accommodate any standard glow engine in the specified size
range. Drill the four mounting holes with a 9/64” or 5/32" drill bit.
❑
2) Install the M3 blind nuts on the back of the firewall. The
best method is to use one of your mounting bolts, with a flat
washer on it, from the front side of the firewall to “draw” the blind
nut into the back side. Keep tightening the bolt until the prongs of
the blind nut are completely locked into the plywood. After you
get all four blind nuts in place, apply a little glue around the flanges
of the blind nuts to keep them from coming loose. Be careful not
to get any glue in the threads of the blind nuts.
HELPFUL HINT: It’s never easy putting a blind nut on the backside
of the firewall of a pre-built model. Here’s a handy trick! Take a
stick of scrap balsa wood - 1/4” sq. x 10”-12” long works well in
most cases - and put a piece of doubled-up tape (any kind) on the
end, and then stick the blind nut to the tape. With this stick you
can reach inside the nose of the airplane and hold the blind nut in
position while you screw in the mounting bolt from the front of the
firewall. If the model structure doesn’t allow a straight shot at the
location, cut an angle on the end of the stick to allow you to hold
the blind nut at the correct angle.
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3) Bolt the engine mounts in place on the front of the firewall
with four M3 x 20mm mounting bolts, four M3 flat metal washers,
and four M3 split-ring lock washers. Leave the mounting bolts
slightly loose for now - do not tighten them until the next step.
❑
4) Set your engine in place on the beams of the engine
mounts. If the beams of the mounts are too far apart to fit your
engine, slide the mounts closer together. If they are already too
close together, slide them apart. Notice that the holes in the
mounts for the bolts are slotted to allow you to adjust the mounts
to fit your engine. After you get the mounts in correct position,
tighten all four mounting bolts, securing the engine mounts on the
firewall.
❑
5) Slide the engine forward or aft on the engine mounts until
the front of the engine's thrust washer is 4-1/2" from the front of
the firewall.
❑
6) Double check to make sure that the engine is pointing ex-
actly straight forward, and then mark the locations of the engine
mounting holes onto the beams of the engine mounts, using a
center punch or sharpened nail.
❑
7) Unbolt the engine mounts from the firewall and drill holes
thru the beams of the mounts at each location. We recommend
that you secure the engine mounts in a vise while you drill the
holes. Also, if at all possible, use a drill press to drill these holes.
You can drill them by hand, but if you have access to a drill press,
the job will be much easier and the holes will be straighter.
NOTE: Engines in the .40 to .46 size range are right at the break
point between using 4-40 size or 6-32 size mounting bolts. Some
.40-.46 engines have small holes in their case for 4-40 bolts, while
other .40-.46 engines have holes large enough to accommodate
6-32 bolts. Be sure to buy the size appropriate for your engine.
Drill 1/8" dia. holes if you are using the 4-40 mounting bolts.
Drill 5/32" dia. holes if you are using 6-32 mounting bolts.
❑
8) Re-assemble the engine on the engine mounts. Then bolt
the entire engine and engine mount assembly in position on the
firewall. Tighten all bolts firmly. We suggest using a little thread
lock compound (not supplied) on all the bolt threads to keep them
firmly in place.
FUEL TANK
Next figure out how you want to fuel and de-fuel your airplane, in
light of the fact that you have a full cowling surrounding the engine.
There are basically two choices.
Method 1
You can use traditional 2-line plumbing inside your tank, along
with an after market fueling valve. The 2-line plumbing has a fuel
feed line with clunk and a vent line to the top front of the tank.
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