Internal Combustion Engines
The reference fuels for knock rating of spark ignition engines would include

Normal octane and aniline
Iso-octane and normal hexane
Iso-octane and alpha-methyl naphthalene
Normal heptane and iso-octane

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Internal Combustion Engines
In a typical medium speed, 4-stroke cycle diesel engine

Fuel injection starts at 10° before top dead center and ends at 20° after top dead center
May start and end anywhere
Fuel injection starts at top dead center and ends at 20° after top dead center
Fuel injection starts at just before top dead center and ends just after top dead center

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Internal Combustion Engines
Flash point of fuel oil is

Minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame
Indicated by 90% distillation temperature, i.e. when 90% of sample oil has distilled off
Temperature at which it catches fire without external aid
Temperature at which it solidifies or congeals

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