The Trx 3.3 Racing Engine - Traxxas T-Maxx 3.3 4907 Owner's Manual

THE TRX 3.3 RACING ENGINE

INTRODUCTION
The TRX 3.3 Racing Engine is
®
the next generation of TRX nitro
power. The larger displacement
and advanced porting generate
class-leading horsepower while
still maintaining the TRX Racing
Engine characteristics of broad,
linear power delivery and ease
of tuning. Focused engineering
and rigorous testing have yielded
unprecedented power and
uncompromising performance
that turns ready-to-run into
Ready-To-Race® .
The TRX 3.3 Racing Engine takes a total-system approach. Each part of
the engine, from the air filter to the exhaust tip, is carefully engineered to
work in harmony with other engine components. Each part complements
the next, to extract maximum power. The TRX 3.3 Racing Engine is
designed to be tolerant of variations in tuning, and to run successfully
through a wide range of variable atmospheric conditions such as changes
in temperature, humidity, and altitude.
In order to get the longest engine life and keep the TRX 3.3 Racing
Engine in top running condition, it is very important to perform regular
routine maintenance. The number one cause of premature engine wear
and failure is lack of care and maintenance!
TERMS TO KNOW
You'll find these Nitro R/C engine terms throughout this section of the manual.
.15 - .15 or "15" refers to the displacement of the engine. The TRX 2.5 Racing
Engine is .15 cubic inches or 2.5 cubic centimeters (cc). The name "TRX
2.5" is derived from the cc measurement.
.20 - .20 or "20" refers to the size of the engine. The TRX 3.3 is .20 cubic
inches or 3.3 cubic centimeters (cc). The name "TRX 3.3" is derived from
the cc measurement.
ABC - Abbreviation for aluminum, brass, and chrome. Refers to engine
construction that consists of an aluminum piston that slides in a chrome-
plated brass sleeve. The TRX 3.3 uses ABC construction.
Air filter - The air filter sits atop the carburetor and prevents harmful dust
and dirt from entering the engine. Dirt ingestion is the number one cause
of premature engine failure so the engine should never be run without
the air filter in place.
BDC - Bottom dead center. The bottom-most position of the engine
piston stroke.
Break-in - Break-in is the procedure for running a brand new engine
according to specific instructions. This correctly prepares the engine for
normal running. The break-in procedure can be different for different
makes of engines. Follow the Traxxas directions for break-in exactly.
Carburetor - The carburetor atomizes (mixes) the fuel with the air so that
the engine can burn it. There are two types of carburetors; slide carbs and
barrel carbs. The TRX 3.3 uses the superior slide carburetor design.
Carb - Abbreviation for carburetor.
Traxxas strongly discourages changing or modifying any part
of the TRX 3.3 Racing Engine. Old tech tips and tricks that may
have boosted the power of other engines could seriously diminish the
performance of the TRX 3.3 Racing Engine.
BREAK-IN
The TRX 3.3 Racing Engine is manufactured to exacting tolerances and
requires a specially-designed break-in procedure to accomplish the final
precision fitting of the internal engine components. It is very important
that you follow the new break-in procedure as closely as possible to
achieve the best performance and longest life from your TRX 3.3 Racing
Engine. Engine break-in will take between one and two hours. Old style
break-in procedures, such as idling the engine on the bench for several
tanks of fuel or simply running the engine with a very rich fuel mixture
for the first 4 tanks of fuel, will not achieve the best results. Follow the
easy steps in this manual.
AIR FILTER MAINTENANCE
Dirt is the worst enemy to your engine. A clean air filter is absolutely
critical for long engine life. Due to the high performance nature of the
TRX 3.3 engine, a tremendous amount of vacuum is created to move a
large volume of high velocity air through the carburetor. This model is
equipped with a two-stage high performance air filter which requires that
the pre-filter stage be cleaned and oiled every hour of operation, and the
primary filter be cleaned and oiled every 3-4 hours. An extra pre-lubed
air filter set has been provided with this model to encourage you to
maintain the engine's air filter.
AFTER-RUN MAINTENANCE
Perform after-run maintenance on the engine to prevent corrosion
from building up on the internal engine components. The fuel naturally
attracts moisture and corrosion can build up very quickly inside the
engine if it is not prevented.
A few minutes spent before and after each time you run your model will
allow you to enjoy it for a long time to come. Read on for more exciting
details about your new engine.
Clean-out - Cleaning-out is a condition that occurs when the engine is
accelerating and the fuel mixture becomes sufficiently lean to allow
the engine to continue into its upper rpm power band. It is usually
characterized by a noticeable decrease in blue exhaust smoke and a
dramatic increase in engine speed.
Combustion chamber - The combustion chamber is machined into the
bottom of the cylinder head. This is where the glow plug ignites the fuel.
The shape of the combustion chamber is designed to promote more
efficient burning of the fuel.
Connecting rod - The connecting rod transfers the piston motion to the
crankshaft. The TRX 3.3 Racing Engine uses a "knife-edged" connecting
rod. The aerodynamic, sharpened edges allow it to "slice" through the
pressurized air/fuel mixture inside the crankcase.
Crankcase - The engine's "body" that contains all of the running
mechanical components.
Crankshaft - The main shaft of the engine that holds the
reciprocating assembly.
Cooling fins - The cooling fins are milled into the cylinder head and
crankcase and cause heat to be drawn away from the engine. Heat is
removed when it dissipates into the air passing across the cooling fins.
It is important to keep the fins clean of dirt and debris for maximum
cooling efficiency.
Cylinder head (head) - The finned aluminum part on top of the engine that
is responsible for dissipating most of the engine's heat. The combustion
chamber is machined into the bottom of the head.
There's more advanced thinking, development and testing in the
stock parts of your TRX 3.3 Racing Engine than in many aftermarket
manufacturer's performance parts. The TRX 3.3 Racing Engine is already
the most powerful engine in its class and may not benefit from average,
low-tech, aftermarket bolt on performance items.
T-MAXX 3.3 OWNERS MANUAL • 11