SOmetime this year I'm going to start building a Balsa USA 1/3 scale D-VII. The plans call for a 50cc to 80cc engine. I would like to use a twin cylinder engine (horizontally opposed or V-twin if possile. My reasoning for using a twin is to reduce the vibration that a single cylinder engine might cause. The engine bay is just under 9 inches wide internally, and about 11 inches wide if measued from the outside. I was leaning towards the Fuji 8BT 86 twin, but it's about an inch too wide

Thanks in advance.

-Jorden

Any idea of what this thing will weigh?

That Fuji is adding a lot of dead powerless weight on the nose. I think you would be amazed at how smooth a Tarus 50 (single cyl) or the ZDZ 80 RV (again a single) are... especially teh Taurus.

I agree with all of the above. About the only twin choices left would be a 3w-56 if you could find one.

Thanks for the suggestions so far. I have a 3W-56 for my Balsa USA Ercoupe, and it's too wide too. My search continues ...

The smoothest running single is the Taurus ts52. There is no lack of power so that's not an issue. Twins only come so narrow and I don't think you will locate anything that would fit unless a Zenoah GT-80 would go, and I seriously doubt that. The Fuji, well, there's just no reason to go there.

http://cgi.ebay.co.uk/HH50T-50cc-TWI...QQcmdZViewItem

What's the issue with the Fuji? AM I missing something?

I've seen two dealers for this engine in the U.S. so far. United Hobbies has it for $325, but is out of stock, and www.lsproengines.com
also has it, for $470 (yeah, same engine) I talked to a guy who had rated it on the United site and he really liked it, He sent me a video of it running on a test stand, sounded and looked great.. I'm looking hard at this engine for a build I have going. It's the narrowest engine I have found in the 50cc range. From plug tip to plug tip is 8-1/2", plug cap to plug cap is 9-1/4". The guy at LS Pro says he can narrow it even more by using a smaller plug and caps, at extra charge. I only wish the plugs came off the back of the cylinder instead of the top (angled) as my concern with fit is clearance above the engine to my cowl.

The only other one I can think of around 50cc is the Roto twin. Look at it on RC Showcase site.

Is that a rear carb engine? You would think the ZDZ 80 would fit in the cowl being as it has a rear carb.

I don't see that twin 50 flying this plane well. The plane calls for 50-80cc.... that 50 twin puts out a lot less power than most 50s on the market.. combined with the extra weight makes for an unhappy underpowered airplane.

This little Chinese twin only weighs 3.75 pounds, including the mufflers and ignition. But I agree, 50cc is the very bottom end of the range, and I would recommend the upper end of the range, given what I've seen on the 1/4 scale D-VII. It will fly on a G-26, but no power reserve and performance is marginal. With a G-38, though, it is a great performer.

If you go with a good 80cc single you should hit the mark. The Super 80 ZDZ would be an awesome engine., also give you the ability to spin a large prop.

Mount the engine at an angle, one cylinder up and the other down say at 30 degrees or so. See if the cylinders will clear the engine cowl

I am assuming you meant 4.75 pounds? It also turns a 22x8 JXF prop between 6000-6200 which is like 1000 below any quality 50.

I would def. still consider the Taurus 52... agrueably the strongest 50 on the market and definately the smoothest.

If you like your women obese you'll like a Fuji.

This is a link to the LS Pro in a 16 pound plane. Just click on the Green plane. Very smooth, only quit once in the air, I ran out of gas. http://lsproengines.com/default_013.htm

Your absolutly right about the GT-80.Mine is 10 inches wide from plug boot to plug boot.Even with short plugs your only going to get 9-1/2 maybe.

Well, I like them thick with phat bottoms, but definitely not obese

Thanks for the heads up!

I thought about that too, but since the engines prop hub exits the cowl in the lower half of the cowl, I don't think there's much room for rotating it.

Thanks,

-Jorden

Do u have one of these engines?

I've got two.