QUOTE
why not design the heads OHC? 4v?
That was my first thought.
Second thought: How in the hell do you install the rods onto the crank?
Obviously the pistons/rods have to go in through the head side with pistons pins installed. Then you slide the rod over the crank and install the cap... How do you tighten the bottom nut?
(edit) perhaps you could install the crank with the rods already installed & torqued, feed the rod ends through the hole with the cylinders Not installed, install pistons, feed pistons through bottom of cylinders. Might be enough clearance...
third: 2000 HP on an aircooled engine...hmmm Methinks that the heat generated would not work with an aircooled engine but there i go using that thermodynamics voodoo again ;-)