Brief Description: Determine size and design of boot cowl outlet
Been trying to figure size and configuration of engine cowl outlet. Here is my approach to arriving at an opening size. The Bearhawk manual suggest 125 - 150% of inlet size.
Bob Barrow's nosebowl inlets:
5" x 7.5" x 2 each = 75 sq in
Given it is New Mexico and hot, going to 150%. 75 sq in (inlets) x 150% = 112.5 sq inches Target
Allowance for exhaust pipe and other obstructions - 2 pipes with 3" x 3" = 18 sq in
112.5 sq in target plus 18 sq in obstruction allowance = 130 sq in cross sectional open
130 sq in opening divided by 20 in tunnel width = 6.5" cross sectional opening.
Cut lower engine cowl for 6.5" opening to top edge of tunnel. Note this 6.5" is on diagonal.
Since rolling and flaring of airbox opening worked so well decided to do same here.
