Air Filter

[BLB27]

Should I put a air filter on the carb for my 1927 coupe?

[Norman Kling]

Some people use filters, however, you would need to lean the fuel mixture because it would be like driving with the choke pulled. The filter would help keep dust out of the engine, but since the engine is very low horsepower it would also limit the pulling of hills or speed on the road. But it is your car and your choice.
Norm

[Scott_Conger]

despite 15 million engines going over 90+ years without one, there are two very strong camps of opinion on your question

if I recall correctly that you sent your engine out for rebuild, your question should be directed to the rebuilder and follow his advice as he is the one who warrants its proper functioning for an agreed-upon period.

[TXGOAT2]

I use one on my car. I consider it a necessity because I have to operate on dusty dirt roads. Lang's and other vendors offer a foam type filter that installs with no permanent attachment. One drawback to most air cleaner installations is that they interfere with using the Ford hot intake air device. That's a minor issue here most of the time. I keep the filter clean, and my car performs well, easily exceeding 45 MPH under most conditions. Plugs stay clean and no fuel dilution is evident.

[Humblej]

Ford did not provide an air filter but he did provide a hot air pipe sometimes called a carb stove. A hot air pipe is essential during high humidity to prevent the carb from freezing up. No room for an air filter when using a hot air pipe.

[TXGOAT2]

The hot air pipe could be adapted to work with an air filter. I'd like to have a Donaldson-type air filter with a hot air arrangement that could be adjusted.

[Dennis Prince]

This has been discussed before and I have ask if the people who say that a filter will change the way your T runs have ever run a filter? So far I have never gotten an answer. I have run filters on all of my T and it doesn't change the way they run at all (as long as they are clean, just like any other motor)and I feel better knowing that my motor is not ingesting a bunch of dirt. My filters are designed to preheat the air as well.

IMG_5490.JPG (51.42 KiB) Viewed 4223 times

[Steve Jelf]

Rather than speculate about how many fairies can dance on the head of a pin, I decided to try a filter and see what it would do. I bought a generic filter at O'Reilly for about $20, stuck it on a piece of sink drain, and wired it to my NH. Why? Because I do a lot of driving on unpaved country roads. I also use engine pans for the same reason.

I haven't detected any choke-like effect. Sometimes I've seen sweat on the carb and intake, but so far no "freezing up". As Dude Lester said, "It don't hurt the runnin' of it none."

Since that initial installation six years ago, I've replaced the baling wire with some DIY mounting hardware.

I hope I haven't voided the Ford warranty.

[Scott_Conger]

Here's my answer: My '13 runs horribly with a filter and great without. It's fitted with an NH. I've never bothered to fit a filter on my other 3 T's and they've all managed to survive it.

[jiminbartow]

I would say No! I have had my 1926 Coupe for 53 years and have always sought ways to make it run better from experimenting with all types of timers to using a filter in the hope it would keep impurities out of the engine. For several years, I experimented with a very well made filter on my 1926 coupe. While it looked good and probably kept the engine cleaner, my T never ever ran as good with a filter as it did with the hot air pipe, so I went back to the hot air pipe with no ill effects. Apparently, it has something to do with preheated air entering the carburetor. Ford engineers always knew what was best for the T, so I have stopped trying to second guess them. Now my engine is the way it was when it left the factory. No filter and the original roller type timer and it now runs great!

Second photo is my engine with a filter. Last photo is my engine now, with the hot air pipe reinstalled. I will never use a filter again. Jim Patrick

[TRDxB2]

