The images above show the chronological steps in the rebuilding of my 20B 3 rotor engine. The motor has been street ported and all intake and exhaust ports have been opened and CNC machined. The block was also strengthened by the addition of extra dowel pins in each rotor housing. This will help keep the block from twisting and jamming the apex seals. (Why the motor was rebuilt.) The conversion from the factory twin turbo setup to a single, larger turbo facilitated the need for the extra dowels pins. As you can see in the above images, attention to detail was a priority. The apex seal grooves on the rotors were enlarged from 2mm to 3mm and the apex seals upgraded to dual springs using stronger truck corner seals. All other gaskets and seals through out the engine were also replaced. Next after about 1000 miles of break in, it will be time to tune the newly upgraded Microtech ECU in real time on the dyno.