Carbon Deposits

Within any combustion chamber, the process involves the conversion of the fuel – usually a hydrocarbon arrangement and the oxygen-supplied by the air to products of combustion. Ideally, if adequate time and a LEAN mixture are supplied, the resulting products should be steam (H2O) and carbon dioxide (CO2). Lubricating oil, in all internal combustion reciprocating piston engines, leaks past the scraper and compression rings (the amount being dependent upon their particular design the amount of wear of their sealing lips and whether or not they are permitted to move freely in the piston-ring grooves) and becomes a part of the fuel supplied. In real-working conditions inadequate time is available and hence, particularly when using RICH MIXTURES, unburned fuel in the form of carbon monoxide, unburned hydrocarbon and free carbon (as soot) emerge from the combustion process. The unburned hydrocarbons and free carbon form gum or wax, and are loosely described as carbon deposits, which are baked hard, in the combustion chamber, on to piston crown, valve heads (particularly the exhaust valve) spark plug and interior surface of the combustion chamber. This piston ring can also be seriously affected and eventually become stuck in their grooves.