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Author Topic: Hop up tips for Cub .049A engine?  (Read 1024 times)

Offline frank mccune

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Hop up tips for Cub .049A engine?
« on: January 29, 2021, 10:16:52 AM »
     Hello:

     Does anybody have any information re. improving the power of these engines?  If so, kindly share.

      Tia,

     Frank

   

 

     

Offline kenneth cook

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Offline Dan Berry

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Re: Hop up tips for Cub .049A engine?
« Reply #2 on: January 29, 2021, 06:51:02 PM »
http://www.flyfreeflight.com/Site/Home.html

He can make them real zippy. Until the crank breaks or it just wears out the piston/cylinder.
There is a reason everyone flew TDs for so many years.

Online Larry Renger

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Re: Hop up tips for Cub .049A engine?
« Reply #3 on: February 03, 2021, 09:24:26 PM »
Forget the extra head gaskets, Cubs have low compression. Substitute a Cox RTF needle assembly for the Cub one, clean up the crankshaft port and bypass entry holes and there you are. I have used up to 60%+P fuel with good results on small props and no failures with these mods. Oh yes, I also did a bit of grinding to improve crankshaft balance, chamfered the venturi entry a bit and rounded the exit hole from the crankshaft. Just touch up stuff, probably not much of importance.

After dealing with the hideous needle valve design, cleaning up the flow and balance seem to be the key to Cub performance. Followed by the fact that it has low compression. Hmm, unless you can’t get Nitro, is this a problem? 😜
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

DesignMan
 BTW, Dracula Sucks!  A closed mouth gathers no feet!


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