A friend of mine has an S4 Non-Turbo motor for sale, but I'm trying to stay away from the baffles in the exhaust port.



I couldn't find the information of which motors have these baffles. Anyone know off the top of their heads?



Thanks

 

None of the turbo motors have the baffles, and all of the non-turbo motors do. Thats from Mazda, but if you get one thats been apart and rebuilt with turbo rotor housings, or exhaust sleeves, or just had the baffles ground out, it would be an exception.

 

Sigh,



Ok thanks, I was hoping to avoid those baffles for porting reasons obviously...

 

Only if you are talking about the FC engines.



I have never seen a 12A with the port diffusers (they are not baffles!), and the 1985 GSL-SE engine in the garage has no diffusers either. I do not believe the RX-8 engines have diffusers in their exhaust ports either.

 

20b has baffles, some say they are to direct exhaust flow but the end of the day its a baffle

 

Good point. I was referring to FC engines only, since that is what the thread starter has.



Heres the webster definition of baffle - 2 : to check or break the force or flow of by or as if by a baffle

And the webster definition of diffuser - 2 : a device for reducing the velocity and increasing the static pressure of a fluid passing through a system



Regardless of what you call it, the inserts do seem to fit both definitions...

 

The cosmo 13b-RE has a exhaust sleeve that functions to recirculate exhaust gas into the intake stroke.