Paul,

On a previous post, I think you said that 20B engines are getting
scarce and expensive.  What is unique about them besides the crank?
Can you build a three rotor with 13B parts if you have a crank made?  I
noticed that Racing Beat offers a unique 20B end piece made out of
aluminum.  I think a three-rotor with aluminum end and intermediate
housings would be ideal for this helicopter:
http://www.vertical-aviation.com/

By the way, did you get a chance to go through that website on the
Cessna CH-1 helicopter?  It uses an engine installation that would make
an automotive based engine simple to install and it has a very elegantly
simple rotor head.

Steve Brazil

Please don't send html messages. It screws things up down the road.

The 3 rotor intermediate housing is unique as well as the shaft.
The Aussie have a special 3 rotor shaft and center main bearings
so 13B intermediate housings can be used to build 3 or four rotor
engines. You can also buy a 3 rotor from Mistral as they are making
all the parts.

I read the site but I saw little on the rotor head or dwgs of the rotor
head.