Straight-four engines typically use a firing order of 1-3-4-2, however some British engines used a firing order of 1-2-4-3. Flat-four engines typically use a firing order of R1-R2-L1-L2. Straight-five engines typically use a firing order of 1-2-4-5-3, in order to minimise the primary vibration from the rocking couple.

What is the firing order of an inline 4 cylinder engine?

Most 4-cylinder engines have a firing order of 1-3-4-2 although other firing orders such as 1-3-2-4, 1-4-3-2, 1-2-4-3 are possible. Consider the inline 4 engine in Figure 1.

Why is the firing order not 1234?

Most straight 4 cylinder engines use the 1-3-4-2 configuration. So why, according to wikipedia, 1-4-2-3 was never implemented in any straight 4 cylinder engines? The cylinders firing are even further apart than the one currently used. 1-2-4-3 is essentially the same as 1-4-2-3.