Fuel Systems

Question 1

Detonation

Answer 1

Occurs when there is a build up of heat and pressure

The end gas gets too hot and forms fulminate which causes a rapid, uneven rise in pressure within the cylinder (an explosion)

Question 2

Flame rate of detonation

Answer 2

300m/s

1000ft/s

Question 3

Controlling detonation

Answer 3

Most effective - adding lead to the fuel

Question 4

Increasing the risk of detonation

Answer 4

High power settings

Overheated cylinders

High power settings at low RPM

Question 5

Mixture ratios

Answer 5

15: 1 = Stoichiometric, chemically correct ratio
12: 1 = 30% rich, t/o and climb

> 15:1 = lean, cruise economy

Question 6

Weak mixture

Answer 6

Produces higher engine temp, slower burn gives more time for heat to be transferred to the body of the engine

A lean mixture gives you increased cylinder temp but reduced EGT

Reduces fuel consumption - 20% lean = best

Question 7

How to get an instant reading of lean/rich mixture

Answer 7

Check EGT

Reduces with a lean mixture