5.7 Vortec Firing Order (Cylinder Numbers with Diagram)

If you are a mechanic or a petrolhead, you know how crucial knowing the engine firing order can be. If you are not familiar with the concept, it is simply the order in which each cylinder in your engine fires when you start it up.

This is important because knowing your Vortec’s firing order will help diagnose problems with your engine, such as misfires and engine vibrations issues.

In this article I am going to talk about the correct cylinder firing order for a 5.7 Vortec Engine. Let’s Dive in!

5.7 Vortec Firing Order

Table of Contents

In short, the 5.7 Vortec firing order is s 1-8-4-3-6-5-7-2 which means the first cylinder that fires is 1 followed by 8 then 4 and so on until the last cylinder which is 2.

This is the sequence in which the cylinders in the engine are ignited. This order is used to reduce crankshaft torsional shake. It is important to maintain the correct firing order in order to ensure engine performance and efficiency.

About Chevy 5.7 Vortec Engine

The Chevy 5.7 Vortec engine is a type of V8 engine produced by General Motors. It is known for its excellent performance and its horsepower rating is around 255 with a 335 torque.

This small block engine is known for its flexibility and reliability when it comes to improving performance and overall lifespan.

For example it can easily be upgraded by using KN which raises the horsepower by 45 percent and has a technical specification of no filter cleaning required for up to 100,000 miles.

The 5.7 Vortec is often compared to its sibling the 5.3 L Vortec engine which is rated at 270 horsepower and 315 torque, with its maximum output is 320 horsepower and 335 lb.-ft of torque.

Both have their own pros and cons, now let us get to the firing order for this engine.

Chevy 5.7 Vortec Firing Order Diagram

The Importance of Firing Order on a Vortec Engine

Now, that you know the correct firing order, let’s look at why this is critical for the engine.

The firing order is important because it determines the timing of when each spark plug fires and when each fuel injector opens.

This in turn controls the power, efficiency and smoothness of the engine. A misfire in the firing order can cause a rough idle, poor fuel economy, and reduced power. In some cases, it can even cause engine damage.

The sequence at which cylinder fires in an engine has a direct impact on the performance of an engine.

If one or two cylinders misfires or the firing order is incorrect then the engine will not run as smoothly or efficiently as it should. The engine may also run poorly or stall.

5.7 Vortec Firing Order Table

Cylinder Number	Firing Order
1	1
2	8
3	4
4	3
5	6
6	5
7	7
8	2

How Can You Tell if Your 5.7 Vortec Firing Order is Correct?

If you suspect that your firing order is incorrect, there are several ways to tell. Here are the few main signs of wrong firing order:

Engine Unusual Vibrations
Rough Idling
Poor Average Fuel Economy
Engine Misfire
Throttle response lag
Loss of Power

Another way I recommend is to check for engine codes using an OBD-II scanner. If the engine is misfiring, the scanner will display the specific cylinder that is misfiring. You can also check the engine’s compression, which can be done by performing a compression test.