Cobra C4120/22 Motor Propeller Data
Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (6S)
22-Turn Delta 430 RPM/Volt Io = 1.14 Amps @ 20v Rm = 0.040 Ohms 45 Amps 1000 W 
 
Outside Diameter Body Length Total Shaft Length Shaft Diameter Motor Weight
49.8 mm,  1.96 in. 51.8 mm,  2.04 in. 74.5 mm,  2.93 in. 6.00 mm,  0.236 in. 290 gm,   10.23 oz
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 14x12-E 14.8 25.09 371.3 5,294 60.2 1492 52.63 4.02
APC 15x8-E 14.8 17.67 261.6 5,590 42.3 1884 66.46 7.20
APC 15x10-E 14.8 24.35 360.4 5,323 50.4 2130 75.13 5.91
APC 16x8-E 14.8 25.86 382.7 5,260 39.8 2473 87.23 6.46
APC 16x10-E 14.8 28.83 426.7 5,149 48.8 2508 88.47 5.88
APC 16x12-E 14.8 36.16 535.2 4,890 55.6 2081 73.40 3.89
APC 17x8-E 14.8 28.63 423.7 5,148 39.0 2736 96.51 6.46
APC 17x10-E 14.8 34.32 508.0 4,955 46.9 2802 98.84 5.52
APC 17x12-E 14.8 39.37 582.6 4,763 54.1 2614 92.21 4.49
APC 18x8-E 14.8 30.27 448.0 5,102 38.7 3065 108.11 6.84
APC 18x10-E 14.8 35.24 521.5 4,916 46.6 3209 113.19 6.15
APC 19x8-E 14.8 39.52 584.9 4,752 36.0 3550 125.22 6.07
APC 19x10-E 14.8 39.59 585.9 4,746 44.9 3559 125.54 6.07
APC 19x12-E 14.8 45.02 666.3 4,534 51.5 3641 128.43 5.46
APC 20x8-E 14.8 41.94 620.7 4,650 35.2 3872 136.58 6.24
MAS 14x7x3 14.8 19.03 281.6 5,531 36.7 1930 68.08 6.85
MAS 14x9x3 14.8 22.84 338.0 5,383 45.9 2184 77.04 6.46
MAS 15x7x3 14.8 23.88 353.4 5,335 35.4 2357 83.14 6.67
MAS 16x8x3 14.8 27.34 404.6 5,204 39.4 2630 92.77 6.50
MAS 16x10x3 14.8 34.83 515.4 4,936 46.7 3071 108.33 5.96
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 12x10-E 18.5 19.66 363.7 6,983 66.1 1645 58.03 4.52
APC 12x12-E 18.5 23.46 434.0 6,822 77.5 1506 53.12 3.47
APC 13x8-E 18.5 19.76 365.5 6,979 52.9 2038 71.89 5.58
APC 13x10-E 18.5 27.20 503.1 6,670 63.2 1935 68.25 3.85
APC 14x7-E 18.5 22.78 421.4 6,849 45.4 2425 85.54 5.76
APC 14x8.5-E 18.5 24.36 450.6 6,788 54.6 2536 89.45 5.63
APC 14x10-E 18.5 24.20 447.6 6,790 64.3 2466 86.98 5.51
APC 14x12-E 18.5 36.48 674.9 6,302 71.6 2121 74.82 3.14
APC 15x6-E 18.5 24.09 445.6 6,797 38.6 2755 97.18 6.18
APC 15x8-E 18.5 25.76 476.5 6,723 50.9 2773 97.81 5.82
APC 15x10-E 18.5 36.35 672.4 6,303 59.7 2999 105.79 4.46
APC 16x8-E 18.5 38.87 719.0 6,202 47.0 3584 126.42 4.98
APC 16x10-E 18.5 42.65 789.1 6,055 57.3 3570 125.93 4.52
APC 17x8-E 18.5 42.10 778.8 6,073 46.0 3905 137.74 5.01
APC 17x10-E 18.5 49.55 916.6 5,746 54.4 3821 134.78 4.17
APC 18x8-E 18.5 42.89 793.5 6,013 45.6 4339 153.05 5.47
MAS 12x8x3 18.5 20.19 373.5 6,859 52.0 2134 75.27 5.71
MAS 13x8x3 18.5 23.15 428.3 6,835 51.8 2413 85.12 5.63
MAS 14x7x3 18.5 27.22 503.6 6,673 44.2 2854 100.67 5.67
MAS 14x9x3 18.5 32.52 601.7 6,454 55.0 3208 113.16 5.33
MAS 15x7x3 18.5 33.81 625.4 6,392 42.4 3412 120.35 5.46
MAS 16x8x3 18.5 38.73 716.4 6,191 46.9 3828 135.03 5.34
MAS 16x10x3 18.5 48.47 896.6 5,795 54.9 4265 150.44 4.76
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 11x8.5-E 22.2 18.33 406.9 8,376 67.4 1785 62.96 4.39
APC 11x10-E 22.2 22.63 502.4 8,302 78.6 1685 59.44 3.35
APC 12x6-E 22.2 17.81 395.3 8,521 48.4 2181 76.93 5.52
APC 12x8-E 22.2 22.64 502.5 8,303 62.9 2019 71.22 4.02
APC 12x10-E 22.2 27.79 617.0 8,081 76.5 2203 77.71 3.57
APC 12x12-E 22.2 30.25 671.5 7,841 89.1 2014 71.04 3.00
