Internal timing

Definition

In a magneto, the precise relationship between the position of the rotating magnet and the opening of the breaker points (or equivalent triggering device). When the magnet is in the position that produces maximum magnetic flux change (the E-gap position), the points must open to induce the highest possible voltage in the secondary coil for the spark plug.

Plain English

It is the timing inside the magneto itself — making sure the points open at exactly the right moment in the magnet's rotation so the magneto produces the strongest possible spark.

Context Anchor

Seen in aircraft engine ignition maintenance, especially when inspecting, overhauling, or installing magnetos.

Derivation

"Internal" because this timing happens inside the magneto, between its own moving parts. It is set and checked separately from external timing, which is the timing of the magneto to the engine's crankshaft.

Why Pilots Care

Proper internal timing prevents late or early ignition that can cause detonation, power loss, or engine damage.

Analogy

It is like setting the hands inside a clock correctly before hanging the clock on the wall. If the clock itself is wrong, placing it neatly on the wall will not make it show the right time.

Intuition Check

Do not confuse internal timing with timing the magneto to the engine. Internal timing is the setting inside the magneto; engine timing is how that magneto is positioned on the engine.

Example Sentence 1

After reassembling the magneto, the technician set the internal timing by aligning the rotor to the E-gap position and adjusting the points to just open.

Example Sentence 2

Once internal timing was complete, the magneto was installed and external timing was verified against the engine timing marks.

Definition

The timing of the breaker points inside a magneto relative to the position of the magneto's rotating magnet. Internal timing sets the exact moment within the magneto's rotation when the points open to produce the high-voltage spark, which occurs when the magnet is in its E-gap position (the position of greatest magnetic flux change).

Plain English

It is the adjustment that makes a magneto fire its spark at the right point in its own internal rotation. The breaker points must open at the precise moment the magnet is positioned to generate the strongest spark.

Context Anchor

Seen in aircraft engine ignition and magneto maintenance discussions, especially before a magneto is installed or timed to the engine.

Derivation

Called 'internal' because this timing is set inside the magneto itself, independent of the engine. It is contrasted with external timing, which aligns the magneto to the engine's crankshaft position once the magneto is installed.

Why Pilots Care

Correct internal timing is required for reliable ignition, smooth engine operation, and prevention of starting or running problems.

Analogy

It is like setting a clock mechanism correctly before hanging the clock on the wall. The clock must work correctly inside itself before it can be lined up with anything outside it.

Intuition Check