The guy's name who's in both videos and who made both bikes is John Buddenbaum. He's a fabricator who mostly works with vintage 4-wheel racers. The approximately 90cc Maytag motor (45cc per cyclinder) he pretty heavily modified (narrowed) to make it work for bike power but still has only about .75 - 1 hp. The VW/Honda frankenstien motor has a displacement of around 260cc and puts out about 2.5 - 3hp, mostly due to the atmospheric intake setup he has.
He built both those bike during the same time frame that he built a 50cc streamlined motorcycle that he set the world speed record at Bonneville last year.
Jeff