I really like the Honda GC engine in Neck's pic, above. The GC160 on my pressure washer is always just a hearbeat away from going into a mini, but I need it to wash stuff. They are so unusual w/the belt-drive overhead cam, non-removeable head and diagonal split on the cases. Evokes two of my other favs, the Rotax flat track bike engine and Offenhauser Indy car engine. Didn't some Bugatti engines also have a non-removeable cylinder head? Northern Tool has GC160s for $229, and GC190s for $279.