#1 favorite, periphral port, turbo 20B. (Mazda triple rotor Rotary engine)

#1 favorite Honda build, probably a B20Z. Resleeved, bored to 86mm-ish, block girdle, 9.0:1 forged pistons, Titanium rods, heavily ported P72 head, etc., all turbo'd out the ass.

I am considering building up a D13A2, for shits and giggles. Throw on a D15A3 head, Crower rods, overbored to 74mm to accept standard D-series pistons, a nice Crower regrind... you get the idea. Maybe I'd just stick to an EW5/ZC hybrid.