Hi all I was thinking of putting A 21cc gas to glow engine on this. it has a 75 supertiger on it now and a lot of weight upfront to balance it out.The 21cc engine come out to about a 1.60 ci I thinkmabey a 14/8 or 15/6 propwould give it about 7000rpm I have about 1 1/2 lb of weight up front to balance it and the plane weightis about 10lbs. so what do you all think michael

interesting idea.   21cc is approx 1.3ci,   will probably work quite, but i'd say some serious throttle management.  I'd try a 15x6 on it first.  I'd be giving the whole airframe a thourough once over tho,   make sure its structurally sound first.

read this post first may change your mind</p>

http://www.rcuniverse.com/forum/m_8678594/tm.htm</p>

your right its 1.2 I read that post on the supertiger 2300 but i am not talking about high rpm i talking about torque am i wrong to think high rpm equals speed and torque equals power? or is it the other way around I dont want to hurt anbody at the feild or crash a plane I was thinking of weight I was thinking of a cheap engine I can always prop the engine if its to much speed and i see what you are saying about flutter its just an idea thought i would just kick it around and see what the experts have to say about it thanks michael

21cc wouldn't be outragous power for the Skyboly Kit. I have often thought about putting my Zenoah G-20 on mine

the large st are not high rpm engines they swing large props at lower rpm like the gas engine you are refering too. you need to think prop size for speed and thrust small prop high pitch is speed large prop low pitch is thrust.your diameter will be limited by ground clearence so start with the diameter that gives you good ground clearence and work displacement from there

you would have one advantage running the super tigre 2300,   you can run no nitro at all.  I run all my big tigre's on straight methanol/oil at 15% oil,   and they run great,  and if you buy your methanol in bulk you can get it about the same price as gas, saves you also running without ignition etc too.

I have run my supertigers on no nitro before but with the other engines i run i just buy regulator fuel makes it easer michael