The 2-stroke Glow Engine is the simplest of all the types of RC
airplane engines. The term 2-stroke means that the engine fires on
every stroke of the piston.
There are no moving valves. The induction of the fuel/air
mixture and exhaust are accomplished by ports in the cylinder
walls. This feature makes the 2-stroke simpler and lighter than a
similar capacity 4-stroke engine.
As it fires on every stroke, it is also more powerful than the same
size 4-stroke engine. To sum up- the 2 stroke is lighter, simpler, more
powerful and requires less maintenance than a similar sized
4-stroke.This makes it the ideal engine for the beginner.
The disadvantages of the 2-stroke are it is more difficult to muffle efficiently and it
does tend to use more fuel.
MAINTENANCE.
As always please follow the manufacturer's instructions. Use only the
recommended fuel (well filtered) and propeller size. Do not run the
engine too lean, especially when the engine is new. Please follow
the manufacturer's "break in procedure" . Note that the engine shown in
the above photo needs no break in routine and is built especially for the
beginner.
At the end of each flying session, make sure to empty the
tank and run the engine "dry" of fuel. A small drop of
after-run-oil inserted into the carburetor will ensure the inside
surfaces and bearings are well protected from the negative effects
of some fuels.
Of all of today's rc model airplane engines, the 2-stroke has to be the
simplest to maintain.
TYPES AND SIZES AVAILABLE.
The range of sizes of 2-stroke glow engines generally available
is from 0.10 cu.in.(1.76 cc) to 2.13 cu.in. (35cc). The vast majority are
all single cylinder models. Because of it's popularity it is probably the
most developed rc model airplane engine available.
Main bearings can be either plain or ball bearing. Plain
bearings are generally used on the smaller size engines and the less friction
developed by the ball bearing, means it can be found in the higher performance
and larger displacement engines.
STARTING AND RUNNING
PROCEDURE.
Please make sure the fuel is clean by installing a filter in
your fuelling system and also in your on-board set-up.
Turn the radio system "on". Choke the engine, usually by
placing a finger over the carburetor air intake and rotating the
propeller a few times. Be careful not to overdo it and flood the
engine! Next attach the glow plug igniter. Now the engine should be
ready to run.
Make sure the model is safely constrained by a device or a helper
and ensure the throttle is set to "low" on the transmitter.
Apply the electric starter. I believe this is safer than
"flipping" the propeller by hand.
The engine should now start and run at low speed. Now move
behind the propeller and remove the glow plug igniter. NEVER try
to reach over the rotating propeller to make adjustments! Ensure
the model is still safely constrained and slowly advance the
throttle to high.
If necessary, adjust the high speed needle valve to achieve a
reliable maximum RPM (revolutions per minute)
Do not try and squeeze the last few revs out of the engine!
A test to see if the needle is set too lean is to raise the nose
of the aircraft to a vertical position and then advance the
throttle to high. If the engine continues to run at the same speed as
when it as horizontal, then it is not too lean. Please be very careful
when performing this test! A spinning propeller is an obvious danger
to yourself and others.
Make sure the engine is reliable at all throttle settings before
you fly. Make all the adjustments to high speed and low
speed needle valves required to achieve complete reliability. Adjust the
low throttle setting to give a reliable low RPM for landing,
without the engine stopping.
Allow the RC model airplane engine to run at this low speed for a couple of minutes
and then advance the throttle to high. It should smoothly increase in
speed with no hesitation
