not air cooled, and am just going for the resemblance . using a turbo d inline four tdi vw. have been down the road of trying a guzzi behind it but twin disc is the weak point, then welded up spiders in a late model bug trans. but it throws weight offset and a size problem. have looked at some of the things the v8 guys are useing but monies and size are problems. the little ranger 2sp. is slick but not haveing the rpm band as the gassers use makes me think i ll need access to more gears. thought i found the right right angle drive unit, (honda crv transfer case) would work great for a right side trans. drive but backwards for left side trans. drive. still on the right combo search. think n if i can find the correct right angle drive unit to see if a heavy built v twin transmission and clutch would handle the torque. the tdi is built to 120-130hp and should be in the 230-270 torque range. we ll see.