Depends on if this engine is a 2 stroke, 4 stroke, or rotary engine. I assume you are referring to a 4 stroke as found in the vast majority of automobiles built today. The answer is, At the top of the compression stroke. The 4 strokes of a 4 cycle engine are:
# intake/induction stroke # compression stroke # power stroke # exhaust stroke
Depends on if this engine is a 2 stroke, 4 stroke, or rotary engine. I assume you are referring to a 4 stroke as found in the vast majority of automobiles built today. The answer is, At the top of the compression stroke. The 4 strokes of a 4 cycle engine are:
# intake/induction stroke # compression stroke # power stroke # exhaust stroke
Fuels are delivered to piston engines as a gas, either as natural gas or vaporized liquid fuel. Burning the fuel mixture changes the cool fuel into a hot vapor (CO2 and H2O). The hot vapor takes up more room than the cool inlet fuel and expands. The expanding gases move the piston.
The burning mixture of air and fuel forces the pistons downward during the power stroke stage of the four-stroke engine operation. This is when the spark plug ignites the compressed air-fuel mixture, causing a rapid expansion of gases that pushes the piston down.
This is during "combustion" which is the "power" stage of the operation.
The purpose of the spark is to ignite the air fuel mixture in the combustion chamber. When the air fuel mixture ignites the expansion of the burning air fuel mixture causes the piston to go down thus turning the crankshaft.
An internal combustion engine is one where a gas/air mixture is ignited and burned in a closed cylinder, and forces a piston to move. In other words, all piston engines in cars, trucks, bikes aircraft.
Piston effort refers to the force exerted by a piston in an engine as it moves up and down within a cylinder. It is a measure of the resistance that the piston encounters as it compresses air or fuel mixture during the power stroke and exhaust gases during the exhaust stroke. Proper piston effort is important for achieving optimal engine performance and efficiency.
Cars burn gasoline. Gasoline is pumped into the engine's intake, where it is mixed with air, called an air/fuel mixture. After it is mixed, a valve in the engines cylinder head opens and draws the air/fuel mixture into a cylinder. The valve closes and traps the mixture in the cylinder. In the cylinder is piston which moves up and compresses the air/fuel mixture. In the top of the cylinder, in the cylinder head is a spark plug, which ignites the compressed air/fuel mixture. The mixture explodes and forces the piston back down the cylinder. The piston is connected to a shaft, called the crank, which is connected to the car's transmission, which is connected to the car's drive wheels. When the piston is forced down by the exploding air/fuel mixture it forces the crank to turn, which turns the transmission, which turns the wheels. Without the gasoline, there would be nothing make the explosion which drives the car. Look at the linked page for a more in depth explanation of how an engine works.
the purpose is to ignite the fuel /air mixture at such a time that the resulting burn causes expansions of the gases which forces the piston down and so turns the crankshaft.
The four-stroke cycle consists of four distinct strokes: intake, compression, power, and exhaust. During the intake stroke, the piston moves down, drawing in a mixture of air and fuel. In the compression stroke, the piston moves up, compressing this mixture before the spark plug ignites it during the power stroke, which forces the piston down. Finally, in the exhaust stroke, the piston moves back up to expel the burnt gases from the cylinder.
If there is oil getting to the top of the piston and burning then you have a blown head gasket or the piston rings are worn or broken. Engine must be disassembled.
The expanding high-pressure gases from combustion push the piston down the cylinder during the power stroke in an internal combustion engine. This force generated by the burning fuel drives the piston down, converting the pressure and heat energy into mechanical energy to rotate the engine's crankshaft.
The fuel/air mixture is compressed by the piston moving upwards, the spark plug ignites that mixture and causes an explosion which pushes the piston downward.