stunthanger.com
Engine basics => Engine set up tips => Topic started by: Robin_Holden on January 09, 2010, 11:25:29 AM
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A very Happy New Year folks from a very chilly Charente in S.W.France.
Advice please regarding the expected launch RPM of my 'older ' engines.
I have several older engines , which are usually run on a fuel mix of 25% lube' , usually 18% castor , 7% synthetic with 5% nitro. I am using MAS 10X6 props' and uniflow R/C plastic tanks. I am also using tongue mufflers.
My 'best/reliable' launch RPM's are as follows :
ENYA 35 [ 5224 ] : Around 9,000.
OS 35S : Around 8,800.
Fox 35 [ 40th and 50th Anniv'y ] : Around 8,600. [ With all castor 27% ]
Do these appear about right guys or should I be expecting someting better please ?
Much obliged for any contributions ,
Robin [ ex-pat Brit in the Charente full of ex-pat Brits ]
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Hi all.
AFAIK, they seem right figures, approximately between 8.500 and 9.000 (mainly depends on the load fron the prop) is a good launch....might be in the edge between 2 stroking and 4 stroking (more or less) and settle back to 4s after a lap or so.....
Hope it helps.
Regards from Spain
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As said, sounds about right. I'd suggest you try a handful of different brand props around the size. Prop makes a lot of difference to how the engine runs and how the airplane flies. I've been running 11 x 5's on my Fox stunt 35 for a good while now.
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What brand, Jim?
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Much obliged for the contributions fellas ,
Thanks ,
Robin.
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At the moment I am running a Taipan. I've run Zinger wides in the past. An APC 11 x 5 seemed to be a little too much. An APC 11 x 4 was OK, but not as good as the Taipan.