TZ Rules
I've just replaced my N12LL3 and My RB V12 with an OS 12 TZ! The RB is a great engine for a small to medium track. I hated the N12LL3! The old Novas with the CNC piston are better IMO. It lost it's pinch too quickly and just didn't perform. I never thought i'd be saying this but the TZ kicks both their butts! Long and short tracks. It's a little beast, easy to tune, durable, and a great engine all round!
p.s. rc-mushroom.com has the Novarossi NS12 3 port for $175. That is a deadset bargain. It has a CNC piston, not microcast crap!