Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

Magnun Maiden, Wow

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Old 07-05-2003, 03:01 AM
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Mattyb
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Default Magnun Maiden, Wow

well it flies!!!!
ended up with a 8x7.5 bolly prop. It was as close to 8x8 as i could get but have some on order now.

Well if anyone wants a plane to use as practice before getting into jets this is the one.

Was getting 17500 rpm with that prop and the header standard.
But gee it whistled by nicely.

Just needed to get that out of my system, cant wait till tomorrow.

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Old 07-05-2003, 11:22 PM
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Default Magnun Maiden, Wow

Good to hear the first flight on the Mag turned out to be a succes.

On a prop that small you can cut at least 1 inch straight off that header... you will have problems with your pipe coupler when you do that, but who cares (actually you could cut 3/4" off the header and 1/4" off the pipe, same effect no problems )

Your engine is barely revving at 17.5K... you need AT LEAST 2K more... make that 3K with the 8x7.5...

So you had fun today? Just wait until your engine is broken in, pipe is set correctly and you become a little more comfortable with the plane... then talk about fun
If you don't smell the exhaust on a low fly-by you're not flying low/close enough...
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Old 07-06-2003, 06:14 AM
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Default Magnun Maiden, Wow

thanks rudeboy.
More flights today and the knees are knocking more and more.
Im only using that prop for the moment and have a couple of apc 8x8 props coming, then will see how she goes.

How much do you take off wthe header with an 8x8?

she is unloading more and more as she brakes in.

Still got the smile on my face
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Old 07-06-2003, 12:44 PM
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Default Magnun Maiden, Wow

I had to take almost 20mm off the header to get it on its sweet spot. I had it set another 2mm shorter at a certain moment, but with the pipe that short the engine overheated in a matter of seconds... so I backed it off a couple of millimeters and then it ran fine.

But don't follow these figures blindly. I also lowered the compression of the engine, so it's possible I have my pipe set too short for a standard compression engine. It also depends on the altitude you fly at, the fuel you use, ....

You've got to work this out for yourself. All I can say is that it will rev up considerably when you set the pipe to the correct length... (20mm shorter is A LOT on an engine like this)
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