Chris Newport wrote:

Aircraft carburettors are a completely different animal
to the automotive variety which do not have to deal with extememes
of both pressure and temperature as well as such delights as ram air
and carb heating. I never saw a car with a priming pump and dual mags.

They are no different in the principle of operation. There is no magic
in an aircraft carb, most of them used on small engines very much less
complex than automotive units.

The priming pump is not a part of the carb, automotive carb heat could
be said to be supplied automatically by the manifold heat riser, and the
carb doesn't know ram air exists, it only knows flow. The carb could
care less what the atmospheric pressure is, only the pressure difference
between the throat and the bowl (if there is one) and temperature only
effects the mass of the air passing through and thus the mixture
requirement.


Having driven a pair of Wasps for many years I appreciate your point
but I assure you that I always managed to keep them running sweet.
Thankfully they were replaced by PT6s which are a lot less tempremental.
[ You will probably be able to figure out which airframe this was, and
thus my probable age, but dont tell the group B-). ]

Beech 18 or maybe a Goose ... spent couple of years hauling mail in an
18 across the mountains of Montana. Will never forget the winters, never
care to repeat them either.

Rick