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Thursday, 17 April 2008 12:10
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There is nothing more important in the life of an engine both for its longevity and performance than to run it in properly. Skimp on the running in and it's almost a certainty that you will have problems with an engine.

This is a boring task but in the long run will give you a longer lasting and more reliable engine. The lubrication for all the internal parts of the engine is mixed into the fuel, this is why the running in process is important. Before starting an engine run fuel through the system and through the engine, when starting go slow and careful not to cause any damage by over revving . By running the engine rich to begin with you are ensuring there is plenty of lubrication available to all the new parts as they bed into place.

Although an engine running to lean will run faster than one running rich the fact that less lubricant is getting to the moving parts will cause excess friction, overheating, loss of compression and in extreme situations the engine will seize. Run the engine rich for around six tanks before you lean the engine and make it race ready. It is recommended to run the engine in while driving around and not sitting on blocks, during this process max rpm should not be reached.

After six tanks slowly start to lean the engine, turning the main jet needle clockwise, ensuring there is smoke from the exhaust at all times. As a general rule the engine shouldn’t run above 100deg C in any application. If you continue to lean the engine you are reducing the oil level in the engine and increasing wear and heat. The low end bottom needle is designed to improve idling and quicker engine response to full throttle. The bottom needle should be turned cautiously one eighth of a turn at a time in a clockwise direction (leaning the mixture). This action is necessary if the motor hesitates and blows a lot of exhaust smoke when the throttle is initially opened. On the flip side if the engine initially has no smoke and when it returns to idle the engine cuts then richen the bottom needle.

Hydraulic lock. Excess fuel in the chamber. Remove the glow plug, turn the car upside down and allow excess to fuel to run away

Ignition problems. Remove the plug and try lighting the plug, if there is not a strong glow the wire in the plug may have broken but first check the ignition battery

Fuel starvation. Check all pipe work and fuel tank for blockages. Be careful when removing the needles from the carb to ensure exact replacement once cleaned. Settings to lean top and bottom.

Wrong type of fuel. When choosing a fuel you should select a well known brand and one which will suit your application. On road engines are designed to use less oil (5-8%) than off road (10-12%). Also make sure to check you use the correct Nitro content for your engine. Check instructions for the correct recommendations.

No idle. Engine too lean on bottom so starving the engine, or too rich so flooding the engine with fuel. No compression between piston and sleeve, engine has become to hot and worn out. Idle to closed when carb is shut. Wrong type of fuel for your engine.
When running the engines it is just as important to keep the air filters clean and well oiled. This will help keep the internals of the engine clean and again reduce wear and increase life and reliability.

After-Run Oil. It's recommended that you remove the glow plug and place a couple of drops of After-Run oil in the cylinder as well as in the carb throat.

AM. Amplitude Modulation. Most RTR or ready-to-run kits come with an AM radio system, which is suitable for most newcomers. More serious racers will opt for FM or PCM radios that are less prone to glitching.

Ball End. The ball and is a metal ball with a hex and screw threads on one end. A ball cup attaches over the ball end to provide a pivot point.

Bearing. This is essentially a metal "donut," with tiny balls inside which permit rotating shafts to spin more efficiently. Bearings are widely considered to be the firest upgrade necessary for any kit that includes bushings.

Body Reamer. The body reamer is a must-have tool for creating perfect body post holes in Lexan bodies and other semi-soft materials.

Break-In. A new nitro engine has to go through a break-in procedure to mate the engine's piston to the cylinder sleeve. This provides a longer life expectancy between rebuilds. Recommended procedures will vary by manufacturer and engine. Generally, an engine will need to be run rich and at no more than half throttle for the first 2-3 tanks of fuel. The entire procedure can consist of anywhere from 3-5 tanks of fuel, depending on the individual engine's instructions.

Bushing. A metal, and sometimes nylon, ¡§donut¡¨ that supports a rotating shaft (like an axle).Most metal bushings are made out of something like Bronze Oilite, a metal that is permanently lubricated.

Camber. This refers to the angle of the tires in relation to the ground, as seen from the front and rear of the vehicle Zero camber (90 degrees) refers to tires that are exactly perpendicular to the ground. Tires leaning toward each other have negative camber, while tires leaning away from each other have positive camber. A general rule lf thumb is to have a slight bit of negative camber and to be sure both tires maintain the same camber angle. For the most part you should always avoid positive camber.

Carburetor. This can also be referred to as a carb. this part of the engine controls the ratio of fuel and air entering the engine. There are two types of carbs that rotate. The rotary carb is most common among RTR kits and is fine most applications. The slide carb provides a quicker response and is therefore more desirable to the more serious enthusiast.

