Hey Jim,
It does look promising, doesn't it? I'm not going to prepay for one, but will wait until they come out and I know that I can squeeze one into the cantilever frame. There is still a bit of room, but not much. The footprint is close enough to not matter. So long as the height isn't an issue, then it should work, but I'll happily let you buy one first. Ha! I have a new 79cc I was going to use on this new build I've started, a 53 Schwinn I'm building wheels for with a moped drum hub up front, 12 g spokes and 52 rims. Rear hub is a Bendix coaster. I'm using a 1960's Herculese (Sachs) moped front fork and have an in frame tank made for it out of electroplate tin. It will get a matching tin transmission cover. If that Predator engine will fit it would be a welcome bit of extra grunt on these long and steep hills in north central Maryland. With the 79cc I can make most of them without pedaling, but pulling a trailer with the dog drags it down some. Whatever the actual displacement, it is putting out more than the 79 so that has to help. Hope it works out.
SB