There have been a number of experimentals running Mazda rotary engines, air-cooled VWs, Subaru boxers, and Corvair engines. I think there's a company that fairl

There have been a number of experimentals running Mazda rotary engines, air-cooled VWs, Subaru boxers, and Corvair engines. I think there's a company that fairly recently started making some good-looking Suzuki engine conversions, as well. Probably a ton I'm missing, as well.