Thought I see if there was a way to calculate proper air filter size and came across this site https://www.onallcylinders.com/2013/11/ ... ze-engine/
Just using these values for a Model T engine in their calculations to see what might be suggested
Displacement 176.7 cu” Brake H.P. 22 at 1600 R.P.M.
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Two factors dictate the filter size (area of the element): the engine’s cubic inch displacement and RPM at maximum horsepower.
A = (C.I.D. x RPM) / 25,500
A=(176.7cu x 1600 RPM) /25,500 = 11.087
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With the effective filtering area established, the required element height (including the rubber sealing edges), where H equals height and D the estimated maximum element diameter that will fit in the engine bay. The .75 figure is to account for the element’s rubber sealing edges: Going to assume a 4" diameter. The H value will indicate
H = A / (D x 3.14) + .75
H = (11.087 / (4" x 3.14)) +.75 = 1.63 inches height for a 4" diameter filter see attached
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H = (11.087 / (2" x 3.14)) +.75 = 2.515 inches height for a 2" diameter filter
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The issue with carburetor freezing is a very valid one and should not be ignored.
Now these values do not take into account the porosity of the filter element.
These dimensions are close (minimum) to what suppliers are selling and what people are using. So if you use one, bigger is better and use the least restrictive element possible.

[CudaMan]

https://www.google.com/search?q=air+fil ... e&ie=UTF-8

[Scott_Conger]

Ask yourself: what happens when I flood my carb and how flammable is a fuel-soaked paper or foam element if my car backfires after flooding?

Look at every ad for a period "T" air cleaner...every one I've ever seen is mounted on an elbow and is well above any point where raw gas could collect. If I was EVER inclined to run an air cleaner, it would be a period "cyclone" type that was mounted vertically and above the carb's bowl...I sure would not put a Briggs and Stratton foam or paper element hanging off of it to collect the inevitable fuel overflow.

[Susanne]

Here's the question... Whats the draw of your carb VS the intake limitations of whatever your filter you intent on putting there// i see people putting Briggs and stratton air filters on a much larger motor than their lawn mower, yet somehow this is OK... Even a Holley G has a far greater CI intake than your tecumseh lawn mower... So if you decide to put an air filter on your car, because you should actually KNOW about air flow, make SURE your air filter matches the size of your motor... And a lawn motor motor does NOT a 2 liter model T motor make....

[Les Schubert]

The problem I see with most of the air cleaners pictured is they aren’t big enough. I will post pics of what I use. Quite available and doesn’t get in the way.

[Craig Leach]

More than once I have found air filters on model A's that have a small tube that goes from the air filter base to the top of the Carb. bowl
added. As I understand this is to equalize the pressure between the air intake & the float bowl. Looking at Carbs. that are designed to have
a air filter you will almost always find the bowl vent in the air horn of the Carb. I have not tried this but my over carbureted speedster
runs much better at higher elevations with out the air filter. I keep it in the tool box for dirt roads.
Craig.

[TXGOAT2]

An undersize or dirty air filter will negatively affect engine performance, especially in an installation that lacks a compensated bowl vent. An undersized and dirty filter will certainly affect performance. The smaller the filter, the more frequent attention it will require in any given operating environment.

A Model T engine will suffer accellerated wear and combustion chamber deposits the same as any other engine when ingesting dust and grit. I drive my T, and want my engine to last, so I take sensible precautions to keep airborne abrasives out of it. The argument concerning a lack of intake air heat is valid. There are ways to offset that problem.

I have run my T many thousands of miles with no significant inconvenience resulting from its lack of any intake air heat apparatus. I do most driving in mild to hot weather, with relative humidity varying from around 10% to near 100%,and temperatures varying from around 50 F to over 100F, at elevations from around 800 ft to around 1400 ft.

Good paper air filters do not catch fire or blow out under ordinary conditions, and can actually contain backfires. I have driven my car over10,000 miles with a vendor-supplied oiled foam air filter, with no issues related to the air filter.

A filter mounted above the carburetor will not become soaked with gasoline if a pinhole is provided in an appropriate location for any liquid accumulation to drain off.

Many filter installations on tractors, including N series Fords, have a small drain hole with an Oilite plug at the lowest point in the air pipe or in the carburetor air horn to allow any liquid gasoline accumulation to drain off.

[TXGOAT2]

If removing the air filter improves performance, it indicates a need for a larger filter, or a least a cleaner one. A pipe on the carburetor inlet can actually improve performance at certain higher engine speeds if it is the correct size and length.

