Have a friend building our RV 4. I was originally going to put a Magnum 70FS, but now I'm thinking about a OS 61FX that I havecoming off another plane. Is this engine to big for this plane?
Thanks

I fly my RV-4 with a Saito FA-56 fouyr stroke and it flies great

I flew mine with a Magnum .46 two stroke and it was plenty of power. Mine had flaps as well.

I flew mine with a Magnum .46 two stroke and it was plenty of power. Mine had flaps as well. I have no idea why it double posted, sorry. Maybe the moderator will delete the second post. Thanks

Actually flaps is the reason I was interested in the RV-4 initially. It was great to learn to fly, see the reaction of the plane, add a little down elevator (eventually I programmed a 9% down elevator mixed with my flaps) ... and practiced slow fly-bys and landing with flaps although the RV-4 doesn't need flaps, they're still fun.

61fx will be a little heavy, if you want that size motor on it try HorizonHobbys new Evolution .60NX, Same size and weight for the most part as a .46 2stroke.

I think im going to toss a saito .62 4s in mine once its built (just got going on it)

I fly mine with a Magnum 70 four stroke and it works great. No complaints at all.

I am about to build one and put on a OS 55AX.

Did you have to cut the cowl to clear the head? Im pretty set on the saito .62 but if i can fit it without hacking i might opt for the .72

Yes, unfortunately I did but it looks okay with just the valve cover sticking out. Makes it easier to get to the glow plug since I don't have a remote driver on this one. I have the fuse hanging in a spare room so I went in and took a pic of it from underneath.

Hope this helps. It was a Great Planes kit. I built it with flaps and the plane flies and sounds great with this powerplant. The only complaint I have was some of the lite ply was not the best so I traced around the original and cut some replacements. not bad just two or three pieces.

I would still recommend this kit to anyone wanting some kit experience that might have one under there belt.

DM

After seeing this thread I got the fever and flew my RV4 today [&:]. It had been a year since I had flown it. It was great... I like to use the flaps, Iwas thinking about the Magnum 70 four stroke. I wanted to let you know that my model built extremely tail heavy and since I don't like to add lead if possible the 70 was on my mind at the time I built it. I wanted live weight, not the dead weight of lead in the nose. In order to make the plane balance I had to mount the 4.8 battery and the rx in the fuel tank compartment. Please note, that if you mount the battery and rx around the fuel, you should put each one it it's own seperate sandwich bag and seal the baggie with the little small plastic zip ties. I get them at Lowes or Home depot. Even with everything up front I'm at the rear of the CG range on mine.

Hope you find this helpful.
BTW this pic is from when it was first built. You will notice wheel pants on this one. Unless you fly from pavement, forget the pants,,, mine lasted MAYBE three flights. They are cheap plastic and grass will tear them up fast.

Thanks for the heads up! I'll try to built the tail light, excited to get it going, i love these airplanes!

A 61FX would be an overkill for this plane - too much weight and power for a model this size. Keep in mind also that this is a scale model and not a 3D airplane. I fly mine with an OS .46AX w/ Bisson Pitts muffler and I have just about unlimited vertical.

http://www.flickr.com/photos/brcf/3956366107/

http://www.flickr.com/photos/brcf/3956391307/

I think you're right. I'm going to stick with the 70 FS.

And the prop size?