31 replies to this topic

[Jamie_RoverMini35]

carb icing is if the cars going a certain speed for a long time, say on the motorway particles of water entering the carb will begin to stick to the insides and begin to freeze potentially jamming the throttle

Suffered from that once on a fire breathing 1380 with a Webber. Accelerated down a dual carriageway only to find that when I took my foot off the throttle the car kept accelerating. An interesting few seconds.

oh dear that doesnt sound very fun, bet it sounded good though a 1380 with a weber, i love the sound of mine !

[CityCharlie]

People confuse fuel condensation with carb icing as at first glance the effects of the two seem similar. Heated manifolds prevent fuel condensing on the inner surface, they do nothing to prevent carb icing (the manifold should be isolated from the carb anyway). Air has a poor thermal conductivity, the freshly refrigerated and fast moving inlet charge will not be significantly (or even detectably) heated in the small time that a small proportion of it is in contact with the warm aluminium.

Just a question, but does it help with carb icing at all?

Not at all, but it could give a nice placebo effect.

The trouble with all this is the wording, carb icing is not the problem. Having a heated manifold, helps to keep the petrol atomised (mixed with the air). When the manifold isn't heated and the mixture comes into contact with the walls of the cold manifold. The atomised petrol drops out of the air (condenses back to liquid).

So from both of those quotes, you chaps reckon having the manifold connected is the way forward for a more consistent running car? :).