stunthanger.com
Engine basics => Engine set up tips => Topic started by: mike donovan on December 29, 2010, 04:08:33 PM
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As many of you are aware, I won an evo 36 here on stunthanger last month and promised that I would try it out and report back on the result. I mounted it on a midwest magician right out of the box. I used the smallest venturi and the tube type muffler. It was way too fast and seemed to want to run away. About half way thru the tank it started to surge. Ifound that the needle valve assembly from a Tower 40 RC would screw directly into the evo venturi in place of the evo spraybar thus eleminating the remote needle. This seemed to eleminate the surge. I found that a short piece of 7/32 brass tubing was a perfect fit in the small venture thus reducing the venturi to .187 ID. Then I added 2 head shims. The next day I took it out and flew it again and the engine run was just about perfect. The final setup was the above mentioned ,187 venturi, Tower 40 needle valve unit, 2 head shims, fireball hot plug, rich's brew 10/22 fuel APC 10/5 prop ground RPM at 10300. I think it runs as good as anything I own right now. I am very happy with this engine
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Great report Mike. Thanks. I need to know how cold it was outside when you flew. I need to know so it'll shame me into a couple test flights I need to do.....
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Thanks, Mike! I'm glad it's working out for you!
Big Bear
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Dave, I think the temperture was about 50 degrees the day that I flew the evo. we have been having some crazy weather here in central mississippi. One day it is 30 degrees and the next day it is 60 degrees. It even snowed a little bit the day after christmas. Snow is very rare around here. I hope your evo runs like you want.
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Today i dug my Evo .36 out of the engine box and followed Mikes example. Two extra head shims and the r/c needle from a OS fp engine. Smallest venturi, no extra restrictions, TT 11x4.5 prop. This engine has had about a dozen 4 oz tanks of fuel ran through it before, mounted on a twister and removed without flying because of vibration. I can honestly say i was pleasantly suprised at the results on the test bench today after mods. RPM was around 10,300 and engine just sounded smoother, had quick responses to pinching the fuel line, i believe stunt ready! Now to figure which plane to swap motors on or should i build one for it. :! Thanks Mike for your report !
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Today i dug my Evo .36 out of the engine box and followed Mikes example. Two extra head shims and the r/c needle from a OS fp engine. Smallest venturi, no extra restrictions, TT 11x4.5 prop. This engine has had about a dozen 4 oz tanks of fuel ran through it before, mounted on a twister and removed without flying because of vibration. I can honestly say i was pleasantly suprised at the results on the test bench today after mods. RPM was around 10,300 and engine just sounded smoother, had quick responses to pinching the fuel line, i believe stunt ready! Now to figure which plane to swap motors on or should i build one for it. :! Thanks Mike for your report !
HI Ray,
GO FOR IT! Build a new plane for it! ;D If you need plans, give me a call, or jump in the car and come on down. I have a few dozen sets of plans that the EVO .36 would be great in, profile or built up, OTS, Classic, Nos. 30 or "Modern"!! LL~ (seriously)
Bill
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...I added 2 head shims... rich's brew 10/22 fuel
I wonder if it would run well with no additional shims and 5% or no nitro.
Eastern European engines like MVVS are apparently designed for no nitro and owners are adviced to add shims if they use it. Could the Evo be similar?