Not true. The pump has the same dynamic range as it is geared from the Lyc
or Cont.
The lower potential rotary idle has nothing to do with it. You make an
approach
at the same prop RPM. Anyway I think my Continental will idle at 500 RPM :-).

BTW the Ross box Ed is using shutters badly at anything less than 1500
rotary engine RPM anyway.

Paul Lamar

Mike Wills wrote:

  Stated another way - If the pump is driven with  pulleys that result in a
1:2.17 ratio then it should be turning at prop RPM. So this should be
exactly the same as if it were bolted to a Lyc (assuming that the pump on a
Lyc is driven at a 1:1 ratio from the crank - I dont know if that is the
case). If a lyc drives at some  ratio other than 1:1 then you need to do
some simple math to figure out what the pulley sizes need to be to get the
right ratio on your 13B.

  Having said all that, forget the vacuum and go all electric. If you must
have vacuum it sounds like the smog pump is the way to go.

Mike Wills

 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org