I was wondering why the intake ports on the 13b are on the face instead of the side of the rotor housing. Wouldn't the intake on the side allow for a longer amount of time to draw air? Also, you wouldn't get the start and stop motion of the air but a semi continuous flow.

 

my guess is a combination of noise, relatively high idle, fuel economy and emissions. i remember reading in a couple places that the old 10A (R100, th original Cosmo/110S) were peripheral ported, but i have yet to see decent photo of a 10A engine to see for myself.

however, run a search on peripheral ported engines (use: "peripheral port*" or "PP") and see their characteristics. you can also contrast them with the 13B Renisis ...

some people enjoy them on the street, i don't think i would. however, i don't see Mazda ever making them for their rotary streetcars - not wise, inexpensive and possibly not legal (due to emission standards).

 

Only the Cosmo had peripheral ports. The R100's 10A had side ports.

 

thanks, Jeff