I had in my mind for some months that a S6 motor was the best type over the S4 and S5 versions to use for high boost applications because



1. Carbon graphite coated rotor housings for 32% less friction

2. Better cooling for spark plugs in the rotor housings

3. Better crank trigger accuracy

4. Better oil pump, more oil capacity, regulator and pickup system

5. Different eccentric shaft and larger thurst bearings for less bending on the front

6. Ribbed side housings much stronger

7. Better intake, plenum and runners for volumetric efficiency

8. Port timing in piston engine speak has more "lift" and "duration" on its combustion chamber events

9. Factory hardened stationary gears



I currently have a S4 or a S5 engine depending on whom you ask, or perhaps a mix match of the two.



With the rebuild I am planning on new housings. Should I pay the extra for S6 housings over S5 or S4 housings for the benefits?



Should I keep my end plates and center plates if they are ok, or should I get S6 end plates and center plates?



My application is road use and amateur circuits on weekends with high boost (20-25psi) T66 on 98ron fuel and water injection.



Im a technical person and Im nervous because (1) I dont know of any good rotary engine building books written by the likes of Jenkins or Yunik in the piston world (2) My budget doesnt allot for catastrophic failures (3) I dont know many people running high boost 13BTs (4) Ive only been into rotaries for less than a year



Ive been thinking about using the S6 housings, with clearanced rotors on the GURU stationary gears with no snap rings as I told later motors dont need it. Using the GURU stid kut instead of dowels. I thought it maybe possible to machine the center plate for a bearing and modify the eccentric shaft to reduce the flexing on shaft. Higher oil pressure with Mazda comp bearings. Rotary aviation 2mm apex and solid corner seals with Virton / silicon o rings. Turbo extend port inlet and exhaust. Run premix delete OMP. Heat shrink the tension control bolts.



Im trying to do all the research I can to avoid mistakes. I really dont mind some of the more experienced people critising my plan because at the end of the day I'd like to get it right the first time. Mechanics are not qualified engineers and these gaps in experience and theory bothers me.



Looking at the probable engine builders dyno results he maxes out at around 7950-8000rpm and I thought a 8400rpm rev limit would be appropriate for the ECU to cut out at.

I have also been wondering about this same thing. S6 is the 13B-REW, correct? I would assume the REW to be the best. https://www.nopistons.com/forums/pub...IR#>/boink.gif

Im not one to assume, particulary when its my wallet paying for it all https://www.nopistons.com/forums/pub...DIR#>/cool.png



Id imagine that post S6 like the S7 and S8 RX7s also had other changes to their esign.



Whats certain is that there is changes and that makes a difference to choosing which one for engine builds.



Cmon all you experts help me out please. I was hoping for a relaible 500RWHP 13BT using 98ron pump gas, WI on an intercooled T66.

With all you seem to have researched and discovered, I see you have the answers to all your questions. Isn't now more than obvious that the S6 is the strongest of the lot, go ahead spend the luchi:).

Mate I dont have the details to the answers. And I dont have many examples / experience as well. I was hoping people who have been down this road might lend their opinion https://www.nopistons.com/forums/pub...IR#>/smile.png