David,
A liitle off the Kaos topic. Are 90 sized 2 stroke engines allowed in Vintage pattern events? I just started running the OS GT15 (gas) in my grandson's TeaCup (mod T-Clips). A sweeter runner I have not experienced. It's on muffler only so far (I will check it out on a pipe at some point too) turning a 14-8 apc at around 9000. Very good performance for an 8 lb airframe and extremely quiet (engine is soft mounted); I'd guess overall output to be similar to a well tuned glow 60 but not exactly a good comparison.
Matt,
glad to hear it! I've been interested in the GGT15 as it might reduce the engine weight somewhat given the lack of the ignition unit.
I'm not really the person to ask about regulations and restrictions imposed by the different pattern associations as I don't participate in them given I'm in Canada. That might change some day.
That said, I believe in order of restrictions, the VRCS followed by the SPA and lastly the CPA are increasingly tolerant (or decreasingly restrictive) to power and model specs. I believe the SPA restricts power to 1400 W (glow or electric) but whether gas power is allowed or not I don't know. If I'd have to guess, I'd say it isn't. But surely some SPA member can offer better insight on this. The CPA, would likely allow it provided the power output is comparable to a piped glow 60 which I suspect it is. There is more emphasis on model design in the CPA, from what I understand, than there is on power plants. I believe span is limited to 6' = 72". Scott can answer re the CPA in detail but I think the gas 15's might be doable.
David