Carb Icing - Ice coated Air Filter

I'm having trouble with large cakes of ice building up on my air filter and puddles of water in the air cleaner. The car is 100% stock but I don't seem to have any mechanisms for heating the the stock air cleaner (long necked closed thingy).

It's a 1967 Chevy Camaro, V8-327 (210hp), 2bbl carb, 2 speed automatic (PowerGlide), California Car with an A.I.R. Emissions Pump (not currently connected with a belt), factory Air Conditioning, and it's being driven in Michigan but this is the first year I've had trouble in the 4 winters I've owned it.

It happens at below freezing temperatures. I'll be driving down the highway and loose power on about half the cylinders or more. Last time I noticed it was the spark plugs closest to the carb (#3, #5) that were fouled while the outer ones (#1 & #7) were like new. And once a couple weeks ago the throttle was stuck open until I stopped the car and let it sit for a couple minutes. But he plugs remain fouled and I nurse it home on half the cylinders and have trouble going up slight hills on the highway.

The only connections to the air cleaner are: One hose that comes I believe from the crankcase, it has a flame arrestor on top of it. And another one hose from the A.I.R. Emissions Pump. There is no large hose (or connections for it) to draw heat from the exhaust manifold. (I know what this would look like on cars of the 70's).

I'm looking for ideas. I already changed the 180 thermostat to 195.

The A.I.R. pump does connect to the exhaust manifold but just through

4 brake line size tubes. This wouldn't be meant as a source of heat for the air cleaner would it? I'd have to replace the A.I.R. pump to find out because it's locked up solid and won't turn.

I did remove the clutch fan in recent years and installed a fixed fan (but with blades that bend to reduce air flow at high rpms) if this could be the problem. I've been looking for my clutch fan in jopes it would help. Or I may order a new one. I'm thinking a 2 speed transmission at 65mph with a fixed fan, probably blows a lot of cold air past the carb.

I also bought a new 2bbl carburator over the summer from one of the large Classic Camaro part catalogs. But it looked identical in every way.

Any other ideas? I can't try inverting the air cleaner cover because of the flame arrestor sticking up in the way. I haven't tried one person's idea of putting a piece of cardboard in front of the radiator yet, because I'm afraid it will make a mess when it gets wet.

Would an aftermarket "open" air cleaner help? (Filter sandwhiched between two chrome plates). My local auto part store says it would probably make it worse.

I never had this trouble when I had my 66 Impala, and it had pretty much the same setup with a 2 speed trans, 2bbl carb, factory air cleaner, fixed fan blades, etc.

This is my only car and I need it for work if anyone can help! Thanks!

Reply to
Richard
Loading thread data ...

One additional note. I just found the oil level was a little over full by about 1/3 of a quart (so it could have been 1/2 quart over when this started). I drained it. I'm hoping that contributed to the spark plug fouling. I checked it cold (about 15 degrees F in the garage). Don't know if I should be checking it warm instead.

But the carb icing (more accurately the air filter icing), remains a mystery.

Reply to
Richard

Being a California car it wouldn't have the heat stove. Nor would it have hood insulation. You car was not meant for cold weather (below 30) operation. I would hazard a guess what is happening as the air is sucked thru the small opening on the air cleaner snot, it is cooling it off till the point that ice starts to form.

Just to see if this could be the cause, you can try the inbred fix for it. Flip the air cleaner lid upside down and try driving the distance this happens at. If that alone take care of it, an open element air cleaner would be the cheap fix.

If not I would try some aftermarket hood insulation. The stuff with the reflective foil.

Charles

Reply to
Charles Bendig

I would be tempted to se if you can find a air filter assembly that has the heat tube that draws air of the exhaust manifold. Hit the wrecking yards. You may not get one specific to you car, but as long as it fits the carb, and fits under the hood you should be able to cobble it togather. You could install it for winter use and return to stock in the summer. Greg

Reply to
Greg O

Your problem may be that the exhaust heat crossover under the carburetor has been blocked off, or has been plugged up with excessive carbon. Unfortunately I know of no way to confirm this without removing the intake manifold.

Reply to
Gary - KQ6RT

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.