string at the cabin area firmly to the ends of the two fuel lines.
Apply a generous bead of silicon sealer around the neck of the fuel
tank. Remember that the correct orientation of the fuel tank within
the fuselage is with the neck of the tank "up" when viewed from the
front. Insert the tank into the fuselage from the cabin area, lightly
pulling the string from the front and guiding the tank into place
from the rear. Pull the fuel lines through the hole in the firewall and
press the tank firmly into the round hole. We used a scrap piece
of sponge rubber to temporarily hold the tank in this position.
Apply a bead of glue (thick CA glue works well here) to each side
of the 1/8" lite-ply fuel tank former, where it will contact the sides
of the second fuselage former. Fit the former in place through the
cabin and onto the rear of the fuel tank. Press it firmly against the
fuselage former.
The 5/16" x 3/4" x 5" balsa tank retainer is now installed against
the back of the tank, between the fuselage sides. Position the
retainer piece squarely and apply a few drops of CA glue to hold it
in place. If the tank should ever need to be removed, the retainer
can be easily broken free allowing the tank to be slid back out.
Remove the scrap piece of foam rubber supporting the tank and
connect the fuel lines to the fueling valve and engine.
❑
15) We made a simple thin sheet metal bracket to attach and
direct the fuel tubing coming from the engine drain fitting, to the
firewall. We left about 1/2" or so of this tubing hanging below the
firewall. The four cowl mounting screw holes in the fuselage sides,
at the nose, should now be "hardened". Place a couple of drops
of thin CA glue into each screw hole. This hardens the threads and
also, serves to make these holes fuel-resistant. The cowl will be
final-mounted to the fuselage in the Spinner Assembly section.
This completes the installation of your 4-stroke engine. Skip the
GASOLINE ENGINES section, moving to the FUSELAGE
PREPARATION & SERVO INSTALLATION instructions.
GASOLINE ENGINES:
The Rascal 110 is a good subject for smaller gasoline engine
power. There are several such engines on the market, including
the RCS 1.40 and other similar sized motors. Keep in mind that
there are some considerations when choosing a gas engine for
this model. One of these is the required width of the mounting bolt
pattern on the firewall and the firewall spacer needed to move the
engine forward from the face of the firewall, toward the front of the
cowl. Since it is likely a given that gasoline engines used in this
model will be installed inverted, then another consideration is the
engine's muffler. The ideal gas engine set-up would be an inverted
installation with a Pitts-style muffler contained within the cowl.
The gas engine we used for our Rascal 110 is the new F.P.E. 1.3
with electronic ignition. This engine fulfilled all of our installation
and mounting criteria, as well as having a nice Pitts-style muffler.
This engine produces very good power, turning a 16 x 8 prop at
7400 rpm.
This airplane/power combination has produced a
consistently "fun" airplane to operate and fly. Making the use of
this engine even easier is the fact that SIG produces laser-cut
engine spacer/mounts that are ready to use. These are cut from
rock-hard 1/4" plywood and the package contains two spacers.
For our F.P.E. 1.3 installation, we needed 1" of spacing and
therefore used four of these spacers.
For reference, the part
number for these spacers is SIGSH806.
Another important consideration, when setting up this or any
gas engine powered model, is the adequate separation of the
radio system components from the engine's ignition system
components. The general rule of thumb states that there should
be at least 12" of separation between these two systems. This
means everything; switches, battery packs, all wiring, etc. The
reason for this separation is that the engine's ignition system may
"talk" to the radio system via RF (radio frequency) emissions, thus
causing interference.
In the real world, 12" of separation may not always be possible. In
our gas powered Rascal 110 models, we had no problem
separating the two systems by 11-1/2" - the two closest
components being the two switches (one for the ignition system
and one for the radio system).
This component separation,
coupled with a good radio system and the engine's
RF-suppression sparkplug, has made our Rascal 110's "glitch"
free. For reference, we have always flown our gas powered Rascal
110 models with FM radio systems, with no problems. PCM radio
systems are said to be more selective and therefore more resistant
to RF emissions.
❑
1) If you've chosen a different make of gas engine for your
airplane, you'll first have to create a firewall spacer/mount from
hardwood or 1/4" plywood. The engine needs to be mounted with
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