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Read on if you would like to know about Air to fuel ratio and its effect on power and temperature in the internal combustion engine.
Air Fuel Ratio
Anyone who reads car forums can't read for long before the A/F ratio is mentioned. Everyone knows that a lean condition is detrimental to the engine at high load and a rich condition is best. When questions are raised concerning why this is so, some of the replies might include: "Lean burns hotter and can damage exhaust valves, lean mixtures are more prone to detonation, rich burns cooler because of the extra non burning fuel sucking up the heat. These statements all have some truth in them, but here are the real reasons.
The stoichiometric air/fuel ratio, the ratio at which there is just enough air to completely burn all the fuel is 14.7:1 Air: Fuel for gasoline. The fuel is burned completely to water and carbon dioxide. Using simple chemistry, one would assume that this mixture would provide the maximum temperature and hence power output, but this is not so in practice, a slightly rich mixture is needed for that. Think about it for a second. You get more power with a mixture that has extra fuel. Wouldn't that extra fuel, which can't burn because there is not enough oxygen, take heat away from the combustion process as it evaporates, lowering the power output?
Think about this and if you think you have the answer, click on the next page for the answer.
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