1/3 Scale J3 Cub - Engine Recomendation
#2

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It all depends on what it weighs. I have three of these planes which I use as research aircraft and they are nice flying planes.
I flew one with a 3w-75 single cylinder with lots of power and we used to fly it up to 2500 ft agl to take atmospheric readings. Takeoff wt = about 50-55 lbs.
A second one had a 3w-85 twin. A little more power but a lot smoother. The 75 single is rated at 7.5 hp and the 85 twin is rated at 7.8 hp.
If you just wanted to putt-putt around the sky cub-like and your weight remained below 40 lbs, I think a G-62 would be the right amount of power. The kit is rated for a 50 cc gas engine but I think you would feel more comfortable with a little more power.
The current versions that I use are equipped with slotted flaps for slower landings and powered with 3w-106s (the same modeltech planes above which have been altered). Takeoff roll at 65+ lbs is about 20 ft with flaps lowered.
Hope this helps
Elson
I flew one with a 3w-75 single cylinder with lots of power and we used to fly it up to 2500 ft agl to take atmospheric readings. Takeoff wt = about 50-55 lbs.
A second one had a 3w-85 twin. A little more power but a lot smoother. The 75 single is rated at 7.5 hp and the 85 twin is rated at 7.8 hp.
If you just wanted to putt-putt around the sky cub-like and your weight remained below 40 lbs, I think a G-62 would be the right amount of power. The kit is rated for a 50 cc gas engine but I think you would feel more comfortable with a little more power.
The current versions that I use are equipped with slotted flaps for slower landings and powered with 3w-106s (the same modeltech planes above which have been altered). Takeoff roll at 65+ lbs is about 20 ft with flaps lowered.
Hope this helps
Elson
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My 1/3 scale cub was the Hazel Sig clipped version with a 120 inch wing span. The plane weighed 27 pounds and flew very well with a Kavan 50.
#7

I'm building a world models 1/3 scale J3 Cub ARF as we speak....I decided to run a Zenoah GT 80 and cut the cowell to expose the top of the 2 cylinders and plugs. Alot of guys are running g62's and they claim that it is plenty of power. These are weighing in at 26-29 lbs fly ready. I wanted alittle more power so when I put it on floats it will have the power to get me out of trouble if need be.
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if your going to fly on floats, there is no such thing as too much power. Im running a D&B 3.7 twin on my Balsa USA (twenty years old I might add). Good combo on floats. I think the Zenoah 80 twin would be ample also. I live in michigan on a lake and would like to have a float fly some day. Anyone in the surronding area, your more than welcome
Henry
Henry
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I ordered a DZY 48 twin gasser for mine....... I sure hope I did the right thing, as you all seem to have a bigger engine than me. Mine is also the modeltech cub.
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Ive seen guys fly 1/3 scale cubs with old quadra 35's. It doesnt take much, so Im sure youll be fine. I wouldnt have gone with the motor I did, but being as I wanted a big horse for floatsl, I went the D&B 3.7 twin. I originally was going to go with a zenoah 80 twin, but couldnt find one when I need it. Their cheap too consindering what i paid for the D&B.
#11

Thanks for all the posts/information. I received my G62 today ...... and the wraparound inverted muffler. I am also using the 2 inch prop drive extension. It all fits nicely in the cowl (but I will have to cut a small hole one side to allow the carb to stick out a bit). Bob
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im also boilding the balsa usa 1/3 scale cub.thanks for the ideas on the engine.i was going to go with the g62 also.sometime i would like to put it on floats.....so....................that engine should i go with ya think?everone happy with the engines they choosen?
#13

I have seen several fly well with the OS FF320 Pegasus 4 Cylinder engine. It looks good too, and the only holes are for the cylinders, and that looks scale (kinda-sorta)
Bill, AMA 4720
WACO Brotherhood #1
Bill, AMA 4720
WACO Brotherhood #1
#14

Just finished fitting my cowell around mt GT80. Looks great with the cylinders exposed on both sides. Can't wait to get it in the air.
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World Models 1/3 scale Cub, ZDZ80B2 engine, Robart main gear, BTE tailwheel, Smartfly power distribution, regulators and battery share, Skywriter smoke. Link to the construction photos, (Plane named in honor of "Crashburn T. Throttlebottom"). So far 32 flights.
http://www.flyaways.org/photos/2007/planes/wm13cub
http://www.flyaways.org/photos/2007/planes/wm13cub
#16

ds1rc....Your Cub looks great! I finally found time to finish mine and I have put 12 flights on it this weekend. Runs Super nice with the extra power to get it out of trouble at the blip of the stik. My Cub will fly KE great and do nice flat spins as well as great hovers! Will fly scale like a champ and will also take off in about 1.5 feet!!! I'm not exadgerating! I will post a video of a hover soon. The Zenoah GT80 is awesome! I had Ralph Cunningham of RC Ignitions convert the engine back to gas and install Electronic Ignition. (My engine was a used Alcohol unlimited racer engine when I purchased it)
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bzyguy01
You know that inverted stuff makes all of us old guys look bad. You will enjoy many flights with this Cub. The cross trus construction is a lot stronger than it looks. Have fun and fly safe.
Don S.
You know that inverted stuff makes all of us old guys look bad. You will enjoy many flights with this Cub. The cross trus construction is a lot stronger than it looks. Have fun and fly safe.
Don S.
#18

Thanks Don....I have a 33% Edge by H9 w/ G62 and it has alot of power with that plane. It will actually hover it at 22-23 lbs. So those of you that are wondering.....I think the G62 will fly the J3 better than scale and still have reserve power to get you out of trouble. I'm going to put floats on mine and still want extra silly power and this is why I chose the larger GT80 engine. I have plenty of vertical performance but not unlimited vertical. It will hover but not pull out ....J3 kinda harriers out if you know what I meen. I do think that the GT80 is one of the best choices for the Silly pilots like myself but way not necessary for the scale pilots.
#19

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ORIGINAL: BalsaBob
Thanks for all the posts/information. I received my G62 today ...... and the wraparound inverted muffler. I am also using the 2 inch prop drive extension. It all fits nicely in the cowl (but I will have to cut a small hole one side to allow the carb to stick out a bit). Bob
Thanks for all the posts/information. I received my G62 today ...... and the wraparound inverted muffler. I am also using the 2 inch prop drive extension. It all fits nicely in the cowl (but I will have to cut a small hole one side to allow the carb to stick out a bit). Bob
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well I hve been flying mine quite a bit recently, and it turns out the DZY 48 twin is plenty and some.
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Thanks guys. I did find a source for the prop extension, Horizon Hobby, imagine that 
The G62 is mounted, slimline muffler installed, linkages, ignition, etc, all rerouted and its ready to be run up tomorrow. If that checks out, its maiden time on Thursday.

The G62 is mounted, slimline muffler installed, linkages, ignition, etc, all rerouted and its ready to be run up tomorrow. If that checks out, its maiden time on Thursday.
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What are you guys with big cubs using for prpellers when you float fly? I have read that you should not use wood props. I have a Stihl 65cc four stroke in mine. I need a recomendation in a 23x8 that is suitable to float fly.
Thanks
Mark
Thanks
Mark
#25

Don't about his, but the 65 cc 4 stoke was used for back pack blowers, I considered doing a conversion some time ago. It may be used in other tools.