I am currently building full scale replica of the 1930's Fleet model seven. While most were powered with radials, some model 7's were inline inverted Gypsy engines of 90 HP. As both radials and Gypsy majors are hard to find and expensive, I custom built a Honda 1.6 all aluminum Civic, utilizing a homebuilt reduction drive having a standard 3" belt & cogged pulleys from a Harley Davidson. Photos avail very soon. Yes, lots of machine work, but with a drive ration of 1.7 should work out well and not too heavy, with the original Honda engine rated at 120 HP more than adequate for the Fleet biplane. This is now my third and likely my last homebuilt, let's just say bucket list Sonny Furman, Col, USAF ret.