The 3W-80 weighs .6lbs more than the 3W-50: that's 70% more HP for only 13% more weight. Your post is a brilliant example of the kind of wisdom that having a single repository for the facts alleviates.

My aircraft is more than 100lbs; I'm using two of whatever engine I choose. It will fly fine with engines in the 50cc range, however at this scale using a larger engine adds negligible weight so it will certainly also fly fine (better) with 100cc+ engines.

I realize this is unconventional, but I'm certain that there is enough information here to prompt a valuable exchange of ideas. Of course, all I asked for was prop and RPM data, but hell...



Mark,

I don't see how I was vague. I asked for prop and RPM data for a specific list of engines. At no time did I ask for estimations of performance based on my (admittedly) vague application, or for any other information that required knowledge of my end-use. The responses I got suggested that it was either impossible to choose an engine in this way (which is untrue) or that I was not qualified to do so (also untrue). I'll start a thread later to satisfy curiousity, if thats what this is, but for the time being all I wanted was engine data.