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How Big?

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Old 08-13-2013, 05:32 AM
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wildwillie3
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I have two OS 160's and was wondering if I were to build a twin war bird, what size of plane would I have to build?

Any idea's guys......

I don't have one picked out yet but was looking for some guidance.

Bill
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Old 08-13-2013, 09:04 AM
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R8893
 
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Check through the Don Smith, Nick Ziroli, and Jerry Bates plans catalogs. I suspect you will come up with about 110" span for a hotrod; a little bigger for something like a C-47. I'm thinking about a Ki-83 with two Super Tigre 2500's. (1.5 cubic inches). 1/6th scale.
Chuck
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Old 08-13-2013, 01:23 PM
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Chad Veich
 
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Jose at Fliteskin offers a 100" span DeHavilland Hornet and his prototype was equipped with two 1.60s. I imagine it had plenty of power but might give you some baseline to start with if you're considering a fighter type. As noted above the bomber and/or transport types can be substantially larger if you are seeking scale type performance.

http://www.fliteskin.com/DHHornet.html
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Old 08-13-2013, 02:51 PM
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BMatthews
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The new(er) FX160 2 cycle or the old four stroke 160?
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Old 08-13-2013, 03:38 PM
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wildwillie3
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The newer FX two strokes.

Bill
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Old 08-13-2013, 07:01 PM
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As a start you could try this;
  1. Pick some models that do well with the engine as a single that have performance that you'd like to emulate in your twin.
  2. Take the average wing area of those designs and double it.
  3. Work on the structure so that the weight comes in at double the average for the singles or within 15 to 20% max over double. This would be OK since the added size increases the Reynolds Numbers and thus the allowable wing loading for good performance goes up. But you'll lose climb performance if you let it get too far.
  4. Add a spot to put the two engines on this new "double area/double weight" design.

Yer done. Just build and enjoy.

This is the method used to build the DH Mosquito of WWII. They took a look at the Spitfire and wanted a longer range twin to mimic the Spitfire's performance. This led to two of the Spits Merlin engines mounted on a plane with twice the Spit's wing area and *****g out at double the weight with double the wetted skin area. The results spoke for themselves.
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