Dieter Hartmann-Wirthwein must be a full cousin of Willie Wortel. He says he is not a web designer or writer, but he is doing well in his workplace.
For example, he made four-valve heads for his classic racer, a BMW R 50 with a Kaczor bicycle part. He had the crankshaft made by Kurt Manigatter.
Knowing more? Take a look at www.wirthwein-motor.de