You know what's funny? I've seen and heard plenty of people that had issues with the 353, but not nearly as many had them with Nova's Plus 12 (at least once you figure out what temp it likes to run at). Go figure.

Back to the topic, I think OS Speed 12 XZ has the best top end speed when gearing properly.

To be honest the club races( most famous ) here won a 19 years old guy with xray nt1 stock and RB R3 stock... So its true and i saw it R3 is one of fastest .12 engines. In the track were even nova's and picco's!!

i see 12 xz-t has 1.75hp power ....................................amazing

Most horsepower numbers are false. I would go off of on track performance. Most of the modified engines out now are so close in power that it comes down To gearing and tuning. The fastest motors I have seen were xxl3 balanced,Murnan rbm3, Murnan 353,jp to3-t&jp eagle tl3-t, Murnan +12sct. I will Admit os has stepped there game up new .12 engines and .21 engines are fast as hell for the price. Just pick one of these motors and you won't lack any power.