straightfours

A straight-four, also known as an inline-four, is an internal combustion engine configuration with all four cylinders in a straight line. This configuration is widely used in a variety of vehicles, from small cars to motorcycles. The cylinders are typically arranged in a single bank, firing in a specific sequence to produce smooth power. The relatively simple design and compact size make it an economical choice for manufacturers.

The firing order of a straight-four engine is crucial for its operation. A common firing order is 1-3-4-2, meaning the cylinders fire in this sequence. This order helps to balance the engine's forces, reducing vibrations. Straight-four engines can be either gasoline-powered or diesel-powered. They are known for their good fuel efficiency and affordability to produce.

However, straight-four engines can experience vibrations, especially at higher revolutions per minute, due to inherent imbalances in the reciprocating masses of the pistons and connecting rods. Counter-rotating balance shafts are sometimes employed in larger or more performance-oriented straight-four engines to mitigate these vibrations. Despite these potential drawbacks, the straight-four remains a popular and practical engine choice for a vast range of applications.