carb temp upper limit

[Zacke]

Hey guys,

isn't there an upper limit for the carb temps with the 3350? There are no markings on the gauges.

Didn't pay much attention to the carb temps so far because the Connie has no intercooler flaps. On the other hand one must not use carb heat with high power because of the risk of detonation.

Does anybody know how high the carb temps goes with T/O-settings?

Thanks in advance,
Zacke

[CAPFlyer]

Theoretically, there is no upper limit because CAT will rarely exceed the static air temperature on its own. Because of where CAT is measured, the air has already been accelerated somewhat, so it typically has at least a few degrees lower temp than the surrounding air. The introduction of the alternate air (air from inside the cowling) is what allows Carb temps to get above what it would otherwise be since the cylinders will heat the air well beyond the static temp. All you will see by having the carb heat on HOT during takeoff is a significant reduction in performance and power. There is a slight chance you might get some detonation if it's too hot (i.e. full carb heat at the hottest part of the day in the middle of the desert), but for the most part, the fuel/air system can cope with those increases and decrease fuel delivery to compensate.