On 9/14/2005 2:15 PM, xyzzy wrote the following:
snip

Bottom line, Pipers need carb heat a lot less than Cessnas because of a
different air induction system design.

Cessna 172's need carb heat pretty much all the time below a certain RPM
(it was 1800 in the last one I flew) because they don't route their
induction air as close to the manifold so it doesn't get heated as well.

On the runup with a Piper when you check carb heat you get a lot smaller
RPM drop than a Cessna does. This is because the Piper's air is already
pretty warm.

I think you've just described the difference between Continental and Lycoming
engines, no? This is a Cessna with a Lycoming, where a single casting functions
both as the intake manifold and the oil sump.