ORIGINAL: coronabob
I will buy a RS60T when you get your production going. Currently, I have more single 50cc's than I can use. A twin makes less shake and I like that.
Question: why not 70cc? I am sure that you have run some calculations to determine the tradeoff between power and weight. Is it your goal to achieve the same power to weight of a good 55cc in a twin? more or less?
Hi,
Highly appreciated your support. With regards to your questions,
The idea for the twin is to cut down vibrations yet provide comparable power output to single 50cc class engine. After quenching those numbers, 65cc or even 70cc will be slightly over power (theoretically). So the idea for 60cc came about and the additional weight (against the 55cc single) is within a good margin ( at least based on my 3D illustrator software). The 65 or 70 the weight is a bit too much (but not that much also..) and to have a good ratio of bore against stroke, the cylinder head will be a bit longer than typical 50cc class airplane cowlings.
I think everyone here knows that the best possible location for the plug is dead center, this pose another problem i.e. the plug cap will be jutting out from cowling's sides... this will in turn favor the 60cc against 65 or 70. In fact i've tried to square the ratio(between bore and stroke), the output seems to be slightly less torque, don't really favor this, as i'm thinking of to spin at least 22 inch prop at 7200rpm therefore for pro-long cruising flights in excess of 1 hour a steady 3000 to 4000rpm will make the engine as reliable as it can be.
On the above note, my other intention for this engine is not only for typical RC aircraft but for UAV development as well.