Hi All,

Can anyone suggest a good easy formula to figure engine offset vs side or down thrust so that the propeller shaft will be centered in cowl opening.

Thanks in advance for your knowledge.

The engine offset concept and the angled thrust are of two different ideas. The offset engine will not set the center of thrust on the centerline of the fuselage, for that is why it is referred to an an offset. It is not too often used today, but twenty years ago, the numbers were about 1/8" to 1/4" offset of crankshaft to the left of centerline for the fuselage.

The angled thrust is different, and can be used in combination with offset also. But it is most often today a 1 to 3 degree tilt to the right on single engine A/C.

You may want to move this question over to the aero section, for it has been mentioned there about 2-4 times each year.

Wm.

One way is to use trigonometry. If the distance from the back of the engine drive washer to the back of the motor mount is 4'', and the offset angle is 2 degrees, Sin (2d)=(offset distance)/4'', or offset distance=4''*sin(2d)

Another way is to do it graphicaly like the illustration below.

>>Optomist; Glass half full -Pessamist; Glass half empty
>>Engineer; Glass too big

A realist knows if they stick around long enough there gonna have to wash the glass

Try this: http://www.lcrcc.net/offset_calc.htm

The covering weight chart was very useful, as was the thrust calculator . For engine offset, it's pretty simple math. I am a big advocate of education. I believe that everyone except the learning disabled should know algebra and trig by the time they leave high school. Tip speed? v=rw (w-omega or rotational speed, r-radius). High school physics.

Thanks for the help everybody.