After working on it since the first part of September, on the 16th I completed a model of a Comber rotary engine, using plans taken from the book "Elmer's Engines". Although it would spin free and easy when turned by hand, it refused to even try to run when air pressure was applied, even up to 120psi. Needless to say I was quite disappointed and did not know what to do about it. Good friend Mike Nay came to my rescue. He searched the HEME website and found other builders of the same engine had experienced problems and solved them with slight design changes. Those changes would have been so easy initially had I known about them, but a major rebuild now, but then what good is an engine that will not run.
Shown in the above picture is the engine rebuilt with a 1/16" larger cylinder bore and 3/16" smaller rotary valve diameter. WOW, what a difference it made. The engine runs very well now on almost no air pressure at all. Take a look at the video below.