Chevy 350 5.7 Firing Order 1-8-4-3-6-5-7-2 Small-Block & V8 Big Block (2024)

As an enthusiast of Chevy engines, I’ve learned that a deep understanding of the firing order is crucial. This knowledge is especially important for anyone dealing with a rebuilt or replaced engine. Remember, each Chevy 350 engine has its own specific firing sequence and I will discuss Chevy 350 5.7 firing order in this article .

If this sequence is incorrect, you might face a bumpy and uncomfortable ride, marked by misfiring and poor running performance. Knowing the precise firing order ensures your engine functions properly, offering a smooth ride every time.

Understanding the firing order diagram is crucial for anyone dealing with a rebuilt or replaced Chevy 350 5.7 engine. An incorrect firing sequence can lead to misfiring and poor running performance. Ensure your engine functions properly by knowing the precise firing order, which will provide a smooth ride every time.

Firing Order for the Chevy 5.3 L V8 Engine Big Block

The Chevy 5.3 L V8 Big Block, a popular choice in the automotive market, represents a significant evolution from the 350 Chevy and other small-block engines like the 262 Chevy, 302 Chevy, and 327 Chevy. Chevy 350 5.3 liter firing order is 1,8,7,2,6,5,4,3, plays a pivotal role in its performance and efficiency.

1. Unique Firing Sequence: The 5.3L V8 engine’s firing order differs from Chevy 350’s traditional sequence and even from other V8 engines like the 396, 427, and 454 Big Block.
2. Cylinder Numbering and Placement: The engine’s cylinders are numbered in a staggered sequence from side-to-side, starting with the #1 cylinder on the driver’s side for rear-wheel drive cars.
3. Cross-Plane Crankshaft Design: The 5.3 L V8 utilizes a cross-plane crankshaft with throws spaced 90 degrees apart, which is standard in many Chevy vehicles, including minivans and trucks.
4. Clockwise Spark Plug Firing: The spark plugs fire in a clockwise direction, as determined by the firing order, ensuring efficient power distribution.
5. HEI Distributor Cap Configuration: The HEI distributor cap used in these engines has terminals arranged to support this firing sequence.
6. Routine Maintenance for Performance: Regular maintenance, including replacing spark plugs and wiring, is crucial to avoid poor performance or stalling.
7. Comparison with LS Engines: Unlike the 5.3L V8, the Chevy LS engines (LS1 to LS7) follow a different firing order (1-8-7-2-6-5-4-3), which impacts their performance and fuel efficiency.
8. Front Cylinder Identification: In these engines, the front-left cylinder is always number 1, a key factor in identifying the firing order.
9. Alternating Cylinder Numbering: The odd-numbered cylinders are located on the driver’s side, while the even-numbered cylinders are on the passenger’s side.
10. Importance of Correct Wiring: Ensuring wires and plugs are correctly connected according to the firing order is vital for the engine to run smoothly.
11. Vehicle Compatibility and Mounting: This firing order and engine design are compatible with various Chevy models, including both front-wheel and rear-wheel drive configurations, with adjustments for transverse or sideways mounted engines in minivans.

The Chevy 5.3 L V8 Big Block engine’s firing order significantly differs from that of small-block engines like the 350 Chevy. This sequence is vital for smooth operation and optimal performance, highlighting the importance of correct installation and regular maintenance.

Chevy 350 Firing Order (Small Block)

Small-block engine, earning its nickname “SBC” for being notably more compact than big-block crate engines. The Chevy 350 firing order is a crucial aspect of the small-block engine’s performance. Known for its compact size compared to the big-block (BBC), the Chevy 350 (SBC) maintains a consistent firing order across various models, ensuring smooth and efficient engine operation.

• Uniform Firing Sequence: The 1-8-4-3-6-5-7-2 firing order is uniform across Chevy 350 small-block engines, including 262, 265, 267, 283, 302, 305, 307, 327, 350 (5.7 vortec), and 400 Chevy. This sequence ensures each cylinder fires effectively for optimal performance.
• Cylinder Identification and Placement: Identifying the number one cylinder is key; it’s located at the front-left of the engine on the driver’s side. Odd-numbered cylinders are on the driver’s side, and even-numbered on the passenger’s side.
• Distributor Cap and Spark Plugs: The distributor cap has valves in the center with cylinders labeled on the edges. The inner circle indicates the spark plug for each cylinder, aiding in correct spark plug placement.
• Importance of Correct Timing: Proper timing and maintaining the firing order are essential for engine health and to prevent performance risks.
• Chevy V8 Engine Comparison: This firing order applies to small-block Chevy engines, excluding LS1 to LS7 engines, which run on a 1-8-7-2-6-5-4-3 order, similar to the 5.3L engine but different from other Chevy vehicles with small-block motors.