APC 13x6.5-E 22.2 25.35 562.8 8,181 50.4 2785 98.24 4.95
APC 13x8-E 22.2 27.61 612.9 8,088 61.3 2746 96.86 4.48
APC 13x10-E 22.2 37.76 838.2 7,664 72.6 2600 91.71 3.10
APC 14x7-E 22.2 31.20 692.6 7,806 51.7 3235 114.11 4.67
APC 14x8.5-E 22.2 33.36 740.5 7,837 63.1 3450 121.69 4.66
APC 14x10-E 22.2 33.44 742.3 7,848 74.3 3283 115.80 4.42
APC 14x12-E 22.2 49.19 1091.9 7,179 81.6 2777 97.95 2.54
APC 15x4-E 22.2 25.09 557.0 8,191 31.0 3272 115.42 5.87
APC 15x6-E 22.2 33.55 744.8 7,827 44.5 3807 134.29 5.11
APC 15x8-E 22.2 35.19 781.2 7,760 58.8 3736 131.78 4.78
APC 15x10-E 22.2 51.08 1133.9 7,096 67.2 3842 135.52 3.39
MAS 12x6x3 22.2 19.33 429.0 8,444 48.0 2302 81.20 5.37
MAS 12x8x3 22.2 26.99 599.2 7,987 60.5 2922 103.07 4.88
MAS 13x8x3 22.2 29.97 665.4 7,863 59.6 3225 113.76 4.85
MAS 14x7x3 22.2 36.19 803.4 7,722 51.2 3883 136.97 4.83
MAS 14x9x3 22.2 42.93 953.1 7,442 63.4 4255 150.09 4.46
MAS 15x7x3 22.2 44.71 992.5 7,335 48.6 4541 160.18 4.58
MAS 16x8x3 22.2 50.93 1130.6 7,063 53.5 5051 178.17 4.47
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 10x7-E 29.6 20.32 601.5 11,276 74.7 2144 75.63 3.56
APC 10x10-E 29.6 29.79 881.8 10,682 101.2 2010 70.90 2.28
APC 11x5.5-E 29.6 22.65 670.4 11,168 58.2 2887 101.83 4.31
APC 11x7-E 29.6 27.39 810.6 10,956 72.6 3037 107.13 3.75
APC 11x8.5-E 29.6 33.00 976.9 10,681 86.0 2929 103.32 3.00
APC 11x10-E 29.6 37.71 1116.3 10,473 99.2 2724 96.09 2.44
APC 12x6-E 29.6 30.42 900.5 10,651 60.5 3602 127.06 4.00
APC 12x8-E 29.6 38.26 1132.4 10,443 79.1 3318 117.04 2.93
APC 13x6.5-E 29.6 45.50 1346.8 10,129 62.3 4340 153.09 3.22
APC 15x4-E 29.6 42.96 1271.6 10,072 38.2 5369 189.38 4.22
MAS 10x7x3 29.6 22.28 659.6 11,189 74.2 2735 96.47 4.15
MAS 11x7x3 29.6 27.36 809.8 10,938 72.5 3281 115.73 4.05
MAS 11x8x3 29.6 30.30 896.7 10,812 81.9 3393 119.68 3.78
MAS 12x6x3 29.6 31.18 922.9 10,767 61.2 3834 135.24 4.15
MAS 12x8x3 29.6 43.07 1274.8 10,097 76.5 4699 165.75 3.69
MAS 13x8x3 29.6 48.96 1449.1 9,956 75.4 5250 185.19 3.62
Propeller Chart Color Code Explanation
   The prop is to small to get good performance from the motor. (Less than 50% power)
   The prop is sized right to get good power from the motor. (50 to 80% power)
   The prop can be used, but full throttle should be kept to short bursts. (80 to 100% power)
   The prop is too big for the motor and should not be used. (Over 100% power)
PLEASE NOTE: 
The data contained in this prop chart is based on actual measurements taken in a controlled test 
environment.  The test voltages used are based on a properly sized Li-Po battery for the current
draw of the motor being tested.  If you are using a larger than normal capacity battery, or a very
high C-Rated battery, your actual voltages will be higher than those shown in this chart, and this
will result in higer current draw for each prop used.  You should always test your power system
with a watt meter whenever a prop is used to ensure that you are not exceeding the recommended
rating of the motor being used.  The prop recommendations in this chart are based on the motor
receiving adequate cooling throughout its operation.  If your motor is being used inside a cowl, you
must provide adequate cooling to the motor and make sure that the motor is not getting too hot
during operation.