Why must the charge in the combustion chamber be compressed before ignition?

Why must the charge in the combustion chamber be compressed before ignition?

The charge is the volume of compressed air-fuel mixture trapped inside the combustion chamber ready for ignition. Compressing the air-fuel mixture allows more energy to be released when the charge is ignited. Intake and exhaust valves must be closed to ensure that the cylinder is sealed to provide compression.

What is the compression ratio for most small engines?

Compression ratio is altered between 14:1 and 8:1 by separating the cylinder block (with fixed head) from the crankcase assembly, and tilting the block relative to the crank centerline. This effectively increases the combustion chamber volume, providing a numerically lower compression ratio.

Can you run nitrous with high compression?

A: No. Nitrous oxide by itself is non-flammable. However, the oxygen present in nitrous oxide causes combustion of fuel to take place more rapidly. However when higher compression or higher horsepower levels are used a racing fuel with an octane rating of 100 or more must be used.

Is high compression better than low compression?

A higher compression ratio (CR) is beneficial for engines. That’s because the higher ratio allows for an engine to extract more energy from the combustion process due to better thermal efficiency. Higher compression ratios allow the same combustion temperatures to be achieved with less fuel.

What is considered high boost?

“high boost” is more in the limitations of the motor and the turbocharger than it is in “the tune”. and it varies depending on how built your engine it, what its compressions is… also on the size of your turbocharger… 21psi on a stock twin is considered really high boost….

What is a good compression test reading?

Healthy engines should have compression over 100 psi per cylinder, with no more than 10 percent variation between the highest and lowest readings. TIP For a cylinder below 100 psi, pour 1 teaspoon of engine oil into the plug hole and retest. If the reading jumps, the piston rings are worn. If not, think valve problems.