What is the possibility of damaging my engine with too lean an air/fuel mixture?
This is a fair question to ask, as there has been many references made about engines leaning out and as a consequence burning valves and damaging pistons. The frequency of this question has therefore warranted a response by us. It is still of the held position that engines are kept at a constant air / fuel ratio of 14.7 / 1 primarily for the purpose of keeping the engine cooler by supplying extra fuel for its cooling ability. The actual reason for this ratio is that it provides the cleanest burn with the least amount of emissions. The term used for this is called stoichiometric, meaning that there is a perfect mixture of air and fuel to insure complete combustion. This air to fuel ratio also happens to be the hottest temperature hence why car manufacturers use this ratio to keep within the emission limits. This ratio provides the hottest burn for the least emissions. Either side of this ratio exhaust gas temperatures (EGT), will fall. If you go leaner than this the EGT will drop, and i
