittings for attaching hoses to valve cover and air cleaner. Instructions included details for hammering and brazing shut the four valve cover vents (early ‘55 235), but I opted to close off the vents from inside to retain factory appearance. So, you’re looking at the GM designed smog kit for an old Stovebolt; ca. 1972.

In ‘72 I had just finished rebuilding the truck and CA DMV required smogging before the truck could be registered again. A Smog Test was required too, which the truck passed. Later, CA exempted all ‘74 and earlier models from emissions testing but the smog kit was left installed as-is. The truck still runs well in 2024; ~ 100K miles on engine now since its rebuild.

That's pretty neat. You should print up the instructions with pictures and pcv valve part number so other people can cobble one up. That looks a lot better than some of the ones with the pcv valve down at the draft tube or other designs of dubious functionality.

What confuses me about that system is that the hose on top the air cleaner seems like the carb would suck air from the valve cover rather than the other way around.

In other word it looks like crankcase air would be drawn from both hoses with no fresh replacement air.

Forgot to add the non-vented Filler Cap to the kit list; it replaced the orig vented cap.

Regrettably the printed kit instructions are long gone. I can do a photo shoot of the engine details, provide the PCV valve part number and add some written details.

The hose from air cleaner lid to rear of valve cover draws in filtered fresh air into the crankcase through air cleaner and valve cover. There is slight suction at the rear valve cover fitting when that hose is removed while engine is running.

Crankcase blowby is pulled from the front valve cover hose to intake manifold vacuum through the one way PCV valve, routing blowby into the engine’s cylinders to be burned. The road draft tube is removed and the orifice is plugged. In this closed PCV system, the crankcase operates under negative pressure.

Can’t argue with success. Trust the GM design?

I would like to know what the specs are of the filter element as far as airflow. The original filter did not restrict airflow like a small paper filter does. Add some road dirt to that paper filter and it gets a whole lot more restrictive to air flow.
I am sure that it would work just fine for most of us, given that many of us just use our trucks to transport lawn furniture and drink coolers back and forth to car show gatherings.

Carl, all I can tell you is I've been using a filter like this since 2021 for 5-6000 miles (and as far as I know that's the only type filter it has had for the previous 15 years). It does not restrict air flow in any way. The truck runs fine at all speeds with no bogging or over rich condition.

When placing the air cleaner on the carburetor of an idling engine, there is no rpm drop whatsoever.

I use this truck as an everyday hauler with loads of firewood and lots of other things. I've never experienced any problems that could be associated with poor fuel / air mixture. The only problems I've had were Chinese fuel pumps and contaminated gasoline from Sam's Club.

From Jim Carter; 1941 - Early 1955 Chevy:

Air Cleaner assembly: https://oldchevytrucks.com/me907.html

Air Cleaner element: https://oldchevytrucks.com/me238.html

Ol 55 ,

I definitely want to reproduce your PVC system. My California truck has those connections on the valve cover already but nothing was hooked up when i got it (it was blocked off). Your photo sure clears up that mystery. I've done the road tube modification but i like yours 10 times better.

What's the PVC #? Thanks!

The 80 cubic inch EVO engine on my Harley Davidson Soft Tail has a similar filter element, only it's almost twice as tall. If you stack three of those "closeout" filters on top of each other, they might flow enough air to avoid restricting the flow to a 235 engine. Running just one of them on a stovebolt will be the equivalent of driving with the choke closed about halfway.
Jerry

Otto,
Ordered a couple extra filters just now. Thanks for the heads up.

Craig

AC PCV valve part number: CV-609C

First photo shows original PCV valve that came with 1972 kit. Second photo shows replacement valve installed five years ago. (Original valve was still functioning as far as I could tell).

Think I’ll start a new thread in Engine Shop that covers PCV system installation on a 235 truck, with some photos.

ol 55, That's a fantastic idea and I see you have already posted your detailed installation with pictures in the ol 55 PCV Kit Installation... thread for all to see.

Thanks for doing that!

HRL, you know a lot more about these engines and pretty much any engine than I do. All I can say is that this style filter was on the truck when I got it and I average 11mpg-13mpg. The last tank was 11. sumpin' sumpin'. That seems about right to me. Are you saying that I would be seeing much greater fuel economy if I purchased one of the steel mesh filters? (I actually would have done that if I knew about them when I got the truck. I wasn't aware of a lot of things about it or what was even available until I found this site.)

Atlanta is basically at see sea level so maybe that helps since the air isn't thinned out.

How can the original 6" x 1" oil soaked , steel mesh filter allow more breathability than this 6" x 2" paper filter? While the engine is running with the filter removed, there is no change in rpm when the filter is installed. If the filter were choking the engine, wouldn't there be a noticeable change in rpm?

Here are the new filters. Ordered on Tuesday, received on Thursday. I hate shopping but shopping online is great!

Jerry,
Like Otto, I've been using similar paper air filter (Napa Gold 2373) for a couple three years now with no issues. Reading my truck's tach and with an additional shop tach attached, the RPM's are basically the same with or without the filter attached.

I hope these Rock Auto filters are anywhere near as good as my current Napa Gold.

