I was wondering what would be the best engine for the Sig 1/4 scale Cub. Would the Ryobi 31cc engine fit well in this plane? I was looking at the Zenoah G-26, but decided to go the conversion route for the cost. I have a lathe and mill, so I can make most of my parts. One other thing, is there anyone selling CD ignitions for these engines, and if there are, roughly how much do they cost?

Thanks.

-- Acer
http://speedwing.net

I would go with a Magnum 108A 2 stroke! That will over power her as it is!!

I am building one also. I am powering mine with a Magnum 120 F/S , with a 90 deg. header it fits well in the cowl and exhaust comes out almost scale. I know it is too much power but you dont have to fly full out and it is there when you meed it.

Thanks guys for the suggestions. I'd really like to use a gas engine though. I've been reading through these threads and am contemplating the Honda 4-stroke engines. I saw a great looking conversion here of the 25cc Honda 4 stroke. Since it is a Cub and has a 105" wing span, I'm sure I can get away with the slightly heavier weight of the Honda, but would it be to large physically to fit in the Cub?

I watched the Honda 4-stroke video on Carr Precisions site and I think I'm hooked! It was extremely quiet running and sounded great, much nicer sounding than the normal 2 stroke gassers.

Any other opinions?

-- Acer
http://speedwing.net

two after market ignitions you might check out are:
1) http://www.ch-ignitions.com/index.html
2) RCIgnitions (Ralph) who posts here regularly.

The Ryobi or the Homelite 25cc are good choices. I have a Homey 25 in mine and the power is OK. The cubs wing is certainly large enough to support the extra weight. I'd recommend moving the firewall back with either engine to assist you with balanceing the plane, And it would be a must with the Ryobi since the engine is very long. BTW neither of these 2 engines will require a CD ignition. Both will hand star nicely with the stock mag ignition system. But I would recommend replacing the stock carb for more fuel flow and replaceing the stock muffler.

Thanks guys for all the suggestions. I went ahead and bought a $99.00 Homelite "bandit" chainsaw at Home Depot. It looks like this will be the easies engine to convert since the stock carb is of the right size. I've also read that it is about as powerful as the Zenoah G38.

I'm going to build the Ultra Spad Stick to train with before taking up the Cub. This will be my first Giant Scale plane, so I want to fly for a while with an expendable giant scale first.

-- Acer
http://speedwing.net

Check out the GCBM R/C 25cc gasser at [link=http://www.gcbmrc.com]www.gcbmrc.com [/link] . They are on sale through December 24th for $195.00. A perfect match for your Cub.

I have been flying a Sig Clipped Wing Cub for 2 years now with an old Quadra 35. It is no light weight at 15lbs. Since I painted it and thought "heavy" when building the tail it balances just fine. It is overpowered for a Cub but not terribly. I already had the engine, but if I were to do it again I think a 25 or 26 cc engine would be better. Mine has a Bennett exhaust deflector, wow is it loud. I really like flying it but I wish the guys would stop yelling "timmmmmberrrrrr"