Barnyard Buzzards

While all engines produce power the Propeller is essential to transmit this power.  A more efficient propeller will transmit more power to the air.  It would be fair to say that these recommended props are often much larger than those typically used in the USA but this helps significantly with noise reduction and therefore we will go with the larger prop.  The engines will not log down with these props, they just won’t quite develop all the power they could.  Though to be fair we do overpower anyway.  Prop sizes are only slightly above US recommendations.  If your field is noise sensitive (as many are) then head for one of the large props.  These figures are merely estimates – do not take them as gospel.  They are merely a rough guide to get you started.

Note: This Chart was Hijacked from the UK.  Please note the disclaimer above!!!

2 Stroke Glow Engines

Engine Size	Ideal Prop Size	Propeller Size Range	Ideal RPM Range
.10	7×4	7×4-6, 8×4	14000~16000
.15	8×4	7×5-6, 8×4-6	14000~16000
.25	9×5	9×4-6, 10×4-5	12000~15000
.32-.35	10×5	9×6-8, 10×5-6, 11×4-5	12000~15000
.40	11×5	10×6-8, 11×5-7, 12×5-6	11000~12000
.46	11×6	10×7-9, 11×6-8, 12×4.5-7	10000~12000
.53	11×7	10×8-10, 11×7-9, 12×6-8	10000~11000
.61	13×6	12×8-10, 13×6-7, 14×5-6	9500~11000
.75	13×7	12×9-11, 13×7-8, 14×6-7	9500~10500
.91 – 1.08	14×6	13×10-11, 14×6-8, 15×6-8	9000~10000
1.20 – 1.35	16×8	15×8-10, 16×8-10, 17×8	8500~9000
1.40 – 1.80	18×8	17×8-10, 18×8-10, 20×6-8	8000~9000
2.10	20×10	20×10, 22×8	8000~8500

Engine Size	Ideal Prop Size	Propeller Size Range	Ideal RPM Range
.26-.30	10×6	10×5-7, 11×4-5	10000~11000
.40-.45	11×6	11×6-7, 12×5-6	10000~11000
.48-.56	11×7	11×7-8, 12×6-7, 13×5-6	10000~11000
.63-.72	12×7	12×7-9, 13×6-7	10000~11000
.80 – .91	14×7	13×8-11, 14×7-9, 15×5-7	10000~11000
1.00 -1.20	14×8	14×7-8, 15×6-10, 16×6-8	9000~10000
1.40 – 1.50	16×8	16×8-12, 17×8-10, 18×6	8500~9500
1.80 – 2.00	17×8	16×10-12, 17×8-10, 18×8	8000-9500
2.40	20×8	18×10-12, 20×6-8	7500~8500
2.70	20×10	20×8-12, 21×8-10	7500~8500
3.00 -3.20	21×10	20×10-12, 21×8-10, 22×8	7500~8500

Engine Size	Ideal Prop Size	Propeller Size Range	Ideal RPM Range
9-10cc	13×7	12×8, 13×8	8500-9500
15cc	13×8	13×8-11, 15×8	9000~13000
23-30cc	16×8	16×8-10, 17×8-10, 18×8	8500~9500
40cc	20×8	18×10-12, 19×10, 20×8-10	6500~7800
45cc	20×10	20×10-12, 21×8-10, 22×8	6000~7500
50cc	21×10	20×12, 21×10-12, 22×8-10	6000~7500
60cc	22×10	22×10-12, 24×8-10, 26×8	6000, 6800
75cc	24×10	24×12, 26×10-12	6000~6500
100cc	26×10	26×10-12, 28×10	6000~6500
150cc	33×12	30×10-12, 32×10-12	5500~6000
200cc	34×11	32×12-14, 34×10-12, 36-10	5000~6000

2 Bladed	3 Bladed	4 Bladed
10×6	9×6	– – –
11×8	10×8	10×6
12×8	11×8	11×6
12×10	11×10	11×8
13×10	12×10	12×8
14×8	13×8	13×6
14×10	13×10	1`3×8
15×8	14×8	14×6
15×10	13×10	14×8
16×10	15×10	15×8
18×10	16×10	15×8
20×10	18×10	18×8
22×10	20×10	20×8