Well let's do a thread rather than making the ranger thread even harder to follow I had grabbed a 23hp vanguard v-twin the other day at a garage sale. Attached to a siezed up trash pump for under 100$. EFI, 12v electric start. Did have that ranger in mind - as it's a project I wouldn't mind right now. Some reading and googling tells me there's just about everything available to make these work as aircraft engines. Everything from Pistons, sleeved cylinders, billet/cnc/forged/cast rods and hundreds of cams to choose from, stoker kits, I did see mention of a dual sparkplug and larger valve head option over on a lawnmower racing page. There's actually some details on turbo (using that geo metro 3cyl turbo) and smog pump superchargers odd as that sounds. Spin on oil filter, says we've got some oil cooling options, on top of just air cooling. It's interesting how many options are out there, and it seems fitting to maybe start talking about what's needed to make one work for that the ranger design.