[Les Schubert]

[Bryant]

I agree with the concept of the air cleaner. as long as common sense is applied. I would also choose a cyclone style like my favorite pictured here.

still allows heat from the manifold and is a really neat piece.
And I also think running without one if fine as long as common sense is applied.
Bryant

[NoelChico]

There have been dynamometers at 2 tours I have been on. I'd like to run my car on a dynamo both with and without a filter and see the difference. Since engine rebuilds are spendy, and I drive on occasional gravel roads, I run one. I haven't tried to see the effect on top speed, because after breaking a fairly new axle, I'm no longer comfortable driving a 100 year old car that fast.

[Jerry VanOoteghem]

Two of my T's have Carter WO downdraft carburetors. I use an air cleaner to prevent stuff from falling into the intake. They look like 1955 Corvette air cleaners. Maybe they are?

[Oldav8tor]

Does treating the filter with Marvel Mystery Oil help? Just kidding. I run a foam filter bought from Langs. After running a heat pipe without a filter for a couple of years I installed the filter. I now have a few thousand miles on the filter without any apparent degradation of performance. I live in Michigan so we do experience occasional high humidity. I've driven in temps ranging from 40° to 90+° I've seen moisture condense on the intake but it's never iced up.

I like to drive local back roads and it always bothered me that the engine was sucking unfiltered air. Even a lawnmower has an air filter, so why not a Model T? The quality fuel available today doesn't have to be warmed to insure good vaporization and we've learned a lot about how to make an engine last longer in the past century.

Like everything else Model T, to each his own.

[Dennis Prince]

The picture I posted earlier was my first design, I have since changed to a larger more durable design. I have had this on the car from below sea level to over 13,000ft elevation and on some of the dustiest roads you can imagine and it has never hampered my performance at all. As a retired auto mechanic I can't bring myself to run any engine without filtering the air.

[TXGOAT2]

MMO would probably work well on an oiled foam filter. I have a can of K&N filter oil, so I use that. One thing to watch for with any foam type filter is any sign the foam is deteriorating. I've seen them fall apart and get pulled into the intake. On my car, I put a copper mesh pot scrubber between the foam element and the flywheel housing in hopes of increasing the flow area. I also stuffed some of the same material in the gap between # 2 & 3 cylinder to prevent dirt and bugs getting into the throttle rod hole. It collects a little oil mist from the engine and collects some dirt, so I'm sure it's doing some good.

[jiminbartow]

Do you think you could have the best of both worlds (the hot air pipe and a filter?)? What about stretching a nylon mesh paint filter across the intake opening of the carb prior to installing the hot air pipe? The end of the hot air pipe would hold it on. I don’t know how hot the air from the hot air pipe gets, but there would be a possibility that, if it did get too hot, it could melt the nylon mesh. One option to nylon would be to get a piece of micro mesh screen like the copper screen inside the fuel valve and put it across the carb intake and held in place by the hot air pipe. Do you think this concept would work?

McMaster-Carr has sizes 2 x 2 to 100 x 100 copper mesh screen and every size in between. For instance 2 x 2 means the screen has 2 x 2 (or 4) square openings per square inch. Each opening is 1/2” x 1/2”. 100 x 100 (or 10,000) square openings per square inch. That translates to a .006” x .006” opening. Small enough to keep sand and most debris out of the engine. They also have steel and stainless steel meshes in various sizes. Just a thought that I may try one day. Jim Patrick

[jiminbartow]

Dennis. Well done! That Rube Goldberg looking hot air filter looks right at home on a Model T. You could probably market that. Jim Patrick

[TXGOAT2]

I don't think you could beat the commonly available paper filters for effectiveness and convenience. If you could find an oil bath unit from an old Wisconsin V-4 engine, that would probably do nicely for a stock T engine. The 8N Ford tractors have a nice air filter arrangement, but it's rather large. Some small industrial stationary engines have compact air filters that could be adapted.

[Tadpole]

No you shouldn’t use a filter because it’s bad for the motor! But yes, you should use a filter otherwise it’s bad for the motor!

[TXGOAT2]

Dirt is very bad for the engine.