Just out of curiosity, do many people use a carb setup on their
aviation Wankel's? Figured I'd ask since I've seen a few questions
regarding the standalone ecu for fi and not much regarding getting
a carb on the 13B (assuming most people use 13B's.)

Vlad

Not many. There may be one or two. The fact is an aviation carb
is as much money as a fuel injection system. I think Ken Welter
uses a 48 mm Weber carb. Webers cost over $1000 and are not easily
leaned.
Two 48 mm Mikunis might be had for less than about $750 total.

Paul Lamar


This is going to sound ignorant but I have to ask anyway.
Why not use auto carbs? Last I checked Edelbrocks were
about $300 shipped from Summit/Jegs.
Vlad

Well you can but they cannot be leaned at altitude.
That is essential for low fuel burn.
For awhile there there was a remote leaning kit available for
Holly  four barrel carbs. I don't know if that is still
available.

Paul Lamar

Hi Paul,
Just an off-the-wall thought for your comments. Can a standard
auto carb sit atop a pipe with an adjustable window downstream
of the carb? Similar to the way a propane oven burner or bar-b-que
burner mixes air with the propane gas. At sea level the window
is closed, and all air goes into the engine thru the carb and the
venturi does it's thing. At altitude, the window in the pipe
downstream of the carb is progressively opened allowing air to
enter, thus less air thru the carb. Less air thru the carb would
equal less gasoline sucked in by the venturi and a leaner mixture
arrives at the engine. This approach would "lean" the mixture by
admitting more air rather than less gasoline. I'm probably missing
something obvious, if this were so simple it would have been done
years ago by aeroengine manufacturers  : )  Any thoughts?   Dave M


------------------------------------------
Yes that might work but you might also loose fuel through the window
as the pressure in the intake pipe goes below and above atmospheric
pressure
on a regular basis per rev.

Ken Welter was fooling around with dynamic pressure effect
leaning. I never really figured out how his idea worked.

Unlike a car an airplane is always going at least 100 MPH so dynamic
pressure will be above static atmospheric pressure. If you feed
that from a forward facing scoop through a pipe and some sort of
valve into the intake pipe below the carbs that MIGHT work with
no loss of fuel.

Paul Lamar

I guess a reed valve could work. It has been extensively used in two
stroke engines, preventing blow-by of fuel mixture when the piston
starts traveling downwards.

My 2 cents,

Alfonso