Engine question, Not RC

Greetings- for nostalga resons, I want to build an 1/2-A U control from
1969 Sig Air Modeler.
Engine used is a K&B Stallion .049, or a TeeDee .049.
Both are as obssolete as I am.
Would an O.S. .10LA be a substitute, or would it be too heavy and
The plane has 19" wingspan, of 3/16 balsa by 3" wide.
Fuse is 1/4 balsa stick, about 1-1/2" high tapering to 3/4 " at the tail,
and 15 " long.
Would plan need modifying or should I scrap the idea and pick another plane?
Thanks, Jim
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That sounds like a _big_ engine for that plane -- you should be able to drive it around the sky with a .049 reed valve, so a modern .10 is way too much. I have a much bigger plane -- 26" x 5" chord -- that I fly with a reed valve .049. Flight performance is definitely trainer-like -- it has done 3/4 of a loop on several occasions, and 7/8 on a few, but never a complete one.
Do some web searches -- Cox 1/2A engines are still available, as are parts. One of Cox's biggest distributors recently bought out their warehouse, and has put the most popular engines up on the web.
If you want a new engine, Brodak sells a .049 that's specifically engineered for C/L.
Or if you _really_ want to diverge from the original, electric flying is starting to migrate into C/L. You need a timer (to replace the receiver), but with brushless motors and LiPo batteries you can get performance that's as good as a piston engine and if you spends your money right in some ways superior.
Reply to
Tim Wescott
(top posting fixed)
Uh, what's a CS .049 Sport?
In that size plane, I suspect that just about anything with .049 cu in displacement will work -- it's just a question of how _well_. A reed- valve COX will pull it fine, but it'll probably labor through stunts. A TD .049 would probably be the bee's knees (I dunno -- I've never flown anything but reed valve .049s). Norvel or Brodak .049s are probably at least as capable as a Cox TD, and lighter.
Reply to
Tim Wescott
On Wed, 02 Sep 2009 00:10:10 -0500, Tim Wescott wrote in :
It will be FINE.
I built a bunch of CL planes like these when I was a kid, helping my brother and his friends to learn to fly.
We had one or two good engines. We rubber-banded them to the nose of the airplanes, flew until we broke something, then moved the engine to the next victim in line. I had mounted the engine to a piece of plywood and put a dowel through the fuse to make a hitch point for the rubber bands.
You're not going to get precision aerobatics out of this setup, but it's not a precision design. 3" wide balsa wings say "trainer" to me.
Reply to
Martin X. Moleski, SJ

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