Chassis. Made from aluminum, plastic composites or woven carbon fiber, this is the main platform to which all other components attach.

Clutch Bell. The clutch bell attaches to the crankshaft of a nitro engine and meshes with the spur gear, performing the same function as a pinion gear on an electric motor. Changing the number of teeth of teeth on a clutch bell alters the way a vehicle performs. Fewer teeth produce more low-end torque, whereas more teeth increase top-end speed.

Clutch Shoes. Clutch shoes are made from aluminum or a composite material and are attached to the engine flywheel. They expand under increasing RPM to engage the clutch bell that, in turn, engages the spur gear to make the vehicle move.

Crank Shaft. The shaft that the flywheel and clutch bell are mounted to. It is attached at the back to the piston by means of a connecting rod. The up and down motion of the piston causes the crank to rotate.

Crystal. A small interchangeable element in radio systems that determines what frequency that radio will operate on. You will find a crystal in the transmitter and in the receiver.

Differential. A differential is a unit that transfers power from the input to output shafts. The differential, or ¡§diff,¡¨ enables the outside wheel of a vehicle to spin faster and travel farther than the inside wheel during a turn.

Discharger. Many battery chargers include a built-in discharging function. A better way to discharge your packs, however, is with a separate discharger that connects directly to the battery pack. One common style looks like c row of small light bulbs.

Dogbone. A metal driveshaft with a ball at each end that has a pin going through the center, the pin fits into a slot in the outdrive to transmit drive train power.

ESC. Electronic Speed Control. An electronic component that controls throttle input by regulating the current being sent through the motor.

Fail Safe. If the transmitter¡¦s signal is lost or interrupted a fail safe unit returns the servo to a predetermined position to avoid dangerous runaways. A battery failsafe is a safety feature which brings the throttle servo down to idle as a warning that the receiver battery¡¦s voltage is getting dangerously low.

Flywheel. The flywheel is the larger metal wheel that sits behind the clutch bell and aids the engine¡¦s crankshaft with momentum and idling. For more torque and smoother idle use a heavier flywheel; for improved top speed and throttle response use a lighter flywheel. On non-pull start models it also represents how to start the engine with the use of a bump starter or starter box

Clow plug: Resembles a miniature spark plug. A glow plug supplies the necessary heat for igniting the fuel/air mixture in an engine. A battery-powered unit sometimes called a glow starter is installed over the plug to heat the small wire filament inside the chamber. After the engine is running, the glow starter can be removed since the wire filament inside the plug is kept hot by the engine¡¦s ¡§explosions¡¨ within the chamber.

Header. This is the aluminum exhaust coupling that attaches to the engine¡¦s exhaust port. A muffler or tuned pipe is usually attached to this bent piece of aluminum tubing.

Lexan. This is a clear, plastic-like material that is vacuum-formed over molds to create different body styles. These bodies are then painted on the inside so that the paint does mot scratch off from less than perfect laps around the track.

Linkage (throttle. brake). Heavy gauge wire is used to connect servo horns to throttle and break controls.

Mechanical Speed Control(MSC). The MSC is a servo-driven device that uses resistors to regulate power transfer from the battery to the motor as a means of throttle control.

MHZ=Megahertz. Unit of radio frequency. Surface frequencies are 75 MHz and air frequencies of 72 MHz, and 50 MHz can be used for either ground or air applications. However, a FCC license is required to operate on the 50 MHz (am radio) band.

Muffler. All nitro-powered cars use some type of muffler to reduce the noise output and provide pressure to the fuel tank.

Needle Valve. A nitro engine can have from one to three? adjustment needles on the carburetor. They are used to adjust the air to fuel ratio. On most engines, the needle is turned clockwise to lean the mixture (allowing less fuel and more air to enter) and counterclockwise to richen (permitting more fuel and less air to enter)

NiCad (or nicd ) Rechargeable Nickel cadmium batteries, most commonly used to power radio transmitters and receivers. Also used in stick packs in electric vehicles.

Nickel-Metal Hydride(Ni-MH). Battery cells that do not have ¡§cell memory¡¨ with slightly less voltage than nickel-cadmium batteries. For the average enthusiast this means less maintenance.

Nitro / Nitromethane. This is a fuel additive that increases a model engine¡¦s performance. The ideal nitro content (measured by percentage) varies from engine to engine, but you will typically find 10 to 30 percent on the hobby shop shelf.

