What causes the carburetor to ice up. I have a Ford Holly 2 barrel (2110) and after about 1 min the carb will start to frost over. Anyone know what causes this?

 

has to do with the venturi effect when air passes through the carb it is passes from a large opening to a smaller and then gas is added causing more temp drop some engines use a carb heat from the exhaust man to carb almost all aircraft with carbs use carb heat

 

did you block the cross over on your in take manifold

 

Exactly what I was going to ask...

 

I guess I don't understand what you mean by blocking the cross over on the intake?

 

There is an exhaust passage that runs under the intake from one head to the other to warm the incoming gases. Some folks block/restrict it to prevent the intake paint from burning in that area or for perceived "high performance".

If you are unaware of it, you probably have not blocked it.

 

Thanks, I have not block it. I'm running 292 with 3X2 I rejected the primary carb from 52 to 55 and the two secondary to 48 and that seems to fixed it.
Thanks again!

 

that would do nothing the weather changed and fixed it for now.it happends around the freezing point.the problem was solved in 57 when they hooked a heat passage to the breather which went to the exhaust manifold.

 

I have the heat passage and it was 60 degrees here when it started doing this. I have seen it happen like you mentioned before. I have a old Hot Rod magazine printed in 1957 and they talk about how to setup a 3x2 by jetting them properly. Any way, it's not doing it any more the outside temp is in the 50's Thanks,

 

Technically, it is related to dew point. It can happen on a warm summer day. I'm glad that you seem to have it under control. Did the article also mention carb icing? I'd be interested in reading that.

 

This is the closest answer. Usually carb icing will only happen when the temp is around freezing and the humidity is just so. Pilots will see this more often than those of us who are grounded. If you see carb icing on a V8, something is amiss. You're getting a lot of heat because of the carb being on top of a big heat pump.


http://en.wikipedia.org/wiki/Carburetor_icing