160FX fuel flow rate and Max prop size ?
12-28-2004, 11:21 PM
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160FX fuel flow rate and Max prop size ?
I am presently looking at engine options for a 1/4 scale WW1 Albatros biplane from Jim Pepino plans and was seriously looking at the OS Max 160FX. The engine is fairly compact and has a low overall height in comparision to most other options for glow engines. The cowl area is cramped in the Albatross and the usual V-Twin options are way up there in price these days.
Would be running at 1/2 to 3/4 throttle most of the time.
1. What is the approximate fuel draw rate for the 160FX for 15% nitro glow fuel? Would like to size the fuel tank for a 10 > 12 minutes flight time.
2. As the engines rated HP is at 9000 RPM what might be the torque peak be in RPM?
3. Could I go to a 20 x 6 prop for a slow flying biplane without lugging the motor down too much? Trying to get to a prop that is more scale like.
Thanks kindly in advance
Bunsen
Would be running at 1/2 to 3/4 throttle most of the time.
1. What is the approximate fuel draw rate for the 160FX for 15% nitro glow fuel? Would like to size the fuel tank for a 10 > 12 minutes flight time.
2. As the engines rated HP is at 9000 RPM what might be the torque peak be in RPM?
3. Could I go to a 20 x 6 prop for a slow flying biplane without lugging the motor down too much? Trying to get to a prop that is more scale like.
Thanks kindly in advance
Bunsen
12-29-2004, 10:58 AM
#2
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RE: 160FX fuel flow rate and Max prop size ?
We've done no exact measuring of fuel consumption, but we can say that at full throttle you should get about 12-15 minutes of runtime on a 24-ounce tank.
O.S. has not released a torque curve for the 1.60 FX engine. Sorry.
A 20" propeller would be much too large. We normally prop the engine for low-to-mid-8.000's. Our tests ahve an 18 x 10 at 7,900 RPM and a 16 x 10 at 8,600. Run the engine in that RPM range and check different props to give you the desired flight characteristics. Use a scale-looking prop only if it will allow the engine to turn where it belongs and flies the model the way you want. When the engine's running, you can't see the prop, so why worry about what size it is if the model flies right? If you want a scale prop for display, then make an exact-scale display-only prop and mount it when the model's on display. That's what the scale competitors do.
O.S. has not released a torque curve for the 1.60 FX engine. Sorry.
A 20" propeller would be much too large. We normally prop the engine for low-to-mid-8.000's. Our tests ahve an 18 x 10 at 7,900 RPM and a 16 x 10 at 8,600. Run the engine in that RPM range and check different props to give you the desired flight characteristics. Use a scale-looking prop only if it will allow the engine to turn where it belongs and flies the model the way you want. When the engine's running, you can't see the prop, so why worry about what size it is if the model flies right? If you want a scale prop for display, then make an exact-scale display-only prop and mount it when the model's on display. That's what the scale competitors do.
06-14-2005, 10:27 AM
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RE: 160FX fuel flow rate and Max prop size ?
This engine is happy spinning a Mejzlik 20X6 prop at about 8200 rpm.
With a 17X8 APC and 5% nitro it will run full throttle 9200-9400 rpm for 5 minutes 20 seconds on 8 oz of fuel peaked. To fly it must be richened 200-300 rpm. With larger props the fuel consumption goes up.
With a 17X8 APC and 5% nitro it will run full throttle 9200-9400 rpm for 5 minutes 20 seconds on 8 oz of fuel peaked. To fly it must be richened 200-300 rpm. With larger props the fuel consumption goes up.
