What causes detonation under load?
Detonation occurs when excessive heat and pressure in the combustion chamber causes the air/fuel mixture to ignite on its own. This causes a sharp, sudden rise in cylinder pressure which subjects engine internals—pistons, rings, bearings, gaskets, etc.
What is the most common cause of detonation in an engine?
Detonation is generally caused by excessive heat, excessive cylinder pressure, improper ignition timing, inadequate fuel octane or a combination of these. Of the previous, excessive heat is usually the culprit. As an engine is modified to generate more power, additional heat is produced.
What types of engine failure can occur from detonation?
Detonation will cause piston and ring damage, top ring groove wear, scoring, or piston scuffing and cylinder wall damage, sticking rings, loose head gaskets and possible bearing damage leading to complete engine failure.
What happens when a detonation occurs in an engine?
Mild or occasional detonation can occur in almost any engine and usually causes no harm. But prolonged or heavy detonation can be very damaging. So if you hear knocking or pinging when accelerating or lugging your engine, you probably have a detonation problem. A DOZEN WAYS TO PREVENT DETONATION 1. Try a higher octane fuel.
Which is an example of a bearing failure caused by detonation?
Examples of bearing failures caused by detonation. Left: Fatigue of intermediate copper based lining found in tri-metal bearings. Right: Localized excessive wear due to connecting rod distortion from detonation. When tuning an engine, fuel is used as a form of temperature control.
How does idler gear affect the gear ratio?
The direction of rotation is reversed from one gear to another. The only function of the idler gear is to change the direction of rotation. It has no affect on the gear ratio. The teeth on the gears must all be the same size so if gear A advances one tooth, so does B and C. t = number of teeth on the gear.
Which is the better grade of gasoline for detonation?
The octane rating of a given grade of gasoline is a measure of its detonation resistance. The higher the octane number, the better able the fuel is to resist detonation. Most engines in good condition will run fine on regular grade 87 octane fuel.