spreader bar from each mount half. The surfaces where the
spreader bars were attached must be smooth to allow the
mount halves to fit together. Trim the flashing off any rough
edges if necessary.
❏
2. Copy the
engine mount template
from the back page
and tape it to the firewall as shown. At the locations on the
template, drill four 7/32" [5.5mm] holes in the firewall for the
engine mount blind nuts.
❏
3. Install four
8-32 blind nuts
to the inside of the firewall.
Pull the blind nuts into the back side of the firewall using
8-32 socket head cap screws with a flat washer under the
head of each screw. Fit the two halves of the Engine Mount
together. Use four
#8 flat washers
and four
8-32 x 1"
socket head cap screws
to secure the engine mount to the
firewall. Do not tighten the screws at this time, as the mount
must be adjusted for the engine.
❏
4. Test fit your engine into the mount. Adjust the width of
the rails to fit the engine snugly. Tighten the mount screws
to allow marking the engine mounting holes without moving
the rails.
❏
5. Position the engine on the engine mount rails so the
propeller thrust washer is 5-3/4" [136mm] ahead of the
firewall. Use a Great Planes Dead Center Hole Locator
(GPMR8130) (not included) or a sharpened piece of wire to
scribe the four engine mount holes onto the rails. Use a
center punch at the marks to prevent the drill bit from
wandering, then drill #29 pilot holes through the rails. Be
sure to hold the drill perpendicular to the rails. If you have
access to a drill press, this is a good tool for this purpose.
Use an 8-32 tap to tap the holes for the 8-32 screws. Use
four 8-32 x 1" socket head cap screws to secure the engine
to the mount.
❏
6. Drill a 3/16" [5mm] hole in the firewall for the throttle
pushrod. The hole location will depend on whether you are
installing a 2-stroke or 4-stroke engine.
❏
7. Roughen the outside surface of the 36" [910mm]
throttle pushrod tube
with coarse grit sandpaper. Insert
the pushrod tube through the hole in the firewall. Push it in
until it protrudes 1" [25mm] in front of the firewall. Use
medium CA to glue the tube to the firewall, but leave it free
inside the fuselage until the servos are installed.
Note:
The engine has been removed from the above picture
for clarity.
9