One-Way Bearing. This is a bearing that allows a shaft to turn in one direction only.

Pinion Gear. Electric RC vehicles use a pinion gear attached to the motor¡¦s shaft to turn the spur gear which in turn spins the rest of the drive train.

Piston. The piston fits into an internal cylindrical part of an engine called a sleeve and slides up and down during the combustion cycle the piston turns the engine¡¦s crankshaft via a connecting rod, converting the energy of combustion into rotational torque. The piston and sleeve of an engine are replaceable but must both be replaced at the same time.

Pitch. In its simplest terms, this refers to the size of a gear¡¦s teeth. For instance, a 32-pitch pinion gear has smaller teeth than a 48-pitch gear. The number represents how many teeth per inch .

Power Supply. A device that converts 110VDC to 12VDC.Generall used to power charging equipment.

Preload (shock). Adjusting preload on shock absorbers determines a vehicle¡¦s ride height .It is adjusted either by clip-on spacers or by tension clamps. Threaded shock bodies use a metal ring that is rotated up or down to adjust preload.

Prototype. A full-scale working model of an original new product or an updated version of an updated version of an existing product.

Receiver (Rx). The servo and ESC plug into this electronic unit in an RC vehicle. The receiver converts the radio signals from the transmitter into servos and/or electronic speed controls commands.

Resistor. The resistor is the ceramic unit on an electric vehicle¡¦s mechanical speed control(MSC)that limits the amount of current transferred from battery to motor. It dissipates the energy as heat.

Reverse Lockout. This is an ESC function that prevents accidental engagement of reverse function on an ESC. Reverse is generally not permitted in organized racing, in
order to prevent track mishaps.

Rich. When the needles on the carb are set such that the engine is getting too much fuel it is referred to as running rich. If you accelerate from a stop and the engine dies, you are probably running too rich. And should lean out the engine¡¦s low speed idle adjustment a little (by turning the needle valve or low-end adjustment slightly clockwise).

RPM. Measurement of engine speed; the number of rotations / revolutions per minute.

Runtime. Total length of time a vehicle will run on a single battery pack or tank of fuel.

Servo Reversing. This is just what it sounds like. Radios with this function allow the user to reverse the output of the servo. This is useful when you switch the radio system between vehicles that may use different servo placement or orientation.

Servo. This is the unit that actually does the physical work inside your vehicle. A servo contains a small motor that, when activated by commands from the transmitter, moves the control linkages for steering, throttle and brakes Some vehicles with 3-channel radios have a third servo to activate other functions, such as reverse or shifting of gears.

Servo Savar. A device that protects the servo from excessive force that could damage its gears. It can be integrated into the control horn or the steering bellcrank.

Shock Piston. A small plastic, brass or nylon disk that travels up and down inside an oil-filled shock body. It uses a hole or holes to regulate that rate at which the shock compresses and rebounds.

Slipper Clutch. This refers to a device found primarily in off-road vehicles that allows the spur gear to slip under excessive load. This feature protects the driveline from excessive wear and, when set properly, makes it easier to drive in loose conditions.

Spur Gear. The large gear that meshes with a pinion gear or clutch bell to provide power to a vehicle¡¦s drivetrain.

Stagger. The difference between the circumferences on the left and right side tires, In oval racking, a positive stagger means the outside tires are larger than the inside.

Tire Truer. On-road racers running foam tires are likely to have a truer in their pit boxes. When the foam donuts become worn or damaged, the surface can be renewed with a tire truer, a machine that operates in the same manner as a lathe.
Toe Angle. When seen from above, a car¡¦s front wheels will point inward when the steering trim is set to neutral. Applies to the near wheels as well. This provides some degree of stability. Too much toe angle will slow you down.

TQ. Top Qualifier. The driver who turns the most laps in the shortest amount of time. In full scale racing this is known as the pole setter.

Transmitter. The part of a radio system that is used by the driver to control a vehicle. The transmitter sends signals based on a drivers input to a receiver that is mounted in a vehicle.

Transponder. This is a small electronic device mounted in a race vehicle. It transmits a signal to a receiver located at the start / finish line. The receiver records a vehicle¡¦s position and lap times during a race for scoring purposes.

Tuned Pipe. This is an upgrade for any vehicle equipped with a muffler. It is designed to increase an engine¡¦s power output. Different tuned pipes are available for different applications. Some provide increased top speed while others aid off-the-line power.

Universal Dogbone. A universal dogbone is a driveshaft that combines a conventional dogbone and axie into a single, more efficient unit.

Last Updated on Thursday, 17 April 2008 17:58