There was a French short shaft homebuilt design driven by a Suzuki GSXR motorcycle engine and chain. The guy left the clutch inside the geared engine and used sprockets to achieve the final adjustment. Had more than 800 flying hours last time I've seen it.Thanks for all of the info. I didn’t reply sooner because the discussions quickly went over my head. I could in no way do the suggested math required and could only resort to trial and error which some posters suggested against. Also, although I could handle a little extra weight, the discussions led me to believe that a 5 foot shaft system would add enough weight/complexity to put the idea outside of the design mission. There is a design ( French I believe) that uses this setup with a BMW engine. It is a really nice looking aircraft and I’ll try to find pics of it and post. My design objectives required extremely light weight and unexcelled visibility. I could go with a swept forward wing but I really don’t like that idea. Thanks again.
Bear in mind also that chains&sprockets lose only 2 to 3% efficiency, while belts 10-20% and shafts 20-35% efficiency. Hence if you prefer some KISS solution, it might be wise to see if you can use some simple and proven concepts.