carb icing, what to do?

[a2tripp]

a common problem where I live is moisture and carb icing. Since I drive my truck daily, is there something out there for us? I bought the truck down south and it came with an open element filter and carter afb, even if I got a stock like assembly (thinkin 90's chevy) for the choke heater/ stove pipe or whatever they are called there are no provisions on the ramhorn manifold. What does everyone up north do for this?

[fastwillie 696969]

drink vodka ?

[domeier]

If you have a heat riser, you could maybe make a manual control for it with a vacuum switch?

[yuccales]

Maybe a plate like this in front of the carb might keep the air from your fan adding to your iceing problem? Also a "winter front" for the radiator may help.

[donut]

I used to have an old Impala that used to ice up. Blocking part of the rad helped, if it doesn't run hot.
My plow truck used to have the air filter freeze up on me, (snow, slush re-freezing) that was solved with an OEM aircleaner setup when the weather started cooling down.

[71tahoe]

I had a carb freeze on a cool, foggy morning here in Arkansas. Wound up being a stuck PCV. Too much fuel pulled through the carb. Fouled the plugs too. A tune up might help too.

[MacGyver72]

You may think this is insane and I don't know if it'll work or not because I don't know the areas of the carb you're having problems with but here goes. You need a dessicant to rid your carb of moisture caused by moist air settling in and on your carb when it is runnning and warm then freezing. try putting rice in your air filter or around it if you have the stock air cleaner. Rice is a super dessicant and will rid your carb of moisture.

[geezer#99]

1. Get a winter front for your grill.
2. Use a newer air cleaner with the hot air stove hook up. Find one with a large air intake snout. Close off the flapper in the snout so all the hot air is drawn in from the exhaust manifold. Look around a wrecking yard for an exhaust manifold with a large heat stove attached. Use it to make one to fit your ram's horns. I've seen large heat stoves on BBC and BBF.

[slomotion]

No disrespect intended here, but I doubt rice will help. The air moving through the aircleaner is moving so fast, the rice wouldn't have time to pick up anything. Worst case, the rice would be ingested by the engine...not good.
The pressure drop of the air through the venturi is what causes the moisture to freeze in the carb. I'm guessing the problem is worse when the ambient temps are in the middle 30's to low 40's. The manufacturers put a heated intake manifold on the early engines that had exhaust heat diverted to them through the exhaust manifold. If you have a stock exhaust manifold make sure the "heat riser valve" on the exhaust manifold is free to move. (It should be on the passenger side, under the manifold.) It has a weight on one side, and a coiled spring looking piece on the other side which heats up, and slowly opens to allow the exhaust to pass un-obstructed once the engine warms up. I don't know how much your set up has been modified, but your end goal will be to keep the carb warm (or the air going into the carb) until the engine completely heats up. At that point "heat soak" will keep the moisture from freezing.

[MacGyver72]

No offense taken Slomotion. As you point out, it must be outside the air cleaner and not in a large enough quantity to clog the air filter which is why it needs to be the stock type of air cleaner so the rice can be placed around the filter. It will be most effective at rest when the engine is cooling down. There is no need to remove moisture when the engine is running. It's the potential freezing of suspended moisture that is the issue. And this is by no means the preferred mod. I don't know enough about his engine specifics or his budget but I'm confident that a dollar's worth of rice will eliminate his headache until the proper engine mods can be made.

[ChevLoRay]

Originally Posted by MacGyver72

You may think this is insane and I don't know if it'll work or not because I don't know the areas of the carb you're having problems with but here goes. You need a dessicant to rid your carb of moisture caused by moist air settling in and on your carb when it is runnning and warm then freezing. try putting rice in your air filter or around it if you have the stock air cleaner. Rice is a super dessicant and will rid your carb of moisture.

The military (USAF) used screw-in dessicant devices in the wave-guide of the radar systems I worked on.

When I was at ALCOA, we made the material that was used as a dessicant, from hydrated alumina that was refined into a material we called Hydral. From there, it was made into a gel, and then formed into balls from 1/8th inch to 1/4-inch in diameter. After the drying process, it was a finished product. It was the smaller size that went into the holder that was installed in the waveguide. The material was coated so it would change color when it was time to change it, but ultimately, all you had to do was heat it in an oven and dry it out and it was good to go again.

Rice does an excellent job of keeping moisture from letting the salt shakers get clumped-up. My great-grandfather used rice to absorb the water from his shoes, when he worked in the rice fields, as a blacksmith. He decided to dry the soaked rice one day, and it became puffed rice. That ultimately led to the development of crisped rice, after some cereal folks kept working on it.

[domeier]

The reason a dessicant wouldn't work here is because of constant exposure to moisture, and the large volume of air that's being drawn in. Carb icing is a constant threat to carbureted aircraft, so they're built with a system to draw alternate intake air from a heat muff on the exhaust. It decreases power by about 10% when activated, so is only used when needed.

