REVO PLATINUM EDITION • 7
THE TRX 3.3 RACING ENGINE
If 33% improves power, then it seems that the highest nitro content
available (beyond 33%) should always be used in the engine. In reality,
there are practical limitations. Engines are designed to run best within
a range of nitro percentages. How the engine is ported, the size of the
combustion chamber and other factors determine how much nitro can
be efficiently used in the engine. The TRX 3.3 Racing Engine responds
exceptionally well to a maximum of 33% nitro, returning cooler temps,
more power, and a smoother throttle response. For those who want to
run higher nitro, 33% Top Fuel is the optimum nitro percentage for the
TRX 3.3 Racing Engine. Increasing the nitro beyond 33% can introduce
the need for engine modifications (ports, head shimming, etc.) to avoid
starting and tuning difficulties. There are limits to how much nitro an
engine can effectively use to make more power. Lower nitro percentages
have their own advantages. Nitro is an expensive component in the
fuel so 10% nitro blend is more economical for the sport user. 10% also
provides greater latitude with the needle settings for easier tuning.
When using Traxxas Top Fuel, using higher nitro percentages does not
cause the engine to wear out faster. 33% Top Fuel contains the same
quality lubrication package as 10 and 20% Top Fuel. Some non-Traxxas
high-percentage nitro racing fuels do sacrifice some lubrication in
attempts to increase performance. We urge you to not take chances with
your engine investment and use Top Fuel for consistent performance and
long engine life.
Handling the Fuel
•
Follow all directions and warnings on the fuel can.
• Keep the fuel tightly capped at all times. Some components in the fuel
can evaporate very quickly and upset the balance of the fuel.
• Do not store unused fuel in the fuel dispenser. Immediately return fresh
unused fuel back into the fuel can.
• Do not mix old and new fuel. Never mix different fuel brands together.
• Store the fuel in a cool dry location, away from any source of heat,
ignition, flame or combustion.
• Read and follow the safety precautions on page 3 in this manual.
BREAKING IN YOUR TRX 3.3 RACING ENGINE
The TRX 3.3 Racing Engine uses a ringless, aluminum-brass-chrome (ABC)
piston/sleeve construction. This type of engine design relies on a very precise
running fit between the piston and sleeve for cylinder sealing.
Engine break-
in is necessary to allow the piston and sleeve to develop an extremely
precise fit and optimum cylinder sealing. Therefore, proper engine break-
in is critical to achieving the fastest, most reliable engine performance.
Allow yourself about 1 to 1
1
/
2
hours to complete the break-in procedure. The
engine break-in period will take 5 tanks of fuel in a Revo. The break-in time
is not the time to impress your friends with your new Revo.
You must wait
until the engine is fully broken in before attempting sustained high speed
running.
Patience and careful attention during break-in will reward you with
the best-performing TRX 3.3 Racing Engine possible.
During break-in, your engine may appear to malfunction with symptoms
like stalling, inconsistent performance, and fouled glow plugs. These are
simply the normal “break-in pains” engines sometimes go through. They
will disappear once your engine is fully broken in. Many owners report
not experiencing any of these symptoms with TRX Racing Engines.
We
recommend to go ahead and replace the glow plug with a new one after
the engine break in procedure.
Engine Break-in Procedure
The focus during break-in is to vary and limit the engine speed. This will
be accomplished by accelerating and stopping at different rates for the first
5 tanks of fuel. As the engine begins to break-in, the duration and intensity
of the acceleration will gradually increase.
Sustained high-speed running
is not permitted until the 6th tank of fuel.
Perform the initial break-in
on a large, flat, paved surface.
Revo is very fast and by tanks 4 and 5 you
will need plenty of room for the truck to run in. Apply all throttle and
braking actions gently. Abrupt acceleration or braking could cause the
engine to stall unnecessarily.
• Special break-in fuels are not recommended. Use the same fuel you plan
to use everyday.
• If possible, avoid breaking-in the engine on extremely hot or cold days
(see page 9).
• Pay careful attention to the fuel level. Do not allow the fuel tank to run
completely empty. An extremely low fuel level causes the mixture to
run too lean. This could result in a burned glow plug or extremely high
engine temperatures.
•
Do not attempt to break in the TRX 3.3 Racing Engine by idling it on a
stand. This will produce poor results.
• Keep extra Traxxas glow plugs handy. The break-in process can cause
deposits to form on the plug leading to plug failure.
• Change or clean your air filter after break-in.
• Follow the instructions exactly for each of the first 5 tanks of fuel.
• Never run your Revo indoors. Since the TRX 3.3 Racing Engine
exhaust fumes are harmful, always run your model outdoors, in a
well-ventilated area.
• Read and follow the safety precautions on page 3 in this manual.
Starting Your TRX 3.3 Racing Engine for the First Time
Before you start your TRX 3.3 Racing Engine for the first time, make sure
you have read all instructions and precautions in this manual.
Pay close
attention to the tank-by-tank break-in instructions in the next section,
and make sure you have read and understood them before you run
your engine.
Your engine must be at room temperature (70°F or 21° C) or above the
first time you start it
. If it’s cooler than room temperature outside, remove
all fuel and keep your Revo indoors until you’re ready to start it and then
take it outside. If it’s colder than 45 degrees, special considerations should
be made. See cold weather break-in on page 9. We do not recommend
running the model in temperatures below 35 degrees.
Note: The initial startup fuel mixture settings have been pre-set at the
factory. Do not change the settings.
1.
Turn on the radio system
.
2.
Make sure the throttle trigger on the transmitter is in the idle
(neutral) position.
DANGER! Model engine fuel is poisonous to humans and animals.
Drinking the fuel can cause blindness and death. Handle with care
and respect. Keep it out of reach of small children at all times! While
driving, do not leave your fuel dispensing bottle on the ground
where a child could have access to it. Follow fuel label warnings.
Your TRX 3.3 Racing Engine doesn’t usually require priming. If you
do need to prime your engine, watch the fuel line carefully to avoid
flooding your engine.
People have differing opinions on what is the proper procedure
to break-in a model engine.
Only use the Traxxas break-in
procedure. Other break-in procedures could result in a weak,
damaged, or otherwise poor performing engine.
The procedure
outlined here was extensively tested and proven to yield better
performing engines than other “common” break-in methods.
Even if you have years of experience using model engines, please
do not ignore this caution!
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