The valve train is bound to come up, so here's
a page giving info on the valve train.
On a short stroke engine like this, the valve train stability and strength is VERY important. It's really the key top making an engine like this capable of surviving the rpm required to make any real power. The bottom end is also important, but is much easier to spec out- forged crank, good rods, light pistons and careful attention to detail along w/careful assembly will go a long way towards making the bottom end survive just fine.