This is just speculation, but I have a feeling Mazda may keep the engine length the same as the Renesis and use a thicker center plate. It would give more options for a center bearing and provide more room for the intake and exhaust ports. Just my two cents.

 

So I seen a picture a while ago, I didn't think any thing about it, but these new pictures particular this one showed 4 holes in the crank lob

a while ago I seen this next picture and shrugged it off as a cool render, then I noticed the 4 crank lob holes, then direct injection so I decided it was a 16x render. but what intrigues me is right by the exhaust it looks like a black circle was drawn to hide something? a logo maybe, or more importantly a turbo?
you decided

 

Well spotted. Could be a turbo charger, the location of the oil drain coming out of the black 'circle' would also lend credit to that theory as well.

 

Unfortunately, I think that is just the Hydrogen turbo 13B Renesis concept they showed way back at the Tokyo auto show along side the naturally aspirated dual fuel Renesis that actually went on limited lease/production.

It was also direct injection and the 13B Renesis has the 4 holes on the E-shaft.

Note how the lower turbo one has 13B Renesis wide waterjacket on the periphery of the rotor housing that got filled in over the years for faster warm up (emissions).

See how the 16X pictured above has been designed from its inception with narrow, low volume water jacket around the periphery of the rotor housing.

 

so the Hydrogen renisis was more powerful then the stock one, wow!!! I wonder what turbo that is. it almost looks to big to fit in the car, I wonder if the motor placement was different in the chassy. if not, I wanna see there motor mount bracket!!!!

 

do you have any more pictures?

 

No, the naturally aspirated hydrogen/gasoline dual fuel RX-8 that was on limited lease was much less powerful on hydrogen than gasoline.

The Turbo hydrogen renesis was not put in a running chassis that I know of, I only know it from that concept display at the Tokyo motor show.

 

this should have been production!!!

 

I've been waiting 10 years, where's the 16X?

 

Given the events over the last three years, the Lord Jesus Christ is likely to return before the 16X ... seriously, no joke.