I don’t know a ton about foreign motors other than surface level stuff like the 2JZ, Wankel, etc. so please forgive my ignorance outside of US motors.
However, in my eyes, it doesn’t get better than the simplicity and easily available power of the SBC, BBC, and 6BT. What are your all time favorites and why?
Aprilias V4 engine. It sounds like a NASCAR V8 mixed with the soya grizzly bear would make of you kicked it in the balls. Noise and fury.