can u bridge port a 3 rotor engine? and also where can i buy a stock reman 3 rotor or 2 rotor

 

Yes, the same bridgeporting principles apply to the 20B as they do the 13B. There are a bunch of places you can buy 3 rotor engines. Most just sell used ones with low mileage (< 30,000) but lots sell rebuilt or modded ones too.

Check these out:
www.atkinsrotary.com
www.pineappleracing.com
www.rotaryengine.com

Read a bunch of posts in the 20B forum for more info on all of this.