UMS Evolution Radial Care and Operation
#1202
Refer to videos of B-17's before start up (been there done that)
Lars....."Whew"
Tom.....Some Robinhood vid would be nice
Last edited by Dad_Roman; 08-08-2014 at 09:16 AM.
#1203
Like I said, I did mine by the book. These radials demand looking after, though not high maintenance, such an engine does need a bit of pampering. I'm not complaining as it rewards me with loads of power and a beautiful sound. I'm very particular about after run procedures and using after run oil etc.
You don't but one of these beauties every day!
I take the bottom two plugs out and let the excess after run oil drain out, before start up checks. Then clean off the plugs by lighting them up for a second or two.
You don't but one of these beauties every day!
I take the bottom two plugs out and let the excess after run oil drain out, before start up checks. Then clean off the plugs by lighting them up for a second or two.
Last edited by cymaz; 08-08-2014 at 09:18 AM.
#1204
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First runs should only be for 5 minutes or less - otherwise the engine will overheat, unless you have a cooling fan pointed at it. Mine broke in enough to hold glow on all cylinders after an hour, and could set the low end after two hours. Spent the last (third) hour trying different props, to hold down the rpm - figure it'll gain 10% in the air, so 6,000 max is ~5,400 static (on the ground). That'll depend a bit on the drag of your airframe & prop selection.
#1207
With all information it sounds like its hitting a lean spot to me (or maybe lean overall) but I will let one of the other guys chime in.
#1210
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Hmmm. Have to agree that it sounds like the high speed needle is too lean. What fuel are you running? If it has too much oil it'll be thick, and the carb may not be able to feed enough fuel to the engine at high speed. Any muffler pressure to the tank?
Last edited by redball8; 08-08-2014 at 05:10 PM.
#1215
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Ran the engine this evening. The engine would run at 5100 with the glo on.. Turn off the glo and it would falter. So I leaned it thinking it was too rich. It was and ran close 5000 with the glo off.. So I'm getting there..
I'll get the Hi speed dialed in and then work on the low speed setting.
I'll get the Hi speed dialed in and then work on the low speed setting.
#1217
My Feedback: (2)
Question, My needle valve retainer spring has some how broken. I'm talking about the one that is a friction fit arm that sits against the grove on the Carb. Needle Valve to keep it from rotating.
I don't see this as a part on the Evolution site or the Horizon Site.
Any Suggestions for a replacement?
I might try one from one of my other engines to see if it works, I'll let you know.
FYI. the engine is now running near 5000 with no glow assistance over half throttle. It's getting near broken in I think.
I don't see this as a part on the Evolution site or the Horizon Site.
Any Suggestions for a replacement?
I might try one from one of my other engines to see if it works, I'll let you know.
FYI. the engine is now running near 5000 with no glow assistance over half throttle. It's getting near broken in I think.
#1220
Join Date: Nov 2012
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tsnaylor1964
Okay, new member here. Been lurking in the shadows for some time learning about my evo 77 from some great contributors like maxum and others. Love my 77 and it runs and sounds beautiful. Pulled my asp 160 twin off the j-3 cub and installed this radial on her and boy, it is cool. 20x10 zoar prop, 7% evo oil with with methanol and no nitro. Use onboard glow with 4 D cell 10000 mha rechargable batteries wired for 2.4 volts switched with servo on 25 amp toggle. Like maxum, these engines have brought me back in the hobby after a 30 year absence. Hope this forum stays alive, would love to share info with others who enjoy these nice motors.
Tom
#1223
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Hey thanks Pappy. I was anxious to get the Evo 77 flying after six months running it on the bench and breaking it in. I first tried it on my Howard DGA-15 but at 24 pounds and 5700' elevation I could not get it off the ground. So I pulled the ASP 160 twin off the Cub and the rest is history.
What radials are you flying?
Tom
What radials are you flying?
Tom
#1225
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Maxam,
I bench ran and did the break in with a 24-10 prop but that was near sea level elevation. I fly at our ranch at 5700' elevation and it would not get more than 4850 rpm, even leaned out. I experimented with different sizes and pitch props and was able to get the best performance with the 20-10 zoar and 6050 rpm. Anyhow, I have a good excuse to buy the evo 99 for my Howard DGA-15 which is much heavier than the cub with less wing area. Thanks for all the great info and tips on running these beautiful engines, I learned a lot just reading your posts.
Tom
I bench ran and did the break in with a 24-10 prop but that was near sea level elevation. I fly at our ranch at 5700' elevation and it would not get more than 4850 rpm, even leaned out. I experimented with different sizes and pitch props and was able to get the best performance with the 20-10 zoar and 6050 rpm. Anyhow, I have a good excuse to buy the evo 99 for my Howard DGA-15 which is much heavier than the cub with less wing area. Thanks for all the great info and tips on running these beautiful engines, I learned a lot just reading your posts.
Tom