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May 03, 2019, 06:11 PM
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I have it going 34,100 now.. A lot of work went into that
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May 03, 2019, 06:13 PM
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That prop is a 4.6x3 cut to 4.312x3+a skosh, I tried adding a hint of pitch on the gauge.
34,100 now. My altitude is 5135 here, I wonder what it will do at sea level
Last edited by toad007; May 03, 2019 at 06:21 PM. Reason: added comment
May 03, 2019, 06:22 PM
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So in the vid it was 4.6 or 4.312
May 03, 2019, 07:51 PM
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I have that same program. that vid is 4.6 prop.
I will get more vid in the morning, seems my phone can capture that in that light.
I will get vid of it on this 4.312 dia. in the morning
Last edited by toad007; May 03, 2019 at 08:03 PM. Reason: added comment
May 03, 2019, 08:45 PM
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Awesome sauce look forward to it. Yes I keep consistency by using the same calc for all testing so the variances can be noted with accuracy.
The prop mod yielded 97 mph pitch speed 18 oz thrust so giving up some top end speed for consistent speed. The engine should unload to 41k +
with that prop / 116 mph pitch speed + The engine can certainly go past 50k I have done it, how long it would last at say 42k should be a reasonable
number past 60 before the conrod wears loose. I use 20% castor thus far for the engine it seems to do fine with it and for sure will aid in longevity.
Perhaps 14% and 8% synthetic to help keep the castor flushed out.

What is the exhaust timing?
May 04, 2019, 10:03 AM
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Ya know, Ive been so consumed with the cranks, I haven't timed the ports yet. I know going down in stroke effectively raises the timing, Right now, the sleeve is in the stock position, I haven't jacked it up yet. For a pipe, I think to get more blow down a guy would want to cut the exhaust port some instead of raising the liner with shims.
May 04, 2019, 10:16 AM
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If you cut the exhaust port, I have noticed that the Nelsons have a large arc on top as well as others that angle it down a bit. I believe it has something to do with the piston hanging up on the port ever so slightly.
May 04, 2019, 11:00 AM
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I wont be making a piped version. Maybe some day. Arc-ing that port in the middle up and angle to get over 170 is wise. Probably no need to cut the whole length of the port to get where ya want. Too much to do as it is right now for me. I'll leave that to someone else
Last edited by toad007; May 04, 2019 at 11:14 AM. Reason: added comment
May 04, 2019, 11:57 AM
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Here is my latest vid, I dont know how to rotate, trim etc,
picco 34k run (0 min 32 sec)
Last edited by toad007; May 04, 2019 at 12:10 PM.
May 04, 2019, 12:49 PM
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That run was done at 5135 altitude , the temp was 62f and the humidity
was 24%
Last edited by toad007; May 04, 2019 at 01:39 PM.
May 04, 2019, 01:43 PM
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Above 34k peak to 35k before the engine settled in.

Freight train mode in any direction plenty of thrust how much does that plane weigh?
May 04, 2019, 01:52 PM
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I dont count the peaks. That plane weighs 16oz full of fuel ready to fly, it hauls ass on my profi. I have not flown it with this engine yet. I will collect the rpm data when I do. I think for now I am going to save it for a Proto run in Oregon on Memorial day. I am hoping it will spin up a bit more at sea level.
Last edited by toad007; May 04, 2019 at 02:00 PM. Reason: added comment
May 04, 2019, 02:02 PM
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Time to build engine #2. I hope to repeat all this
May 06, 2019, 02:40 PM
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Here is a picture of my bench top. I straightened it up a lot for this. It needed it.
A picture of my obsessions..
May 06, 2019, 03:13 PM
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Toad, I’d be ashamed to have you in my house right now. I organized a build event for my club and the planes have to be done for tomorrow’s club meeting..

It looks like a JDAM fell on a model airplane factory in here!


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