I can get a H9 CAP ARF for a good deal and wanted to know your thoughts on putting a Ryobi conversion on it. Would it be a good airframe for this engine? This is the 1.20 size 72" wingspan cap that is white, blue and teal in color.

Anthony that cap 232 it's a great flying plane, I have set up mine with zenoah G23 converted to electronic ignition, the plane has not awesome vertical performance but flies great. Sure Ryobi 31 and H9 Cap 232 it's a great combo. Don't worry about the weight of a gaser on it, it's a tail heavy plane.

I just saw a guy fly a H9 72" CAP with old Matt Chapman scheme with a Moki 2.10, and he still needed to put a bunch of weight on the firewall. Still, the Ryobi with magneto will be too much weight and not enough power. If you are dead set on the engine choice, either go with electronic ign, or convert it to glow.

That is what this plane is, old Matt Chapman 1.20 size. Not the 80" purple one. There is a club member with the 80" purple one with a Moki 2.10 and it has great performance. I can't imagine what the smaller one is like with that engine. I am worried about hanging a 60oz engine on it and making it too heavy. I don't want a tip stallin', snapin' monster for my first gasser. I want something that will fly good and not fly like a brick with an engine. Is that what this would be?

Anthony ; I have a Ryobi 31 w/C&H ignition on my H-9 Cap. It works ok , I'm not thrilled with the power out put of the Ryobi , but I'm in the process of finding more. I've read some posts where people claim 14lbs of thrust or more, I'm only getting 9 with an 18X8 prop. My plane weighs right at 14lbs without fuel , & still lands well. The thing you have to remember with a cap is to land it a little on the HOT side, they don't glide too well , especially with that kind of wing loading. Hope this helps

Well then.... you don't want a CAP, especially a heavy one.
Ron

Man there is lots of mods that make the 32cc ryobi a comprible motor just use a bigger carb and any rpm gain means a bigger prop either in pitch or diameter. If you get a bigger carb say in the 11.5 mm range you can increase compression by removing the stock gasket and use a silicone gasket maker. If you can find a machine shop that will take some surface off the crank case where the cylinder bolts on that would be even better for you. I bet you could get over 7000 rpms with a 18-10 prop which would probably give you 17 lb of thrust or so. If you take too much off the crank case then you may have to deck the piston and change the tranfer port timing. Good luck

what is the real big deal with gas conversions. I will tell you why, the 2 reasons are inexpensive fuel and no gooey mess. Here is what you do, take your ryobi get a glow plug adapter and a alcohol carb from ch ign. with a converted engine on 0% fuel only 2.80 a gallon you get more power and loose the weight and still no gooey mess because you have bearings on the rod.

simply put no mess,low fuel cost,less weight only 2 lbs., runs cooler and more power to boot.

check here for more info

http://www.rcuniverse.com/forum/m_61.../tm.htm#613466

You may have to do some kit busting too make it work, such and moving the firewall back. Sounds like too much work, I have the HANGAR 9 80 inch Cap 232 with a MDS 218. It has unlimited vertical, and still comes in under 14 pounds. I don't see your plane with short wings coming under that and you are going to have a really heavy wing load. That not good on landing gears, you find it hard not to pancake the gear or pound it thru your fuse. Mine has no bad habits flying and I have had three Caps of differing sizes. One I crashed going for the club record of aileron rolls and one succumbed to the dreaded trying to land with a setting sun. I have had other fliers suggest putting a just slight reflexed down pitch to my ailerons to combat tip stalls, but my caps haven't been tip stallers. Heck my 80 incher will land itself once place on final approach, have landed it many times without moving any controls perfectly down the center of the runway.

Will