During an episode of "Jay Leno's Garage," Jay was asked why classic European, and indeed, U.S. engines were all so different from one another in terms of horsepower, torque and redline. He explained that differences were the unintended consequences of arcane tax laws.
"MossMotoring" just published this excellent article that explains in detail the evolution of engine design with regard to early tax laws.
https://www.facebook.com/PoserMotorSports/posts/1673475739391762 (https://www.facebook.com/PoserMotorSports/posts/1673475739391762)