In configuration the Wilksch is simple - but the major problem is that is has not been designed for simple production. The 'wrist pin' with a hemi-spherical cup and socket is a nightmare in production terms - and it gives issues in terms of reciprocating weight. A 'clever' idea but one whichhas crippled the engines potential
The new "big bore" Wilksch that is currently durabity testing no longer has the spherical cup & socket. The revised combustion system on the big-bore requires a shaped piston crown so will have conventional bearings on the connecting rods.
Dave