Concerned about engine selection
#1
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From: ardmore,
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I am getting back into the hobby after several years of absence. I have my old anniversary cub all tuned up and ready to go, and plan on using it to get my skills back. I have spent the last several years messing around with helicopters but am ready to get back to my airplanes.My current project is a Bud Nosen Jenny with an 8 foot wingspan. I have had this kit for over 30 years and decided to build and fly it. The kit was originally designed for a 60 powered two stroke engine and I am planning on using a Saito 91. I tend to build heavy and have concerns if the 91 will have enough power to get me out of trouble if I get into it. If I had built this plane 30 years ago I probably wouldn’t even hesitate but it seems everything I see now has gas engines in the 20 and 30 cc class. I know the total weight has a lot to do with the power selection and I do not know the weight of this airplane right now. I have been looking on the Internet for several months now and cannot find many Nosen Jenny’s around. I don’t know if it was not a very popular kit or what but I have not been able to find anything to reference as to what other people have done.My question is this, can anyone give me a rule of thumb for selecting a power plant for this airplane. In other words, is there a chart or rule for weight versus power? I plan on weighing this airplane as soon as I can but right now I can’t tell if it weighs 10 to 12 or 20 to 22 pounds. Also, I assume the total weight to use for this calculation will include the weight of the engine.Any suggestions or help would be appreciated. I'm sure this airplane will fly with the 91, but just don't want to put myself in a position I regret (Not to mention I'm dying to try a gas engine).ThanksSteve
#2

I have only seen one; that was about 1980. Is it suppose to be direct drive or use a Maximzer with the 60? I would say a 30cc would be what you would want.
#3
I would start by looking at 26-38cc gassers.
As Tff states, back in the day, a gear reduction unit was used to allow larger props, and smaller engines to be used. These days, better options are available to us.
As Tff states, back in the day, a gear reduction unit was used to allow larger props, and smaller engines to be used. These days, better options are available to us.
#4
Do some research on new Jenny's and what they are flying on. It doesn't matter who the designer was, only how big and heavy the plane is. Here's one similar example that Google turned up on the first try.
http://www.maxfordusa.com/gm-jenny-105-soild.aspx
http://www.maxfordusa.com/gm-jenny-105-soild.aspx
#5

A 50cc would pull the wings off a Nosen; but I bet it would hover great. I dont think there is a piece of spruce in a Nosen kit, all balsa. No matter what engine, the nose area will have to be modded. The one I saw was top notch with details and it wafted around like a 2 channel glider. One of the first giant scale planes I ever saw.




