BBC 396 Firing Order: Delving into the Heart of the Iconic 396 Engine

By Nick Marchenko, PhD

In the realm of American muscle cars and high-performance engines, the big block Chevy 396 holds a special place. Known for its robust power output and iconic design, this engine has fascinated automotive enthusiasts for decades.

One key aspect of an engine's performance lies in its firing order. In this article, we will delve into the firing order of the big block Chevy 396, shedding light on this crucial element of its operation.

BBC 396 engine

The Chevrolet 396 CID big block engine's fate was sealed many years ago. In 1970, the engine underwent a transformation with its displacement increased to 402 CID.

A few years later, however, General Motors decided to stop making these smaller big block engines for both automobiles and trucks. GM's continuous use of the term "396 big block," which only served to exacerbate the already pervasive uncertainty in the big block market, was one aspect that may have led to the engine's downfall.

Following its official retirement, the 396 will forever be remembered as the runner-up to the mighty 454 big block. With the introduction of newer and larger displacement engines like GM's 8.1 liter 496 CID truck engine, the humble 396 was pushed further into the realms of big block obscurity.

Shop From Amazon

ACDelco GM Original Equipment 41-114 Iridium Spark Plug (Pack of 1)

A-Premium High Heat Spark Plug Ignition Wires Set of 8 Compatible with Chevrolet Chevy GMC...

8 AD Auto Parts Ignition Coils + 8 OEM 41-962 Double Platinum Spark Plugs + 8 Herko WGM48...

Without delving into intricate details about production figures and years of availability, it is safe to say that more 396 CID big blocks found their way into cars than the combined numbers of 427 and 454.

However, the 396 is often overlooked by the performance community, which tends to adhere to the motto: "If you are going big block, go as big as possible." While this is undoubtedly a sound principle, it is also one that can strain the budget.

The consequence of the 396's relative obscurity has been a reduction in the cost of its components. For instance, a forged GM crank for a 454 engine might cost as much as $400 today, while a forged 396 crank can be found for approximately $75. A rebuildable 396 short block is typically priced at less than $200 compared to a 454 short block, which could easily cost $500.

The big block Chevy 396 firing order

In an internal combustion engine, the firing order determines the sequence in which each cylinder receives a spark to ignite the air-fuel mixture.

The engine will function effectively and smoothly thanks to this procedure. The firing order is a crucial component of engine design since it influences the engine's sound and general appearance in addition to performance.

The firing order of the big block Chevy 396 is a specific sequence in which the engine's eight cylinders are fired. This sequence is as follows: 1-8-4-3-6-5-7-2.

Shop From Amazon

Hypertech 3000 Max Energy Spectrum Power Programmer with Color Screen

8200 DiabloSport inTune i3

BBK 2545 Coil Spring Isolator Kit - Front - Polyurethane for Ford Mustang

To better understand the engine's firing order, imagine yourself in front of the engine, looking at it from the front. The cylinder closest to the front of the engine is on the driver's side, while the cylinder closest to the front on the passenger's side is cylinder number 8.

The firing sequence then changes: from the driver's side it's 1-8-4-3, and from the passenger's side it's 6-5-7-2. This firing order is designed to balance the engine's power output, reduce vibration, and ensure that it runs efficiently. The specific sequence also creates the unique rumble associated with big block Chevy engines, adding to their appeal.

Big block Chevy 4-7 swap

In pursuit of increased ride comfort through modifications to the firing sequence, one popular technique is known as the 4-7 cam swap.

This modification entails exchanging the power stroke of cylinder 4 with that of cylinder 7. Within the big block Chevy engine, the firing order will change from 1-8-4-3-6-5-7-2 to 1-8-7-3-6-5-4-2 as a result of the cam switch. With this modification, the engine will run more smoothly, there will be fewer vibrations, and driving will become more comfortable.

The 4-7 cam swap is widely believed to have a positive impact on engine performance. By reconfiguring the firing sequence, power distribution is made more uniform across the engine's cylinders.

This can contribute to improved balance and reduced stress on certain components, potentially leading to smoother acceleration and enhanced torque output.

Shop From Amazon

Denso 673-1309 Ignition Coil

A-Premium Engine Ignition Coil Packs Compatible with Nissan Altima Rogue Sentra Tiida Vers...

ACCEL 8140 Ignition Coil - Yellow - 42000v 1.4 ohm Primary - Points - Good up to 6500 RPM

It is important to recognize that the suitability of the 4-7 cam swap varies depending on the specific application. It is primarily intended for individuals seeking an upgraded ride comfort experience rather than those aiming for maximum power. Proper installation and precise tuning are imperative to ensure optimal performance and reliability.

Why is the firing order important?

The firing order is more than just a technical detail. It directly influences an engine's performance, smoothness, and sound. It plays a vital role in timing the engine's power strokes and exhaust events, ensuring that all cylinders work in harmony. A proper firing order reduces vibration and enhances engine longevity.

In the case of the big block Chevy 396, the firing order not only contributes to its impressive power but also gives it that distinctive and thunderous exhaust note beloved by enthusiasts.

What is the difference between small block and big block firing order?

The firing order for a big block Chevy engine is the same as for a small block Chevy engine: 1-8-4-3-6-5-7-2. However, the big block Chevy firing order is different from the small block Chevy firing order due to the size differential between these two engine types.

Small block Chevy engines are typically more compact compared to their larger counterparts, the big block Chevy. As a result of this size difference, the firing sequence of the small block Chevy may produce slightly less power but offers enhanced fuel efficiency. Conversely, the firing sequence of the big block Chevy yields greater power output but also consumes more fuel.

Besides size, the primary factor setting these two firing orders apart is the placement of the distributor. A big block Chevy engine's distributor is often located near the back of the engine, whereas a small block Chevy engine's distributor is typically located towards the front of the engine, in addition to their varied diameters.

The firing sequence of the big block Chevy 396, a renowned engine in the world of high-performance cars, is a crucial factor in its exceptional performance and distinct sound.

Understanding the firing order of this iconic engine allows enthusiasts and mechanics to appreciate the engineering that goes into creating a powerful and harmonious powerhouse.

With a firing order of 1-8-4-3-6-5-7-2, the big block Chevy 396 roars to life, exemplifying the perfect blend of engineering and automotive passion that continues to captivate the hearts of those who admire raw American muscle.

Nick Marchenko, PhD

Industrial Engineer & Automotive Content Specialist

Nick writes in-depth guides on car clubs, engine specs, vehicle ownership, and modifications, combining engineering knowledge with automotive passion.

Full profile → LinkedIn →