Also, since aircraft carbs are updraft, mounted under the engine, they don't pick up any heatsoak from the engine.

[1972RedNeck]

We have that problem quite often in Montana too. Just open up the 4 barrels on the road until the motor gets warm.

[a2tripp]

The problem is the worst when the temps are in the 40's and during morning warmup. You can take a blow dryer and blow it in the intake and it will clear up instantly.
This is very annoying because you have to feather the throttle until the motor completely warms or it will die in gear or on the brakes. This requires 10-15 minutes time/ gas to deal with it. Others here have the same problem and they deal with it or have some type of provision in the intake or exhaust manifolds. I have nothing on my manifolds, so fabricating something will be my last resort. To battle this on other motors (360amc and 360dodge)I used a suggestion from a friend to use a cut up coffee can and aluminum foil. This works ok, but creates rattles, and will rust out every year. Actual ice will not build up unless I am farther up north at highway speeds. blocking the radiator with cardboard works great in that situation.
Moisture on the element also contributes, but the problem is still there with a new filter.
silicia (sp) from shoe boxes, those little packages are no help.
If there was a heat valve after the manifold its long gone now, in the past though these have not helped.
I like the idea of a plate blocking the fan, I thought about taking the fan off and seeing how it does but the po super riveted the shroud on.
I live in what seems the rainiest part of the world, it rains over 13ft/ year and we have not had a sunny day in over 2 months.
I really appreciate the suggestions, other than ditching the carter carb and going to a holley or efi i might be sol. I have to believe that someone sales a solution to this, in a box that can be delivered, looks half way decent, and be corrosion resistant.
Thanks again and sorry about the long post. I drive my truck as much as possible and am proud of how well she runs, but warming up in the morning wakes the kid and wife, not to mention my rotton neighbors.

[a2tripp]

Originally Posted by domeier

Carb icing is a constant threat to carbureted aircraft, so they're built with a system to draw alternate intake air from a heat muff on the exhaust. It decreases power by about 10% when activated, so is only used when needed.

I too work in the avation industry, been brainstorming and thinking a electronic exhaust cutout that those racing car guys use, piping that into the intake.

[pumpkin]

The best fix is the stock set up. Heat stove pipe from exhaust manifold to stock air cleaner, heat riser valve or efe valve. Make sure the exhaust crossover in the intake manifold is not plugged. its kinda cool to watch when you look down the carb and see the ice forming on the throttle plates.

[STOCKISH]

Swap to fuel injection? Holley makes a bolt on t.b. system that works great and will fix the fuel issue for sure.

[a2tripp]

Originally Posted by 1972SuperCheyenne

Swap to fuel injection? Holley makes a bolt on t.b. system that works great and will fix the fuel issue for sure.

we use holley pro injection on three different ground services vehicles at work, they are just as much as a hassle.

I am going to look for a tac air cleaner today and go from there, thanks everyone!

[bigsnookmaster]

Just move on down here to Florida! Icing problem fixed!!!.......Good luck.

[STOCKISH]

Originally Posted by a2tripp

we use holley pro injection on three different ground services vehicles at work, they are just as much as a hassle.

I am going to look for a tac air cleaner today and go from there, thanks everyone!

No joke? WOW, I guess the temps there are just really hard to work against. Hopefully the heat riser will help a bit. Good luck.

[RUSHNBOBO]

this will work.......(once)

[a2tripp]

Originally Posted by 1972SuperCheyenne

No joke? WOW, I guess the temps there are just really hard to work against. Hopefully the heat riser will help a bit. Good luck.

The holley tbi we use cuts off the fast idle solenoid at 75 degrees, these are in tugs that move float planes on trailers around, mostly they just idle, and theres no adjustment.
Its really not the temps, actually the issue is better in sub zero temps, its the 40's we got now that its the worst

[dagoat]

Another thought to ponder. My thirdgen firebird uses coolant running beside the throttle body in order to prevent icing. I don't know of any vehicle carbs off hand that allow coolant to flow through, but I do know there are carbs for motorcycles that have passages for coolant.

[domeier]

Originally Posted by dagoat

Another thought to ponder. My thirdgen firebird uses coolant running beside the throttle body in order to prevent icing. I don't know of any vehicle carbs off hand that allow coolant to flow through, but I do know there are carbs for motorcycles that have passages for coolant.

When I bought my truck it had a water jacketed spacer between the Holley 600 and manifold. I guess it was to heat the carb? I guess? I guess I don't know what it was supposed to do. I threw it away.

[a2tripp]

I think the older carbed s10 had a electric setup like that. Looking on the web I havent found anything aftermarket though