Hi Rusty,  I think that is a 2 rotor in the photo.  For a single the entire drive could be lightened.  I like the use of the stock bell housing, and the fact that there are outboard bearings top and bottom.  It seems extraordinary well designed and built but then I am used to looking at my own work  which normally is lacking in both these categories.

 

Hi Jerry,

 

It’s a single for sure.  You can see the head of the tension bolt that runs below the exhaust port.  There’s clearly only one rotor housing there.  Another curiosity is what appears to be some sort of gear on front end of the engine. 

 

I didn’t recognize the stock bell housing, because I suppose that would be handy to be able to use.  I still be the whole thing weighs close to 60 lbs.  As for being lighter for a single, I recall something that Ken said about belt drives a while back.  If I recall correctly, he said it would have to be just as strong, because the power pulse is exactly the same, only less of them.  That kinda makes sense to me, but I’m an electronics guy J

 

Cheers,

Rusty (how do you like Autoflight drives <g>)