” Firing order” is a very popular phrase used in the mechanic and engine world. Many people mention it though not all know the meaning of how it works. Every engine model has a different firing order. For example, all Cat engines do not use the same firing order. So in this article, I will focus on the firing order of 3406.
There are varieties of 3406; 3406A, 3406B, 3406C, and 3406C. The four of them are using the same firing other.
The firing order for the Caterpillar 3406 Engine is 1-5-3-6-2-4.
What is a firing order? Firing order is the order in which fuel is injected into each cylinder of the engine by the engine timing.
It is the sequence in which the injection pump follows to inject fuel to combust the compressed air in order to produce power.
In a simple word, it means when cylinder #1 receives fuel, the next cylinder to receive is cylinder #5, followed by #3, #6, #2, and #4. These are the sequences in which fuel is supplied to the cylinder.
But you could have asked why not 1-2-3-4-5-6? If it is like that then the engine is going to be vibrating, have irregular sound, and have poor engine performance. No wonder if you use the wrong firing order, you will notice the engine will be misfiring, have increased noise and also poor performance. This can happen if you misplace the sequence of the injection pressure pipe, especially in the rotary injection pump.
The firing order is also useful when adjusting the valve lashes. Although there are many methods of adjusting valve lashes, using the firing order is one of the most accurate methods you can use.
However, you should know that firing order is different from engine numbering. The 3406 engine numbering is 1-2-3-4-5-6. You start counting the front of the engine which is from the radiator or the timing cover.
You should also know that the firing order is still different from companion cylinders.
Companion cylinders are two cylinders that are always at the same piston position in the cylinder but at a different stroke.
In a 3406, the companion cylinders are; 1&6, 2&5, 3&4. Looking at the number you can see that it is very different from the firing order.
So the firing order helps the engine to avoid vibration, imbalance, backfiring, and misfiring.
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