A little know fact regarding engine with removable front housing like Enya's -
"Its not generally known that an ENYA engine with the bolt - on front housing can very easily be made to run in reverse, simply by rotating the front housing 90 degrees to the right ( when viewed from the rear of the engine ). Why would you want to do this ? Well, I' ve been wanting to fly a C/L model with 3 line throttle control ever since I was a kid, and the information I' ve gathered suggests that an engine turning in the opposite direction to normal is highly desirable, as sudden throttling up will usually cause the model to bank in on the lines, due to torque reaction in an anti - clockwise ( viewed from the front ) turning motor. So, I contacted my ENYA friend in the States who is an engineer, Pat King, and asked him to check the shaft timing on an ENYA 35 - lll B, firstly with the intake upright as delivered from the factory, then with the shaft housing rotated 90 degrees to the right hand side of the engine - here are his findings
ENYA 35 - lll B shaft timing, normal configuration - With housing on the side ( reverse rotation )
Port opens at 48 deg. ABDC Port opens at 46 deg. ABDC
Port closes at 48 deg. ATDC Port closes at 50 deg. ATDC
Pat says that " The timing is so close that a dynometer is probably the only thing that could detect the horsepower difference ". Obviously, the shaft timing duration remains the same, so 5 minutes with a screwdriver and you can convert your ENYA to run in reverse ! Don' t forget to bolt on a pusher prop."
Gained from this site -
http://www.supercoolprops.com/articles/enya.phpBut something to watch out for is De Sax cylinder axis offset that will only work in on direction of rotation and perhaps venturi offset as seen on the likes of Super Tigres and MVVS engines although I doubt that this will adversely affect much.
If using a clockwise rotation be sure to visit up thrust as a trimming aid as opposed to down thrust when using the conventional anti-clockwise props.
Cheers.