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Old Jan 27, 2013, 12:32 AM
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Joined Jan 2013
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Just bought one of these motors from Horizon, can't wait to get it in. Probably going to be waiting longer on the HobbyKing order that contains my LiFe batteries and BECs among other things but still, can at least get it mounted in the ARF and stare at it. Now to go put my glow engines up on the classifieds.
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Old Jan 27, 2013, 08:44 AM
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Norway
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I bought one of these from Sussex model center in GB. Have it on a phoenixmodel future http://www.phoenixmodel.com/Default....&CatId=5&id=22

testing on ground give me 12450rpm with apc 12x4 Tried it in the air today and it was plenty of power. had 2 deadstick becouse of the pressure tube fell off the niple on the muffler. have to use some strips to fasten it. changed to apc 12x8 today and got 9300rpm. I have only 3 tanks of gas tru it yet. So i think this is a great little engine. HAve little video her from testing on the ground with the 12x4 prop

http://www.youtube.com/watch?v=Be0FC...TQldoQpiBrF5MQ
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Old Jan 27, 2013, 11:22 AM
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Israel, Ramat HaSharon
Joined Nov 2003
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Tyor,


That nice number on the APC 12x4 is 1.1 HP calculated output.

The 9,300 RPM on the 12x8 is a lower .86 HP... I believe this size is overloading this engine.
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Old Jan 27, 2013, 11:33 AM
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Quote:
Originally Posted by DarZeelon View Post
Tyor,


That nice number on the APC 12x4 is 1.1 HP calculated output.

The 9,300 RPM on the 12x8 is a lower .86 HP... I believe this size is overloading this engine.
DAR,

Can you post the formula on how to figure the HP? Also does the formula work with three bladed props as well as two blade? I would like to be able to find the optimum prop for my B-25J. Right now I am breaking in the engines on the TH Uproar and have graduated to the 11-7 3 blade. This is the first engine and I will repeat the process for the other one.
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Old Jan 27, 2013, 11:36 AM
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I have to fine tune it, and it is almost new. have to run it a bit more before i can say some more. But I like te engine so far
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Old Jan 27, 2013, 11:58 AM
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Rjstrickjr,


It is not a formula, it's an application.
I sent you a PM.

Tyor, I sent it to you too by error.
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Old Jan 27, 2013, 12:47 PM
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pm sendt
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Old Jan 27, 2013, 04:07 PM
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USA, MS, Oxford
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Hi all!
In Post 390, Hance shows his engine mounted in a profile plane.
What model and vendor?
Thanks!
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Old Jan 27, 2013, 05:20 PM
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USA, ID, Niter
Joined Jul 2008
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Quote:
Originally Posted by jansenoxford View Post
Hi all!
In Post 390, Hance shows his engine mounted in a profile plane.
What model and vendor?
Thanks!
I don't want to side track this thread. The plane is a Sabre 47 from Value Hobby. If you want more details about the plane the good, not so good and stuff that really sucked shoot me a PM. http://www.valuehobby.com/airplanes/...dy-to-fly.html
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Old Jan 27, 2013, 06:53 PM
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Havw a quick question, would a LiFe 1100 mah 2S battery be good to operate this in a 7 servo trainer for multiple flights on a BEC or should I run two packs?
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Old Jan 28, 2013, 12:15 AM
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Joined Dec 2012
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Quote:
Originally Posted by tyor View Post
testing on ground give me 12450rpm with apc 12x4 Tried it in the air today and it was plenty of power. had 2 deadstick becouse of the pressure tube fell off the niple on the muffler. have to use some strips to fasten it. changed to apc 12x8 today and got 9300rpm. I have only 3 tanks of gas tru it yet. So i think this is a great little engine. HAve little video her from testing on the ground with the 12x4 prop
Tyor,

Although Dars numbers may be correct, I don't agree with his conclusion. The horsepower calculation may be down from 1.1HP, but that doesn't mean that you shouldn't run that prop. It may be "over propping" the engine but that simply means the engine is not running at the peak HP RPM. And at a certain point you can cause damage to an engine by running too large of a prop, you have not reached that point. If the 12x8 prop is a good match for your airplane and flying style, then it is a great prop choice.

Jimmy.
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Old Jan 28, 2013, 04:20 AM
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Originally Posted by jspauld2 View Post
Tyor,

Although Dar's numbers may be correct, I don't agree with his conclusion. The horsepower calculation may be down from 1.1 HP, but that doesn't mean that you shouldn't run that prop. It may be "over propping" the engine but that simply means the engine is not running at the peak HP RPM. And at a certain point you can cause damage to an engine by running too large of a prop, you have not reached that point. If the 12x8 prop is a good match for your airplane and flying style, then it is a great prop choice.

Jimmy.

Jimmy,


The drop in RPM from 12,450 to 9,300 is 24.3%.
The drop in output from 1.1 HP to .86 HP is 21.8%.

