9
Place an “
×
” to ensure task completion:
What you will need in this chapter:
Firewall and Fuse
Nine1/8 inch dowels cut to ½ inch lengths
Triangle stock included with the kit
Not Provided:
30 to 45 minute epoxy
An engine in the recommend size range
3 ½ inch spinner
Propeller
A drill and drill bits
Center punch
A 12” square or incidence meter
½ inch low tack masking tape for DA-50
White wood glue such as Elmer’s for BME 50
Note: Our measurements for setting the right thrust are just a guide and will get you in the ballpark. Since
the distance from the firewall to the spinners back plate can very with type and installation, we recommend
using your own calculations.
Also with the engine is installed, you will want 6 ½ to 7 inches from the firewall to the spinner back plate for
proper cowl placement.
BME 50 and DA-50 installation
First, we’ll find and mark the vertical centerline on the firewall. Take the firewall and measure it from
side to side to find the center and draw a vertical line using your square.
Draw another line parallel approximately 5mm to the right of the vertical centerline. This gives us our
offset centerline for 3 degrees of right thrust.
Using your square, make sure the right side of the motor box matches the left side. If not, use the square
to as a guide for the next measurement.
Now measure and draw a vertical line down the inside of the right hand side of the motor box back
0.5cm (5mm). This establishes our 3 degrees of right thrust built in to the firewall. Re-check your
measurement to ensure its square and test fit the firewall.
Mount the firewall with the front of the firewall flush
on the left and at your marked 5mm line on the right
using at least 30-minute epoxy. Make sure it’s square
up and down to ensure you have not created any up or
down thrust. Also ensure your thrust line matches the
lines on the outside of the motor box. Use a few
clamps to hold the firewall in place until the epoxy has
cured.
Epoxy the 3 pieces of triangle stock in place on the
inside between the motor box and firewall to re-enforce
the firewall. Epoxy the one additional triangle stock in
place in front of the firewall on the right side for added
strength.
