13-03-2018, 12:03 AM
(12-03-2018, 11:30 PM)Tony Press Wrote:(12-03-2018, 10:26 AM)Colin Wilks Wrote: Film of a demonstration of ignition temperatures from 1948: https://youtu.be/yG0rP3D_0-s
Other sources quote the ignition temperature of a flammable mixture of petrol and air (1.4 to 7.6%) in a range between 230 and 280°C (https://hypertextbook.com/facts/2003/Sha...pher.shtml)
With the suggested C temperatures below I would think that some other parts of the combustion chamber could 'spark' auto ignition then (or am I totally confused) ?
- Intake manifold : 60
- Intake valve : 250
- Spark plug : 600
- Exhaust valve : 650
- Exhaust gases : 450
- Piston face : 300
- Cylinder wall : 185
- Piston ring : 220
- Piston skirt : 190
- Coolant : 105
- Engine oil : 70
If you accept the assertion in the article's last paragraph "[color=rgba(0, 0, 0, 0.92)]The flammability range of gasoline is between 1.4 and 7.6%. If the ratio of gasoline to air is less than 1.4%, then the mixture is to thin to burn. The mixture cannot burn when it contains more than 7.6% gasoline because it is too rich to burn." then perhaps it is only when the charge has started to be compressed that it falls within the flammability range?[/color]