Whay is 14.7:1 air fuel not important in a Diesel?

[Agent WD-40]

Thanks for the great response. That is what I was looking for.

[lelandstanford]

I am overwhelmed with all the informative responses. Thanks guys!

Now I know diesel engines are better than I thought they were.

[hartrepair]

In a diesel if all the air available in the combustion chamber is consumed in combustion then an over heat situation seems inevitable. Combustion is forced on the fuel injected by virture of the heat and oxygen,rather than a carefull mixture and a spark. Interestingly a jet engine is similar in that,although a 14.7 :1 mixture is achieved,it only pertains to about 25% of the air going through the engine. The rest is used for cooling. In a jet engine if fuel flow is increased too greatly there will be large power developed ....as well as molten metal. Therefor as with the diesel the power developed is controled by the fuel quantity with air being uncontroled