Derrick-RCU

My Feedback: (1)

I have just finished framing up my Great Planes Super Decathlon kit and have bought a new OS.46fx and bisson pitts muffler to power it. I also have a Saito .56 and was beginning to wonder if this would be the better engine for this plane? I have yet to drill the firewall for the engine mount so I still have a choice. I was wondering if anyone has flown a GP Decathlon on a Saito .56?

I am still leaning towards the OS .46fx but just wanted some input on if the Saito .56 would give the same performance as the .46?

bdphil

My Feedback: (26)

I don't know about the saito 56 but the OS 46FX is plenty for this plane. I'm recovering mine right now and thought about switching to a 4-stroke, but the 46 works fine.

Ben

bash-ace-RCU

My Feedback: (16)

I think it flies best with an O.S. .70 FS in it. The .46 will give you good speed, but the .56 might give you a better pull through maneuvers.

MinnFlyer

My Feedback: (4)

Which ever engine you decide on, make SURE that this plane is not even the slightest bit tail heavy. I have seen and heard of several of these that met their demise on the first flight due to a snap at the wrong time.

bash-ace-RCU

My Feedback: (16)

Minnflyer is absolutely right, don't let that big high wing fool you, this plane is capable of some crazy aerobatics, I knew a guy that practiced all his pattern routines with one due to our grass field not being suitable to his pattern planes landing gear.

flatspins

I would strongly recommend sticking with a 2 cycle on your decathalon. I owned one a couple years ago and had a saito .65 on it. It was so torquey and the tail moment of the plane so short, i almost crashed just trying to take the thing off. After flying models for ten years prior, i'd be surprised if anyone less experienced could've handled the four stroke torque on that model.
Switched to a 2 cycle and while i wasn't estatic about the plane, it performed better. Ground handling was still pretty squirrelly, but i didn't have to deal with the added problems of a big prop up front creating too much torque.
I hope you have more fun with your decathlon than i did mine, I put it up and haven't flown it since that season.

Derrick-RCU

My Feedback: (1)

Thanks for the responses so far. One of the reasons I built this plane was because of all the stories I have heard about how easily it tipstalls, should make for a fun snap roll, spin type airplane. I wanted the classic looks of a high wing airplane without totally falling asleep while flying it.
I think I will stay with my original plan of the OS.46fx, although I really do like the sound of the 4 stroke.....if I had a 70 sized 4 stroke sitting at home I would have not had to ask this question as it would have been the engine of choice, but I am a bit concerned about under powering the plane with the Saito .56...

MinnFlyer

My Feedback: (4)

If you want somethiong that will snap, you've got the right plane.

Just hope that you can STOP it once it starts!

stesta5074

Im curious to know the direction you guys mounted your engine on this plane. I am building one and am getting ready to plan the instalation of the engine. I have a .46fx. Did you mount it upside down to maintain the scale lines or did you guys cut a hole in the side of the cowl.

Thanks,
David

bash-ace-RCU

My Feedback: (16)

It's easier to install a Pitts style muffler if the engine is side mounted. Mounting inverted limits your in cowl muffler options, plus increases the chance of engine damage in a nose impact situation.

Derrick-RCU

My Feedback: (1)

I have managed to find some time and have finished the building stage of my GP Decathlon. I am now starting to cover it.
I ended up going with the OS46fx and have mounted it sideways with a bisson Pitts muffler.

wildthng

I have one and it is the goofiest plane i have ever taken off.In the air it snaps so hard you will think the wings will snap.Its a lot meaner than it looks.A 46 2 cycle is a good match for this plane.Thing can be preety wild.A cap is a *****cat compared to that thing.

DGrant

My Feedback: (4)

My Decathlon is as wild as "wildthing's it sounds like. As everyone stated...do not let the high wing fool you. This a short coupled, old time, high performance design, that will tumble, spin, snap, all at the same time. When throttled back at altitude it's just like most, however, point the nose up and start getting with the sticks, and you will put on your own show. Have fun, these can be a challenge, that's what it's about though..right.

PS, I'm running an ASP.61, and an APC 11x8(<---I think) prop, it's either 11x7 or 11x8 anyways.

Stans Fibertech carries nice cowling/wheel pants for these too. My ABS cowling cracked after 2 flights, oh well...the fiberglass is holding up very well though.
I don't fly mine to much though, I havent flown it in probably over a year...It's here though, when I want a challenge

John B

My Feedback: (1)

I think the 56 with a 11X8 would be a killer match for the plane, recently replaced a tt 46 on my stick with a saito 56 and the 56 does everything better. Sellin off the 46's

Edwin

My Feedback: (2)

Got a OS.46fx in mine with the recommended CB Tatone pitts muffler in it. Great combination. All the above comments about snapping are the same with me. You want a snap happy plane? This is it. This is a very performance related plane, a real sleeper. It can be pretty evil at times. I've found that the bulk of my ground handling problems start after the landing gear speads a bit. Turns it into a ground looping. Squeeze them back together a little and its ok for about 4 or 5 more landings. Right now mine is down for recovering and replacing the nyrods and new lander gear. It developed a recentering problem over the years, going back to pushing rods. And I hate moneykote, new covering will be solartex and paint.
I built some floats for but decided to wait on that experiment.
Edwin

peterbannon

I power mine with a Saito 65, flies great.

http://uk.geocities.com/peterbannon/Decathlon/DecathlonStart.htm