4 Cylinder Engine Firing Order (PDF) [V4 Explained]

Engines with four pistons in a horizontal line are known as straight-four engines.

There is usually at least one energy stroke on every four-stroke horizontal four, contrasting motors with a smaller number of pistons that don’t have energy strokes at all times. A horizontal engine has just one head gasket relative to a V4 cylinder or a flat-four motor, which minimizes both sophistication and manufacturing costs.

In an internally fired motor, the firing order is the chronology of pistons’ ignitions. The sequence in which the combustion system fires in a spark-ignition motor determines the firing order. In addition to affecting engine noise and turbulence, the firing sequence also has an impact on the engine’s ability to provide power consistently.

Firing Order of 4 Cylinder

  • Firing Order for V4 is 1-3-4-2

Explanation of 4-cylinder firing order diagram 

The firing order of the 4-cylinder engine provides 720 degrees of crankshaft rotation which is known to be a full firing sequence whereas every single piston produces 180 degrees of crankshaft rotation. The auxiliary gears (pulleys) are often positioned in the rear of the motor, where the chambers are typically designated 1234.

Piston 1 will be the valve that’s nearest to the shafts, while Piston 4 will be the valve nearest to the spinning. In a V6 engine, for example, a piston should be ignited every 120 ° depending on Calculation 1. For example, in certain V8 engines and above, producers or motor designers do not always fire pistons at the same time; this is a principle of motor architecture termed unequal firing.

To provide a forceful and croaky engine noise is done. This is very good for the motors with several cylinders. The crankshaft will be under a lot of strain if all the pistons ignite at an identical time. It could perhaps lead to the crankshaft breaking or bending. For a better operation, producers adopt non-sequential firing orders to prevent it.

4 cylinder boxer engine with the firing order of 1 3 4 2 fire before the partner cylinder, A duo of partner pistons raises and lowers together. It is possible to have one piston on the entrance cycle while another is on the exhaust cycle. While one piston is on the compressor cycle, the second is on the emission stroke.

Torque Specifications

Fastener typeFist passSecond pass
Main caps15 ft.-lbs.80 degrees
Cylinder head bolts22 ft.-lbs51 degrees
Rocker arm bolts44 in.-lbs.18 ft.-lbs

Firing Order of 4 Cylinder Engine

Check out Ford 302 Firing Order

How does a 3 differ from 4 cylinder firing order?

The firing order of the 4-cylinder opposes the 3-cylinder engine. In a three-cylinder engine, each of the three crankshafts is positioned 120 degrees away. The arrangement of the pistons of a 3-cylinder motor is 1-3-2, which ensures that the pistons’ strength is evenly distributed.

This is extremely true for engines with several cylinders. The crankshaft will be under a lot of strain if all the pistons ignite at the same time. It could lead to the crankshaft breaking or twisting. For a better operation, designers adopt non-sequential firing sequences to prevent it.

The Firing order applies to 

The firing order of 4 cylinder engine applies to all similar car engines like

  • Honda Accord
  • Chevrolet Malibu
  • Subaru Impreza
  • Hyundai Elantra
  • Subaru WRX STI 305-HP
  • Honda Civic Type R
  • Ford Mustang EcoBoost

What makes the difference between flat 4 and inline-4 engine firing order?

For starters, both an inline-4 and a flat-4 have identical four thrusts: input, pressure, output, and emissions. Nonetheless, the distinctions are immediately obvious. 1, 3, 2, 4, 2 for the flat-4, but for the inline-4, it is 1, 3, 4, 2. The first major change is the firing sequence.

Even though the main and tertiary pressures in each motor are equivalent, the inline-4 and flat-4 engines do not have comparable secondary forces. inline-4 engines, auxiliary forces point outwards when cylinders reach peak or bottom of the cylinders

There are four cylinders in the flat-4 engine that point in opposing directions, balancing off the stresses. So, a flat-4 motor is quieter than an inline-4 because the inline-4 engine lacks a mechanism for distributing energy and hence vibrates more. However, the flat-4 can’t escape brilliance. For some reason, the motor likes to shake across its central line since the cylinders don’t line up precisely.

Diesel engines

Diesel engines have a firing order based on the sequence in which the cylinders receive gasoline injections. Because the cylinders do not release and shut on each stroke, four-stroke motors should also time their cylinder releases about the firing sequence. When designing an engine, the firing sequence is chosen in pattern to maximize efficiency and smoothness.

The crankshaft’s weight and pressure on the cylinders are computed. The weight of the counterbalance has been figured out. The firing sequence is decided by putting all of them into the dynamical balance calculations such that minimum disturbances are created.

The horizontal engine configuration is used by a great number of automobiles with four motors, as well as many motorbikes and other machines. Straight-four cylinders are often referred to as four motors. Liquid cooling is used in the majority of models, although air-cooled ones are also produced.

What is the firing order of the 4-cylinder 2001 Honda Civic?

The 2001 Civic being a 1.6 L engine serves the Cap distribution of a clockwise arrangement with the firing order of  1 3 4 2.

Why does Civic 2002 support a 4-cylinder engine?

A malfunction from one of the four pistons is caused by a lack of one or many of the following. One or more of the above may be happening if your Civic has a malfunction: The CEL  is illuminated.

Why do we exactly need the firing order for a 4-stroke engine?

The 4-cylinder engine works on diesel which includes the revolving cylinder vacuum, decompression, output, and emission in four strokes or four motions of the repeating hammer. When the motor has greater than one chamber, the operation gets more complicated, thus a pre-defined order of ignition or burning of gasoline is necessary.

Higher than one crankshaft means more stress on the crankshaft, which raises the risk of crankshaft breakdown if the right discharge sequence is not delivered to the motor, since all of the cylinders are linked to the same crankshaft. In addition, to maximize performance, efficient running, and long life, the engine’s discharge sequence must be followed precisely.

Explain Engine Firing Order | Automobile Engineering | Video

Jake Mayock