Want more power under your right foot? Let’s explore the fundamentals of how your engine generates horsepower, applicable whether you’re driving a compact four-cylinder or a powerful V8. Think of it using the simplified principle: Suck, Squeeze, Bang, Blow.
First, the engine “sucks” in oxygen. Air enters through the intake, travels to the manifold, and finally reaches the cylinder chamber. The more air we can get into each cylinder, the better. Oxygen is a critical component for generating horsepower. Maximizing the amount of air in the cylinder during the intake stroke is key.
Next, the “squeeze” phase. After the intake valve closes, the piston moves upward, compressing the air. Simultaneously, fuel is injected into the cylinder. Remembering the fire triangle: air (oxygen), fuel (gasoline), and ignition (spark), compressing the air and fuel creates a highly combustible mixture for the next phase.
Then comes the “bang”. With the air and fuel compressed, the spark plug ignites the mixture, causing a rapid explosion. This explosion forces the piston downward with significant force. This force is the foundation of horsepower. The downward motion of the piston drives the crankshaft, which in turn powers the wheels. The continuous cycle of explosions drives the engine.
Finally, the “blow” phase. The exhaust valve opens, releasing the leftover carbon dioxide and other combustion byproducts from the cylinder. This entire cycle happens incredibly fast, thousands of times per minute, as indicated by your engine’s RPM (revolutions per minute).
That’s the basic overview of how an engine creates power. More articles to follow will cover how to optimize this combustion cycle for maximum horsepower gains.