Search results
Results From The WOW.Com Content Network
In spark-ignition internal combustion engines, knocking (also knock, detonation, spark knock, pinging or pinking) occurs when combustion of some of the air/fuel mixture in the cylinder does not result from propagation of the flame front ignited by the spark plug, but when one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front.
With older engine designs, backfiring can be common or unavoidable. Backfire is rare in modern vehicles with fuel-injection and computer-controlled fuel mixtures. Cars with sports exhausts (both factory-fitted and aftermarket) are much more likely to backfire. In some circumstances the backfire is seen as an additional perk of the car.
Pressure in cylinder pattern in dependence on ignition timing: (a) - misfire, (b) too soon, (c) optimal, (d) too late. In a spark ignition internal combustion engine, ignition timing is the timing, relative to the current piston position and crankshaft angle, of the release of a spark in the combustion chamber near the end of the compression stroke.
An engine misfire, see engine knocking A song on Queen's album Sheer Heart Attack A malfunctioned cartridge that fails to discharge at all ( dud ), doesn't discharge promptly ( hang fire ), or only partially discharges ( squib load ) when being shot from a firearm.
LSPI events are random and infrequent, and their effects on impacted vehicles can include very high-pressure spikes, loud knocking noises and sometimes catastrophic engine damage. [4] It's commonly known as "Detonation or Knock". Engine management systems can overcome pre ignition by the means of a knock or detonation sensor.
The reduced engine speeds allow more time for autoignition chemistry to complete thus promoting the possibility of pre-ignition and so called "mega-knock". Under these circumstances, there is still significant debate as to the sources of the pre-ignition event. [3] Pre-ignition and engine knock both sharply increase combustion chamber temperatures.
Vehicles equipped with OBD-II diagnostic systems are designed to alert the driver to a misfire condition by means of illuminating the "check engine" light on the dashboard, or flashing it if the current misfire conditions are severe enough to potentially damage the catalytic converter. [62] On-board diagnostic systems take several forms.
Cooking off (or thermally induced firing) is unfired weapon ammunition exploding prematurely due to heat in the surrounding environment. [1] [2] The term is used both for detonation of ammunition not loaded into a weapon, and unintended firing of a loaded weapon due to heating.