During assembly of an aircooled VW engine it is vital to dial the axial play for the crank.
The optimal value is between 0,10 mm and 0,15 mm *edit: the correct values are 0,07 - 0,13mm!* There are shims to be added between the crank and the flywheel. A variation of 3 shims with different thickness to finalize the value. Luckily those shims are availble in a wide range from 0,24 mm to 0,38 mm in 0,02 mm steps. I think I almost did it spot-on, right in the middle of the range: