Intake icing up

[burner31]

Here's one for you, my intake is freezing up, I'm running an air cleaner, and while the car is running the intake gets very cold with dew forming on the outside, and the car runs like crap, smoking, missing, gutless...when I take off the air cleaner the car runs much better and the intake returns to normal.
I've never had this problem before and the filter seems clean, less then 200 miles on it on City streets. I'm going to put a new filter in and see what happens, but until I get the filter in I'll be running without.
Has anyone experienced this issue before? And what were the factors involved.

[H. L. Chauvin]

On a jovial note, please, where did you buy the air cleaner?

Sounds like I could hook it up to a window fan and air-condition my house.

[Mitch//pa]

What kind of filter are u using. Paper?

[Synchro909]

I started a thread on this a few days ago because it was happening to me - no, to my car. To overcome it, I intend drawing at least some of the intake air from around the exhaust manifold. It's not a terribly uncommon phenomenon but like you say, the car runs like crap. I'm sure warm air will eliminate it.

[Chris in CT]

Hi Keith, Weird it is, and not too long ago we had a similar complaint from a friend in Australia who was having a like problem. I would love to see a picture of your air cleaner and the method in which it attaches to your carburetor. The only logical explanation for your problem is that you are getting some kind of "pre-venture" (the spell-check will not allow me to put an "i" after the r in ventur...) effect in the intake bore of your carb. This also accounts for the "choking" you are also experiencing with bad running and black smoke.
The fact that this disappears when you remove the air cleaner really proves the point. The problem actually may not be the air cleaner itself, but whatever you have used to hook the air cleaner to the carb. Also, some of us insist that a carb be "air balanced" before an air cleaner can be mounted on the intake bore of the carb. Air balancing means that the air pressure inside the carburetor bowl is equal to the air pressure at the carburetor intake bore. Send us some pix of your intake hook-up...

[Charles Coe]

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Don't know about the icing but the air cleaner is probably restricting the air so you are running way too rich causing smoke.

[burner31]

Got the air cleaner from Snyder's, it has a paper filter. Filter points downward.
Thinking about the issue...I did blow my exhaust gasket last week (back two cylinders) and all those fumes could have been sucked up into the filter, coating it in carbon, soot and the like, would like to get foam filter that I can clean and re-use.

[Mitch//pa]

... deep six that paper filter they get fuel saturated and clogged... its also a fire hazzard
they should be outlawed for an A

[burner31]

Have to agree with you Mitch, getting the wire screen filter, it's re-usable and it keeps the big things out of the carb and most important...it breathes.

[BILL WILLIAMSON]

Is it COLD in Shawnee, Oklahoma????
Bill W.

[burner31]

90's to over 100, high humidity.
Very weird, I have never encountered anything like this before, but then again this is my first Model A.
Going to go with Mitch on this one, going to throw the paper filter as far as I can, hope the dog don't go the ten feet to bring it back.

[Jacksonlll]

Model A's love nice cold air going into the carb.
Pitch the filter and clean the plugs and it should be just fine.

[J Witt]

I'm running the High-Boy filter (bought from Snyders) and it has been very satisfactory. It sticks up near the aft end of the exhaust manifold so is getting fairly warm air. We'll see about icing this fall maybe.

This filter uses a cleanable K&N type oiled cotton mesh element and is apparently very low restriction. I can't notice any mixture change with or without it.

When I was racing Formula Ford cars I would occasionally see icing in Dallas in the summer, but the heat riser passage was blocked to get a cooler mixture. Carb heat is mandatory in normally aspirated light airplanes, and was even a problem in the B-36 in the 1950's because the carbs were on the cool side of the rear-facing engines.

John

[Ron Lachniet]

I had the same problem two years ago and could not remember how I fixed it, so I asked my friend who has a much better memory than mine and he reminded me that the problem was that my intake was insulated from the exhaust. I took my exhaust and intake off and had them ground flat while mated and put it back together with a good gasket and it took care of the problem. It took about thee oil changes to clean up the carbon and not have black oil but that cured it. Your intake needs heat from your exhaust to properly atomize the gas.

[burner31]

Removing the paper air filter, that solved it for me, have gone to a metal mesh screen, and now the world is right.