Whizzbang....I did look at that, but I have the lower primary ratios (2.242:1) installed (and closer, lower ratio transmission gears), so my belt speed will be less on the engine primary reduction than it would be on the end of the trans (trans has overdrive). This arrangement is about as short as I can get, and certainly the slowest with a small pulley set. Also, this lets me determine where the engine rotations are, and eliminates the drag of "two overdrives".
I also had the advantage of guidance from people learning to make horsepower through two cranks. Pictured below are the flywheels (lighter on the "drive out" engine)....not a great pic...sorry. The front flywheel is quite a bit heavier than the rear; before you ask, I don't know why....just following directions! That's the good part about bein' not so bright; smart folks help you out, figurin' 'what can it hurt?'
The other problem for connecting output shafts, is the wacky layout on the "left" side of these engines. The shift drum is on the "wrong end" of the engine, right under the countershaft, plus shift linkage arms, flywheel, starter, starter drive, ignition...all in between the countershafts...gets ugly.
nrhs....yes, "A" class, and it'll be "APS" only, because there is too much gear in too small a space. There will be things hanging off the bike, all the way up into the fairing, which will make it impossible to enter as a naked bike. I'm still struggling with the dry sump pump (which is a MUST HAVE due to the rear engine lay down, which would flood the trans if I wet sump). I may have to open part of the front engine forward case area, to make room for the dry sump pump, bringing the lines out the side of the motor plate.
When I first ran Bonneville in 1969, I was fascinated by Don Sligers dual Enfield. To my eye, it was perfect, and I've dreamed of building a twin engine bike ever since. I don't know if it'll work as good as his did, but I'll always appreciate that memory. That's as good a reason as any to give it a try. Thanks Don!
JimL