Recommend a Gas Engine
Two different charts, rcfaq and ThrustHp
Webra 120, 18-6 MA prop, 9100 rpm from rcfaq, 25.3 thrust from ThrustHp chart
RCS 1.8, 20-8 prop, 6800 rpm from RCS,21+ thrust from same chart
Something wrong with this picture.....
And the RCS is heavier than the Webra....