Timing - Knock Parameters / Channels
No discussion of timing would be complete without the subject of knock, (engine knock also commonly known as pinging) or more specifically
Knock Retard.
Engine knock is caused by the piston still coming up in the cylinder and the spark igniting too soon forcing it down before the piston had the chance to reach top dead center and began its decent downwords.
Have you ever pushed a friend or a sibling on a swing and and stood too close and had the swing slam into you, well you experienced something very similar to engine knock, had you stood further back the swing would have reached the end of the pendulum (equivalent of TDC for a piston) and began to swing back on it's own, just as the piston would start falling back down in the cylinder, then if you gave the swing a push it would be as if the piston had proper timing set to ignite the flame somewhere after TDC to push the piston down just like you pushing the swing much easier.
Knock Retard is the PCMs way of protecting itself from literally blowing up the engine. So lets add the three Channels related to Knock:
- Knock Retard
- Burst Knock Retard
- Knock Learn Factor