EX-TIMING AERO 40\51\61\65 AERO 75 & 85 OPS/OS/ST OPS/OS/YS OS/YS
RPM 130degree 135degree 133 degrees 140degree 145degree 150degree 155degree
9000 18 1/2 18.5-18.75 18.3-18.7 19 5/8 20 1/4 20 7/8 21 1/2
9500 17 3/4 17 3/4 -18 17.1.4-17.9 19 19 5/8 20 3/8 21
10000 17 5/16 17.5-17.25 17.25-17.5 18 3/8 19 19 3/4 20 1/2
10500 16 3/4 17-17.25 16.9- 17.2 17 7/8 18 5/16 19 19 7/8
11000 16 5/16 17-16.75 16.7 17 17 5/16 17 7/8 18 5/8 19 1/4
11500 16 16 5/16 16 3/4 17 3/8 17 3/4 18 3/4
12000 15 3/4 16 1/8 16 3/8 16 3/4 17 1/2 18 1/8
12500 15 3/8 15 3/4 16 1/16 16 3/8 17 17 5/8
13000 14 7/8 15 3/8 15 9/16 16 16 1/2 17 1/8
13500
PIPE TUNING CHART by Randy Smith
MEASURE taken from the GLO- PLUG to FIRST BAFFLE
FOR THE P.A. 40 - 61 ENGINES
A Good PIPE Starting Point 16 3\4to 17.5 inches PROPS 11,5 FOR THE 40,12 FOR THE 51
12.5 to 13 INCHES FOR THE 61 3.8 TO 4 PITCH 10,500-11,200 RPMs For the 61 @ 3.8 PITCH 10,500 -11,200 RPM
IF IT IS TOO HOT OR COMES ON TOO STRONG MOVE OUT toward 17.5 INCHES
IF PLANE SPEEDS UP DURING ( normally the back half)THE FLIGHT MOVE PIPE OUT ,
IF PLANE SLOWS DOWN DURING (normally the back half of the flight)FLIGHT MOVE PIPE IN SHORTER Make sure the fuel tank is good and not causing any slow down or speed up problems before moving pipe
best props pipe combo lenghts
40 bolly 11.75 x 4.25 cut to 11.3-11.5 inches pipe 16.75
51 bolly 12 x 4.25 3 blade as is bolly 12.2 x 4.2 2 b;ade as is pipe 17 in to 17.25
61 12x 4.25 3 blade 13 x 4.5 3 blade cut to 12.5 or 13 x 4.5 2 blade as is pipe 17 to 17.5
65 bolly 13 x 4.5 3 blade or 13.75 x 4.5 3 blade pipe 17 to 17.5
75 bolly 15 x 4.7 2 blade ,13 3\4 and 14 inch 3 blades 4to 4 3\4 pitch Bolly 14 to15x 4.5 2 blade pipe 17.25 to 17.75
This is a tuning-timing chart for Several engines
I will write more when I get a little time
Randy