- #1
varnish
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Hey guys,
Combustion in an SI engine.
So an AF:R of 14.7:1 is stoichiometric for petrol (gas), but an AF:R of 12.5:1 makes more power.
One common thought is that not all the fuel and oxygen react in a stoichiometric mix, so by upping the fuel there is more chance of all the oxygen reacting (excess fuel).
For some reason I have got the notion that when the CO2 and h2o in the cylinder dissociate, the liberated oxygen is free to react with the excess fuel.
But I can't find any sources that state this, they all talk about equilibrium reactions and NOx production.
So question is, what is happening to make the extra power when using a rich mixture.
Combustion in an SI engine.
So an AF:R of 14.7:1 is stoichiometric for petrol (gas), but an AF:R of 12.5:1 makes more power.
One common thought is that not all the fuel and oxygen react in a stoichiometric mix, so by upping the fuel there is more chance of all the oxygen reacting (excess fuel).
For some reason I have got the notion that when the CO2 and h2o in the cylinder dissociate, the liberated oxygen is free to react with the excess fuel.
But I can't find any sources that state this, they all talk about equilibrium reactions and NOx production.
So question is, what is happening to make the extra power when using a rich mixture.