The 1600 dual port VW engine can grow to 2.5 liters, at the extreme. The flat pancake, or Porsche motor, derived from the Porsche 914 never spawned the frenzy of aftermarket activity that the bug motor inspired.
It also never inspired the production activity in Brazil and Mexico.
If you were willing to do some minor modding, you could put Porsche power into the Type 1.
Buddy of mine did that.
extra power made it pretty scary, handling wise, almost as bad as the early swing axle cars were on 36hp