Michael Burke wrote,
New kid on the list.

Hi Leon and All,
It's clear that air filtration is required for the rotary engine to protect
the apex seals and rotors.

Just had a few ideas that may, or may not work and could possibly work with
a ram air scoop. (1) An old idea is an oil bath where incoming air hits an
oil pan before being inducted into the engine. No use for aerobatic
aircraft. (2) Is a new idea, I'm sure you've all seen those new cyclonic
filter free vacuum cleaners, that always maintain 100% suction, or so they
say. Could an air plenum be designed on the same principle so that dust and
gravel get separated from the main airflow and get ducted out a side tube,
leaving the main air stream to go to the engine.
Just ideas guys,
Michael.