Tom Kendall wrote:

Here's one that undoubtedly has been kicked around before, but I haven't
seen it in my 4 weeks of lurking:

How are people installing vacuum pumps on rotaries to run gyros?  Or are
there any?  EFIS or air pumps to run pressure (instead of vacuum) are
alternatives I suppose.  The vacuum pumps I've seen seem to be designed for
torque loads only (by having a face flange mounting to fit a Lyc or
Continental accessory case).  No provision for the radial loads that the
overhung shaft of a belt drive would create.

>From what little I've gleaned on vacuum pumps, they can be cantankerous and
short lived if not treated with a lot of care in installation.

Tom Kendall

Dave Atkins has been flying now for several years with a smog
pump as a vacuum source. Kind of heavy at around eight pounds but
very reliable indeed. Greg Richter uses a small Chevy econ car
diesel alternator and adapted an air craft vacuum pump to run off 
the back side of it. Normally it has an air pump of some sort.
On his way from Atlanta to OSH that was the only part on the
airplane that failed. It was also the only certified aircraft 
part on the airplane as well :-) Here is a picture of Greg's
engine.

Paul Lamar
 
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