18
30% Ultimate ARF
Epoxy the firewall in place making
sure to keep it square with the sides.
Add the triangle top supports on
both sides and the tri stock on the
back side. Drill 1/8” holes 1” deep in
five places on each side of the motor
box and pin the firewall using 1/8”
dowels and glue.
dowels four
places each
side
You will probably need to notch the
firewall to clear the cylinder head.
If you plan to use a Pitts style muf-
fler you will have to notch the bot-
tom of the firewall. Just cut the fire-
wall and motor box sides to accept
the muffler and then box the area
back in with 1/8” plywood with tri
stock on the inside.
Attach the motor box top covers
using the 10 #4x1/2” screws and #4
washers.
You can cut a hole in the motor box
side to pass the spark plug lead and
fuel line through to the engine.
