Knock Detection Kit.

Knocking :

Knocking is uncontrolled combustion, caused by the spontaneous ignition of portions of the mixture, which have not yet been reached by the advancing flame front, triggered by the ignition spark. Combustion takes place considerably faster than normal ( gentle ) combustion. There are pressure oscillations with high peak pressures and high frequencies which are superimposed on the normal pressure curve. The consequence of knocking is overheating of parts of the engine, thus causing pitting on the pistons which, if allowed to progress, influences the lubricating properties and usually leads to auto - ignition and thus to destruction of the engine.

The pressure oscillations severely stress the cylinder head, the spark plugs, the valves, the pistons, the connecting rods and the crankshaft. If knocking is not noticed or is not remedied, serious damage to the engine is inevitable.

Knock Detection Kit :

The kit was designed to reliably pickup and hear knock whilst the engine is on the test bed, rolling road or out driving the vehicle, as well as a useful aid during programming an engines management system.

Kit comes complete with control unit, head phones, knock sensor, plus all wiring and connections supplied in aluminium carrying case. The unit is portable with its own 9 volt battery or can be powered by a 12 volt supply.



Operation :

The knock sensor picks up structure-borne noise at a suitable point on the engine, and converts it into an electrical signal which is input to the control box, amplified and filtered. With the head phones connected and the engine running the unit control knob can be adjusted to reduce unwanted engine noise so when knock occurs it is easily detected.