Whats the all up weight of the 3W24 with all its support gear? including Muffler, ignition, battery, switch harness, anything else needed to make it run. The RCS 140 is just shy of 3 lbs including a large Great Planes engine mount. It wont turn the bigger props like the 24, but it may have a higher rpm with the smaller props. So it may come down to what prop size you can apply to the plane in question.

You might want to check out the new Zenoah G26 also. First reports are looking very promising. I dont have one yet, but claims of around 9000 rpms on a 18-6 sound good to me. Here again though, it won't turn the higher pitch props like the 3W 24 is reported to do.

Kevin