So, the torque this engine produces is greater on the heavier propeller, than it is on the lighter one.
Over-propping can be defined as using a prop so large, that it loads the engine to below its RPM of maximum torque.
At least as far as glow engines are concerned; over-propping beyond this limit could cause overheating; and unloading in flight will be greater than normally foreseen, possibly causing the engine to lean-out excessively.
One should not over-prop, even if a prop seems to be the most appropriate size for the engine + plane combo.

Since neither of us know what this RPM of maximum torque is, perhaps I was a bit 'quick on the trigger', so to speak, to call this larger propeller an over-propping.
The RPM drop just seemed to me rather large at first sight...

Also, Dave Dunn in the other forum, quoted his OS.61SF engine, at 11,010 on the 12x8 prop size with the normal muffler.
This equates to 1.43 HP and this 'Long Stroke' engine surely gets its maximum torque down low...


I suppose these 10GX engines are uniform enough in production (all parts CNC manufacturing accuracy), so all are within no more than 100 RPM of each other on the same prop, after a properly done break-in.

If other participants of this thread, or yourself Jimmy, could tach this engine (in ground static conditions, of course...) with a greater selection of large props, I would easily be able to calculate the RPM, at which peak torque occurs.
As an immediate outcome, we will all know what the largest usable prop would be for this engine.

Glow engines of this displacement range, generally produce their maximum torque somewhere between 7K and 10K RPM. Each engine has its main torque peak somewhere within this range.



One more critical issue, Jimmy; The PropPower does not have a prop factor for your Evolution propellers.
I do not know which manufacturer manufactures them for you; and without this number I cannot calculate.

If you could tell me which make they are identical to, or just provide their prop factor, it would be very helpful.

Otherwise, please provide RPM numbers with more commonly available props (APC, MA G/F3, Etc.).
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Last edited by DarZeelon; Jan 28, 2013 at 06:04 AM. Reason: Corrections.
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Old Jan 28, 2013, 10:23 AM
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Norway
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had the engine running again today. Tuned a little an got 9500rpm with apc12x8, It is running better and better. Nice idle at 1850rpm.
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Old Jan 28, 2013, 11:20 AM
Horizon Hobby Employee
Joined Dec 2012
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Quote:
Originally Posted by DarZeelon View Post

Jimmy,


The drop in RPM from 12,450 to 9,300 is 24.3%.
The drop in output from 1.1 HP to .86 HP is 21.8%.

So, the torque this engine produces is greater on the heavier propeller, than it is on the lighter one.
Over-propping can be defined as using a prop so large, that it loads the engine to below its RPM of maximum torque.
At least as far as glow engines are concerned; over-propping beyond this limit could cause overheating; and unloading in flight will be greater than normally foreseen, possibly causing the engine to lean-out excessively.
One should not over-prop, even if a prop seems to be the most appropriate size for the engine + plane combo.

Since neither of us know what this RPM of maximum torque is, perhaps I was a bit 'quick on the trigger', so to speak, to call this larger propeller an over-propping.
The RPM drop just seemed to me rather large at first sight...

Also, Dave Dunn in the other forum, quoted his OS.61SF engine, at 11,010 on the 12x8 prop size with the normal muffler.
This equates to 1.43 HP and this 'Long Stroke' engine surely gets its maximum torque down low...


I suppose these 10GX engines are uniform enough in production (all parts CNC manufacturing accuracy), so all are within no more than 100 RPM of each other on the same prop, after a properly done break-in.

If other participants of this thread, or yourself Jimmy, could tach this engine (in ground static conditions, of course...) with a greater selection of large props, I would easily be able to calculate the RPM, at which peak torque occurs.
As an immediate outcome, we will all know what the largest usable prop would be for this engine.

Glow engines of this displacement range, generally produce their maximum torque somewhere between 7K and 10K RPM. Each engine has its main torque peak somewhere within this range.



One more critical issue, Jimmy; The PropPower does not have a prop factor for your Evolution propellers.
I do not know which manufacturer manufactures them for you; and without this number I cannot calculate.

If you could tell me which make they are identical to, or just provide their prop factor, it would be very helpful.

Otherwise, please provide RPM numbers with more commonly available props (APC, MA G/F3, Etc.).
Dar,

I see what you mean. The point I am making is this. You may technically be using a prop that brings the engine below the maximum torque RPM, but we have done extensive testing to ensure that the engine experiences no overheating or unwinding issues.

As far as the Evolution prop constant, we estimate the prop constant to be somewhere between 1.23 and 1.3. It is slightly heavier loaded than the APCs.

Jimmy
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Old Jan 31, 2013, 09:16 PM
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United States, TX, Lewisville
Joined Jan 2011
71 Posts
Has anybody tried this engine for 3d? I'm trying to see what kind of plane I want to build and I would prefer gas over nitro
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