Modern Harley engines are outstanding for reliability, most unmolested motors I have seen are over 100,000 miles before the top end / piston and rings are done. [These are not throttle rod bar jockey's] Harleys ARE Built With a chain drive speed reducer! Belt drives are a rage of after market and Race machines as far back as the 60's. With any aircraft repurpose engine a tear down and inspection is mandatory. Set up timely inspections for certain wear parts, ( maybe use gear drive cams to eliminate the timing chain) Cruise at 3200-3400 rpm all day long - every day.... at 100+ lb ft of tq at your crank, x 1.4 bdsr = 140 lbft , 75 hp at about 2800 prop rpm. Good baffling around the cooling fins, wrap the pipes in glass tape, (may want to relocate the carb to prevent icing [ airbox near the exhaust tube] http://www.aeroconversions.com/produ...arb/index.html This aerovee unit may be a replacement for your carb, unless your going HD fuel inj. If you look close a HD engine appears to be but just 2 cylinders of a Radial aircraft engine
EZ Flap is the high performance upgrade for Cessna, Piper, Stinson, Maule and Beech manual flaps.
More performance - more control - more visibility ! 100% Money Back Guarantee www.ezflaphandle.com
If you look even closer, it is nothing like an aircraft radial at all. Keep in mind a motorcycle duty cycle and aircraft duty cycle are completely different. A typical full dress harley will use about 18 horse to cruise at 65mph. The knife and fork roller bearing connecting rod system in a weak link, and tapered pin crank does some downright scary things.
Why I continue to try to educate people.... The Twin cam uses a pressed round pin, That can easily be welded to the flywheels after they are set and balanced. Out of the Thousands of bikes and bikers I have associated with, I have never observed a properly set of flywheels move once set up. [improperly and too many 12 packs worked on them, a couple] ....... A Harley with rider has far worse aerodynamics than a brick! Go look it up. Touring bike 2 up with a trailer runs the hi-way hours on end, thousands of miles, year after year.... Far more load at cruise than a LSA.
You are right, I was thinking of the pre TC cranks before the cost reduction of the pressed pin type. I always felt welding the cranks was a poor idea due to the carbon content of the parts and the relaxation of the press caused by heating. I just couldnt do it, I work with too many guys that worked in harleys engineering dept durring the TC "development" to ever feel comfortable flying behind one.