[steve86]

Wankels have trapezoidal “pistons”, just not reciprocating ones and generally called rotors.

“en.m.wikipedia.org › wiki/Wankel_…
3 photos
The Wankel engine is a type of rotary piston engine and exists in two primary forms... “

[TexasGator]

“Wankels have trapezoidal “pistons”, just not reciprocating ones and generally called rotors.”

So, it doesn’t look like a Wankel, then.