Try it with a 4 gas exhaust analyzer or better yet, a water manometer plumbed to the air cleaner cover to measure the pressure drop across the filter element- - - -it's not RPM; it's the venturi vacuum in the carburetor that concerns me when using a too-small air filter element. Getting enough fuel isn't the problem- - -it's all about having a free flow of air to maintain the correct fuel/air mix for best efficiency, power output, and gas mileage.
Jerry

What kind of fuel mileage should a 1951 (replacement engine) 216 be expected to achieve if all variables are at optimum? If I've been running too rich all these years and miles and achieving 12 mpg, what could I expect if it wasn't running rich?

I'm also curious how a 6"x1" steel mesh filter can allow more fresh air into the engine than a 6" x 2" paper filter.

I removed the steel mesh element on my '56 Cadillac and replaced it with a paper filter (albeit it's about 15" by 4" which is the same size as the original steel mesh) and my fuel economy increased from 14mpg hwy to 16mpg hwy.

I put 30,000 miles on a '52 with a 216 and got 15 MPG whether the bed was empty or had a half a ton of fertilizer on a pallet in it, or driving it in town, or on a 1,000 mile trip on the interstate at 55 mph. I had the pancake filter with the oil-soaked mesh in it.
I currently drive a '50 with a '53 235 in it. Guess what, I get 15 MPG no matter what.
I also have a '49 that has a 350 and automatic transmission. 15 MPG.

That's funny.

Are your 216 and 235 engines rebuilt? Mine is "original". Who knows when the '51 engine was put in the truck and whether it was just pulled from a junkyard and installed or rebuilt first? Judging by the looks of the truck itself and its use on a farm for 40+ years I'd be inclined to think the engine was just pulled from a junker and dropped in.

What is your opinion of the reason for 11-13 mpg fuel economy? Age? Wear? Air cleaner type?

It would be interesting to monitor the pressure drop across various types and sizes of filter media- - - -metal mesh VS pleated paper, etc. About the only one I wouldn't waste my time testing would be the K&N that uses an oiled mesh media. One of them got so clogged on my Harley shortly after I bought it that the engine fuel-fouled spark plugs repeatedly. I switched to a 6" X 3" pleated paper filter, and almost doubleed the fuel mileage. I've been running the same set of spark plugs for three years. On the dirt track race engines, we would stack two 15" X 4" paper filters with a couple of layers of masking tape reinforcing the middle joint to be sure the 375 cubic inch (destroked 400) small block Chevy engine got enough air to turn 7K+ RPM.

It would be pretty simple to rig a water manometer to check on the pressure drop across various types and sizes of air filters, and "test- - - -not guess!"
Jerry

I have seen a plastic doodad that goes on a filter housing on a diesel engine which indicates when it is time to change the filter.
I have one laying around somewhere in my shop for some reason. Probably stole it from a place that fired me for no reason (or fired me for stealing small plastic doodads, i'm not sure)

I've seen those little air flow sensor things, too.

Otto, My 98 Suburban with 454 V8 has one of those filter indicators. I need a new one. It's labeled Donaldson who also make big truck air cleaners. Many KW and Peterbilt trucks I drove had dash gauges for both the air filter restriction and fuel filter restriction. The fuel one saved my bacon more than once, especially in winter. We carried a spare fuel filter in the tool box.

Where does one plumb the air filter monitor doo-dad?

I think one of those would have to be plumbed into a snorkel or other "closed" style air intake system.

Somewhere downstream of the air filter element.

I suppose you could cut a hole in the top center next to the fixing screw of an AF big enough for the rubber grommet. I'd be hesitant to do that on an original oil bath though. The thing about these monitors is that they record the peak restriction at full throttle and high RPM. Unless you live i a dusty area it's probably overkill. Just change the paper element at regular intervals or blow it out with an air hose when it's dirty. You should be able to see light through it when you're done. On an oil bath see how much dirt is in the bottom. They will hold a lot of dirt before the metal gauze needs washing. I do mine every spring and they're rarely dirty enough to bother but I do it anyway cause it costs about a pint of oil each. And it can be cheap oil too.

On diesel trucks it was usually in the pipe between the turbo intake and the external AF mounted on the side of the cab. Later, KW and Pete moved the AF under the hood and that raised the noise level in the cab. They included a note in the operator book saying not to worry about the "chuffing" sound at low RPM. Peak torque by then was down about 1100 RPM.
I'm thinking about a way to get the two air filters on my rig out from under the hood so it still looks good. Haven't come up with an idea yet. At full throttle they are noisy. The car ones had big silencers on them. If I found 2 car ones I'd install them. providing there's enough room between them.

There's a proper way to "blow out" a paper element air filter. Once you're through working it over with the air hose, soak the paper thoroughly with three ounces of gasoline. Not two ounces, not four- - - -exactly three ounces. Carefully place the gasoline soaked filter on a patch of bare dirt, light a match, and toss it at the filter from a safe distance. Then go buy a new filter element. The compressed air blows holes in the filter media approximetly big enough to throw a a bowling ball through it. You might as well not run a filter at all, as try to clean one with compressed air!
Jerry.

That's what my high school shop teacher said. Don't use compressed air. Just rap it like a tambourine to knock out any loose dirt, etc. Hold it up and look through it. If you can see light through it, re-use it. If not, replace it.

Fram used to supply shops with an "air filter tester"- - - -a round housing with a light bulb inside it. Place the used filter on the fixture, put the lid on, and push a button. The amount of light visible through the filter media would indicate if it needed replacing. Hint- - - -it had a VERY low-wattage bulb! Just a gimmick to help sell a lot of filters!
Jerry

Just like this

That's funny.

What bulb is specified?