they’re sweet because they are a great motor with tons and tons of potential… turbocharging anything that wasnt turbo before is going to cause popped motors and i bet most if not all of those dead motors were not rebuilt for boost. the RB was probably a sound alternative after spending so much learning about turbocharging a KA. That Said, cranking the boost up crazy high will cause it to pop even an RB. I’m not saying the RB20 is a bad engine… I personally just enjoy the KA better.