philoldsmobile

I have fitted the Edlebrock open element air filter to my car. I have felt a small but definate power increace, but i am concerned about carb icing.

Has anyone with this type of air filter had problems with icing in winter? If so how cold does it need to be before it ices. Should i put the stock air cleaner back on for winter?

Typical winter temp here is about -4c during the night and about 3 - 5 c during the day, it rarely gets any worse than that.

eric17422001

Yes, you are indeed ill. Once you have worked on a Maeserati Biturbo you will understand. Although better than a Peugeot from what I understand.

Eric

Kevin Johnson

A good compromise might be to use the stock air-cleaner housing with a taller 3 1/2" element. The lid you'll need is quite common and cheap and even if you couldn't find it in England, it shouldn't cost very much to send one over from the States.

That was my first mod and I noticed a power increase. There are articles and posts on how to make your own dual-snorkel set-up. Below is some info on carb icing. Seems like the English climate might be prone to this. Your best bet is to enquire at a local speed shop or on-line old car club. Anybody with an older car fitted with sidedrafts will probably be familiar with the risks there.


http://www.flyafi.com/tales/tales.htm

CARBURETOR ICE 101
For carb ice to form, conditions must include muggy air and carb temperatures at or below freezing. Carbureted engines (those without fuel injection) mix fuel and air in a carburetor venturi. The venturi is a narrow passageway in the induction system that accelerates airflow and draws fuel into the manifold. As the air accelerates, its temperature drops -- sometimes as much as 40 degrees or more Fahrenheit! Result: If the air coming into the engine is moist and the temperature inside the carburetor is at or below freezing, ice can form. The ice blocks airflow to the engine and, without air, combustion stops and the engine fails.

You should always suspect carb ice when:

Relative Humidity is greater than 70%,
Temperature/Dewpoint spread is less than five degrees Fahrenheit, and
Outside Air Temperature is less than 70 degrees Fahrenheit.

philoldsmobile

mmm, i'm getting mixed messages from a lot of people, I might just replace the stock air cleaner and leave it on until after Easter.

kid camaro

iTrader: (1)

when i lived in canada i had a k&n open elemnt filter and i never changed it when winter hit and i never had any probs with it. it actually made my car feel faster. the temps where i lived would get to about -35' celcius. id say ya should be ok to leave it on.

Apeiron

Carburetor icing is a problem for aircraft, not for cars. I doubt you'll ever encounter conditions where it would occur.

Kevin Johnson

I think there are a lot of places where the problem could occur. It is easy (for me, for example) to forget all about snow being an issue in driving because I live just below the frost line in Florida. Carburetor icing problems have passed from people's memories because the modern automobile effectively counters them. Also because the people who have directly experienced the problem are getting older and passing away.

It is an issue for light aircraft because many still use carburetors and the consequences are a bit more serious. An aside: a drive in the mountains will place you at an altitude similar to that used by many light aircraft (an article below expands on this).

Remember, many of the hot-rodding techniques being suggested on the boards actually move your vehicle back in time technology-wise: a give and take situation.

http://www.vv.corvair.org/Library/benzinger.htm

A Speech by Robert P. Benzingerat the Corsa National ConventionSeattle, Washington, July 26, 1975

Robert P. Benzinger is a Professor of Industrial Design at Arizona State University. He was Senior Project Engineer at Chevrolet during the development of the Corvair engine, Design Engineer for the Corvair Engine between 1959 and 1962, and later Staff Engineer and Chief Engineer at Chevrolet until 1970 when he became associated with Arizona State University. The following is the speech he made at the CORSA National Convention in Seattle in 1975 which held us all spellbound until late that night.

-snip-

It was along about this time, too, that we had another nasty surprise. We had a road trip out in the fall of 1959, right after introduction. Early fall, almost late summer. We had a regular circuit for these road trips. We'd take off from Detroit for Colorado Springs and climb Pikes Peak to find what disasters were there. What wouldn't idle, what wouldn't start, and what wouldn't run on top of the mountain and so on. Then we'd fix everything up. From there we'd take it down to the desert Proving Ground in Mesa (AZ) and find out what a mess had been made of the hot weather running, by what had been fixed up on the hill. Well this particular year, '59, there was an early record breaking snowstorm in Colorado. The wet sloppy stuff came down in great quantities. Well the first day the fellows ran into this, they called in and said they were wasting their time. "We can't do anything in weather like this." "Do you want us to come home?" Well you scratch your head for a while and say "No you're three days from home. Stay there and do what you can." Next day they call up complaining bitterly about fuel pumps. The cars were starving for fuel. What on earth was the matter with the fuel pumps? Well we started off on a witch hunt after fuel pumps. (We) Panicked AC. "Send somebody up." "Get somebody out there at Colorado Springs." "Find out what's going on with your lousy fuel pumps." Next day they call in hat in hand. They said "We've found what it is." it's carburetor icing." Of course when you look at the design, everything that we had done and were so proud of to keep cool inlet temperatures in the hot weather and keep the air density and power up, turns into disaster in icing weather. That one, at that time was probably the worst icing car that ever hit the streets. So panic the program again. Dynamometer and cold room running. And of course that's where the heat pipe came from that goes down between the cylinders, up thru the turkey roaster and puts some warm air up there. For those of you who had '60's and were in icing country, you knew that this was almost a fix, It handled a fair amount of the icing problems, but when you got really into the rough part of it, when it was 33 or 32 1/2 degrees and 100% relative humidity, you were likely to be shut down by the side of the road anyway. It really wasn't totally satisfactorily resolved until the complete redesign with the damper doors on the outlet which recirculated air. From then on we completely forgot about any kind of icing.

Apeiron

I live on a mountain at 5,760 feet which in winter is often enclosed in low cloud and heavy fog. My car has cowl induction and no thermac valves or EFE or exhaust crossovers or preheaters of any sort, and I have never had ice form in the carburetor when I drive it in winter.

Kevin Johnson

That's wonderful!

Here's a link that talks about automobile carb icing in Canada:

http://w3.one.net/~watscarb/carb_icing.htm

Also, if you do a search, you'll get lots of hits regarding motorcycle carb icing in Canada.

philoldsmobile

OK, now i am realy confused! Carb icing can be a big problem for bikes, Kawasaki GPz 900R's had a recall for carb heaters, because the carbs iced on anything other than a hot day.

A work mate has a Ford Fiesta XR2 that he has stripped out for a track day car. It has a webber carb with an open element K&N filter. He has had to fit a length of hoover hose to the filter, running from the exhaust because his carb has been icing for over a month now.

Some people however, run edlebrock filters (or moroso etc) all winter and report no problems.

Do you think that the confined engine bay combined with the low cruising RPM mean that thirdgens are less prone to carb icing?

Kevin Johnson

Yes, that is a good conjecture. Low cruising RPM combined with the radiant heat from the motor. But I would take the cue from your work mate. Presumably he is driving in the same conditions you are and experiencing icing; it is easy enough to swap back to your open element when it gets a bit warmer.

philoldsmobile

That was my thoughts as well, so it is now in winter mode!

of course, while it was off it got a new hot air hose, and stripped to bare metal and re sprayed!

Any restoration is good restoration!