What is the difference between a hot spark plug and a cold spark plug?
A hot spark plug has a long path for the heat to travel between the nose core insulator and the spark plug shell. In a cold spark plug, the heat has a shorter distance to travel, and the spark plug operates cooler than a hot spark plug.
Why is it important that a torque wrench always be used when installing spark plugs in an aircraft engine?
If the spark plugs are not put in tight enough, there is the possibility of a poor seal, and if they are put in too tight, there is danger of cracking the insulation.
What is the purpose of staggered timing between the two magnetos on an aircraft engine?
The spark plug nearest the exhaust valve fires before the spark plug on the intake side. The flame front caused by the two spark plugs will meet in the center of the piston.
What is checked when a magneto is internally timed?
Internally timing a magneto consists of adjusting the breaker points so they will open at the instant the rotating magnet is in its E-gap position, and the distributor rotor is in the position to direct the high voltage to cylinder number one.
What is the advantage of fine-wire spark plugs over massive electrode spark plugs?
Fine-wire spark plugs have a firing end that is more open than that of a massive electrode spark plug. The open firing end allows the gases that contain lead to be purged from the spark plug so they will not form solid lead contaminates.
What is the function of the capacitor in a magneto?
The capacitor minimizes arcing at the breaker points, and it speeds up the collapse of the primary current as the breaker points open.
What is the basic difference between a low-tension magneto and a high-tension magneto?
A high-tension magneto produces high voltage in the magneto coil, and it is sent to the correct spark plug by the built-in high-voltage distributor.
Why is it important that the spark plugs be kept in numbered holes in a tray when they are removed from an engine?
Spark plugs tell a good deal about the internal condition of the cylinders from which they were taken. The mechanic can take the proper action when a spark plug indicates such conditions as detonation or overheating.
What type of ignition system is used on most turbine engines?
