OS 56 Alpha FS - RPM readings
#1
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I've just broken in my 56 alpha a week ago with 10% Nitro CoolPower fuel using 11x7 MA 3-blade prop.
Initial rpm readings during 3rd tank just before first flight is 11500 RPM peak.
I suspect its going to get a *little* higher after the first gallon as this engine really likes to rev. (lightning fast transitions from idle to max rpm).
If the weather permits, tomorrow I will try it with APC 12x6 and APC 13x6 props and report back.
So far I cannot believe how *smooth* and *CLEAN* this engine is running..
If there are others who have some rpm readings for this baby please chime in.
Initial rpm readings during 3rd tank just before first flight is 11500 RPM peak.
I suspect its going to get a *little* higher after the first gallon as this engine really likes to rev. (lightning fast transitions from idle to max rpm).
If the weather permits, tomorrow I will try it with APC 12x6 and APC 13x6 props and report back.
So far I cannot believe how *smooth* and *CLEAN* this engine is running..
If there are others who have some rpm readings for this baby please chime in.
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ORIGINAL: TimC
I'm looking forward to the readings with the 12x6 APC. Your new O.S. sounds pretty strong on the top end.
I'm looking forward to the readings with the 12x6 APC. Your new O.S. sounds pretty strong on the top end.
Did you ever try the 12x6 APC?
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I jut got mine delivered today.
I have props in 11x7-8, 12x6-8, 12.5x6 & 13x6-9, mostly APC's with a few bollys and MA's
I'm planning on breaking the motor in this coming weekend and testing the 12" props. I'm hoping the 12x7 or 8 give me the performance i'm looking for on a little pattern plane.
I have props in 11x7-8, 12x6-8, 12.5x6 & 13x6-9, mostly APC's with a few bollys and MA's
I'm planning on breaking the motor in this coming weekend and testing the 12" props. I'm hoping the 12x7 or 8 give me the performance i'm looking for on a little pattern plane.
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I broke my motor in today and recorded the following figures.
All are on 20/20 Fuel after about 10oz if the rich-lean-rich-lean break in cycle suggested in the manual.
APC 12x6 10,900
APC 12x7 10,300
APC 12x8 9,600
APC 13x6 10,000
APC 14x5 narrow 10,000
Out of the box i couldn't get a reliable idle below 3,000 but after about 30ozs of fuel i leaned the low need 1/8th of a turn and it idled around 2,100 with great transition.
All are on 20/20 Fuel after about 10oz if the rich-lean-rich-lean break in cycle suggested in the manual.
APC 12x6 10,900
APC 12x7 10,300
APC 12x8 9,600
APC 13x6 10,000
APC 14x5 narrow 10,000
Out of the box i couldn't get a reliable idle below 3,000 but after about 30ozs of fuel i leaned the low need 1/8th of a turn and it idled around 2,100 with great transition.
#9
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We had a club fun fly this weekend just gone so i mounted my .56 onto a ModelTech Magic and put a 13x4 APC prop on it.
I tached it a 11,200 peaked and and flew it at 10,900.
There were 10 other Magics at the fun fly and the other 9 were all .46 2-strokes. The .56 had enough power to beat most of 46's on the vertical climb. It just went straight up and was almost a dot at the 10 second cut off.
Such a sweet little motor.
I tached it a 11,200 peaked and and flew it at 10,900.
There were 10 other Magics at the fun fly and the other 9 were all .46 2-strokes. The .56 had enough power to beat most of 46's on the vertical climb. It just went straight up and was almost a dot at the 10 second cut off.
Such a sweet little motor.
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The Magic is a funny bird some props the run up nice on the ground don't do so hot in the air
I found the 13x4 works best with the magnun 52 4 stroke I have a os56 that I'm going to use was hoping the 13x6 would work for better vertical and hover power
I found the 13x4 works best with the magnun 52 4 stroke I have a os56 that I'm going to use was hoping the 13x6 would work for better vertical and hover power
#13

Omega 15% - half the lube is castor. I have run just a half a gallon and I can tell the idle is getting better. It does have a narrow range of needle adjustment. It needs to be needled fairly close to lean on the high speed to have a mid range that's workable without being rich. The low speed had to be leaned about a 1/3 turn. I do have the baffle in the muffler. Runs too nice to fuss with, very economical on fuel and leaves a small mess to deal with.
#14
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Removing the baffle wont really increase performance much, wont affect the needle settings or the way it runs but the sound is much better IMO.
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I live in Vegas not sure of the alt and did test today at about 90 degrees
15% Cool Power around 1/2 gallon through motor in the last two weekends. 1.5-2 hrs total time on engine. Just started timing this weekend. 50 mins today.
13x6 apc sport
10,100 RPM operating RPM
Idle is about 2800 right now had to tweek the low end needle.
15% Cool Power around 1/2 gallon through motor in the last two weekends. 1.5-2 hrs total time on engine. Just started timing this weekend. 50 mins today.
13x6 apc sport
10,100 RPM operating RPM
Idle is about 2800 right now had to tweek the low end needle.
#17
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Does anyone have tested this engine with a Graupner 12,5x6? I'm curious to compare it to my TT F-75s...because it looks that this engine gives more power than mine, I'm getting about 9600 RPM....but the Graupner according to Pe's spreadsheet, has a greater prop constant...
Saludos,
Jorge
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Yes, runs the 12.5-6 very well, can't give RPM's , but runs very good with nice verticals and that is not on a 3D airplane.
L.
L.
#21
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Yes...absolutely....I run my TT F75s about at 9650 RPM with a Graupner 12.5x6....
And accordign to that, the 56 alpha is a way much better than many 70 4 stroke engines including magnums, and the engines around the same displacement...
I'm really impressed that a 56 can turn a 13x6 so good.
@Cherokee flyer.
Can you tach your engine?,.... that runs very good and etc...does say that it is a good engine, but doesn't tell much about power and doesn't work to comapre engines...because the flight performance you get is with the combo engine, plane you have...
Mine runs very good, no flame outs, do a great job on my plane...but...
Saludos,
Jorge
And accordign to that, the 56 alpha is a way much better than many 70 4 stroke engines including magnums, and the engines around the same displacement...
I'm really impressed that a 56 can turn a 13x6 so good.
@Cherokee flyer.
Can you tach your engine?,.... that runs very good and etc...does say that it is a good engine, but doesn't tell much about power and doesn't work to comapre engines...because the flight performance you get is with the combo engine, plane you have...
Mine runs very good, no flame outs, do a great job on my plane...but...
Saludos,
Jorge
#23

I ran my new 56 Alpha in a boat last summer testing on the water for the first season.
Nothing this year yet will wait till the heat of the summer settles down. The engine
has about 16 runs thus far. The engine seems to handle the rpm just fine.
16,069 rpm in the hand at launch / incoming 13,242 rpm loaded in the last pass
12,918 rpm in the sound shift average 13,080 rpm radar 44 mph not bad for
a four stroke looking to hit 60 mph this year with new props to try.
Nothing this year yet will wait till the heat of the summer settles down. The engine
has about 16 runs thus far. The engine seems to handle the rpm just fine.
16,069 rpm in the hand at launch / incoming 13,242 rpm loaded in the last pass
12,918 rpm in the sound shift average 13,080 rpm radar 44 mph not bad for
a four stroke looking to hit 60 mph this year with new props to try.