I have a Sig Senior Kadet with a O.S. .61 FX and I'm looking to change the engine to something that uses less fuel but still plenty of power.

I was looking at a Davis Diesel conversion but that requires a special mix diesel right?

Are there any Gas engines small enough that run pump gas that are not to heavy for a Senior Kadet?

This plane needs plenty of power because it has is own GPS microcontroller self guided flight system. (School Project) But we are looking to extend its flight time, i.e. use less fuel. Any Suggestions?

How heavy is the plane. Your probaly looking at about 6lbs built out of the box. My kadet flys great with a .46 OS FP but is not a speed demon. It gets great duration on a full stock tank. The engine rating is .29-.40 cu. in. 2-Stroke. So a .46 ABS ball bearing type engine with a speed prop such as a ASP shoud satisfiy your requirments.

couple of months ago there was a thread going in the giant scale engine forum with a guy who had a senior kadet powered by an echo 21.2cc trimmer engine.
look up the "don't forget echo" thread in this forum and check out av8tor's echo 16cc project. the conversion came out nice and light and was done as a replacement for a .60 size engine in an existing model.

dave

Hi,

Yes, check out that thread. I had a blast doing that conversion and I'm very happy with it. The 18cc Featherlite engines would also be a good option. These engines are easy to find, and a bit lighter than my Echo/Kioritz 16cc.

Have fun!

AV8TOR

I'd bet it would work. One of my students brought out a Senior Kadet with a .46LA on it. It took a full allen wrench set, half pound of led, and a pair of plyers to get it to balance. Later he filled a plastic box with some rocks from the parking lot since I wanted my tools back. It flew very well on that LA. Had to see it to believe it. Correct me if Im wrong but, I think that Kadet had something like a 80" ws.
Edwin

Thanks for the info. Yes the Kadet has a 80.5" wingspan.

I was looking at the Featherlite engines and they weigh about 51oz or 3.18lbs. My plane with the OS .61 FX already weighs in about 13lbs with the avionics on board, plus I'm adding 2 - 4 lbs in camera equipment. The .61 engine does fine getting the plane off the ground and seems to have plenty of power, but I will be flying at high altitudes, 4,500 - 10,000ft and possibly in high winds. Also the .61 goes through Glow fuel real quick.

With a featherlite engine I would be concerned of the plane being to heavy. Does anyone know how many lbs of lift the Kadet generates?

Also are there any downsides of a Diesel conversion? I have heard they greatly increase fuel efficiency? Is this true?

I think that with CD ignition instead of the magneto, you could get an 18cc Featherlite down to less than 2.5 lbs.

AV8TOR

Wow, you are really flying high!
Way beyond visual range huh?

Anyway, wonder how did the Diesel conversion go?
Did you try it on your OS61FX?