ORIGINAL: DarZeelon
Reggy,
Here is a much better, larger photo; from which one can see the details.
This is a wrong crankshaft! If anything, Hirtenberger should have used a 180° crankshaft, to achieve even 360° firing intervals and a much, much better balance.
The con-rods would also be more conventional; instead of the 'knife and fork' arrangement.
This engine, as designed, has 180°/540° firing intervals and a single counterweight...
These engines were not built by HP but by Dietmar Kolb from Germany
Here is the engine from my collection