Go to an airshow this summer and listen to a P-51 Mustang takeoff. The Mustang is powered by a Rolls Royce designed, Packard built 1,650 cubic inch V-12. Another sweet sound is any V-12 Ferrari from the '50s-'60s. Lastly, a big-block Chevy with a healthy mechanical cam with clattering steel rocker arms is pretty hard to beat.
Oh, and "Victory by Design" on Speed Channel usually has some nice engine sounds as the host, Alan DeCadanet, drives vintage sports cars through pastoral settings at high speed.
