RE: Sig Cap 231 : what engine: IMAC
Choice of engines is not bad. Have seen the Moki 1.35 in use in a 72" giles 202, flew great, lots of power. I have a Sig Cap but I have a Moki 1.8, Bisson muffler, 5% nitro, extra oil. Presently using a 20 x 8 Moki Prop at approx 6,500rpm. Unlimited vertical at 12lbs, 6oz.