Paul,
here is an article from AUTOMOTIVE ENGINEERING Oct. 83 on the Mazda intake
design. For 5 - 6,000 RPM, plenum volume is two liters ( larger decreases
volumetric efficiency ) and intake runners are 500 mm from plenum box.
Measurements of an 86 13B give plenum box give ~ 7.75" x 3.5" x 4.5" =122 cu.
in. ( 2L ). Top Runner from plenum, ~ 11.0". bottom runner to end housing, ~
5.5". End housing port length ~ 3.0". Total = 19.5" ( 495 mm. ).

>From your post EXHAUST-PIPE-LENGTH.JPG with peek BMEP at 6k RPM the longest
intake pipe is 370 mm ( 14.57" ) + 3" port length =17.57" (446 mm. ) this
looks like the 12A engine which probably accounts for the difference in
length.
So, it looks like the intake pipes should be no more than 20" long, less for
peek BMEP rpm higher than 6,000.
Ed.    pebvjs@aol.com

 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org