The Chevy 350’s firing order is fundamental to its efficiency and power output. Understanding and maintaining this order is essential for the longevity and optimal performance of these iconic engines.

What does Firing Order Mean?

Firing Order is the sequence in which the spark plug in each cylinder fires during the operating cycle. For the Chevy 350, this order is 1-8-4-3-6-5-7-2, a correct and tightly regulated pattern ensuring smooth operation. Each spark plug follows the next in a clockwise direction, starting from the distributor cap. This not only balances the engine but also reduces vibrations for a better ride. When setting the timing, it’s key to align the rotor inside the distributor with the terminal for the number one spark plug. This occurs when the piston is at top dead center (TDC) on the compression stroke. Understanding and adjusting this firing order is beneficial for the proper operation of the engine’s systems, ensuring your Chevy 350 works effectively.

Why Firing Order Matters?

Firing order in a Chevy 350 is crucial for optimal engine performance. A correct firing order maintains balance and ensures smooth operation. Misplaced wires can cause misfiring, backfire, or prevent the engine from starting.

1. Correct Sequence Necessity: The firing order is essential for engine efficiency, ensuring cylinders fire quickly and in the right sequence.
2. Electrical Interference Management: Ignition Crossfire, a risk in engines with adjacent cylinders, can be prevented by properly routing spark plug wires to cancel magnetic induction.
3. Engine Computer Control: In distributor-less and coil-on-plug systems, the firing order is controlled by the engine computer, using inputs from crankshaft and camshaft position sensors.
4. Even and Odd Firing: Even firing orders alternate in pairs (e.g., 1 & 2, 3 & 4), while odd firing orders alternate between non-adjacent cylinders.
5. Vibration Reduction: A well-managed firing order significantly reduces engine vibrations, enhancing the vehicle’s performance.
6. Turbocharged/Supercharged Balance: In turbocharged or supercharged engines, firing order is key to balancing pressure from each combustion cycle.
7. Performance and Pressure Management: Firing order directly influences performance and manages the pressure in cylinders during the combustion cycle.
8. Front to Back Cylinder Numbering: In small V-type engines, cylinders are typically numbered 1 through 4 (or more) from front to back.
9. Engine Block Information: The firing order is often printed on or near the engine block, though it may require searching in some cases.
10. Importance in Starting and Running: The correct firing order is vital for the engine to start and run properly.
11. Preventing Engine Misfires: Proper firing order helps avoid premature firing of spark plugs, thereby preventing engine misfires.
12. Optimizing Engine Systems: A correct firing order is necessary for the proper operation of the engine’s systems.

In essence, the firing order of an engine is integral to its health and efficiency. Understanding and correctly implementing it can mean the difference between a well-functioning engine and one prone to problems.

Changing the Firing Order

With GM BB and SB V8 engines, including the Chevy 350, the firing order is not set in stone. With special racing cams, such as the 4-7 swap cam, it’s possible to change the firing order. This modifying technique swaps the firing order of cylinders 4 and 7, resulting in a new firing order of 1-8-7-3-6-5-4-2. The 4-7 swap is more than a mere adjustment; it improves the air/fuel distribution, particularly between cylinders 4 and 7. This modification makes the engine easier to tune and reduces heat buildup at the back of the engine. Additionally, it reduces torsional loads and vibrations on the crankshaft, enhancing the engine’s overall performance and longevity. Such changes underscore the versatility and adaptability of Chevy’s engines, demonstrating how even small alterations can yield significant improvements.

What Happens if the Firing Order is Out of Order?

An incorrect firing order in a Chevy 350 engine can lead to various issues. It’s not just about the engine failing to start; it affects the overall performance and health of the engine.

1. Misfiring and Poor Performance: When wires are mixed up, the engine may misfire or run poorly, leading to noticeable reductions in power output.
2. Backfiring Issues: Incorrect routing of spark plug wires can cause the engine to backfire.
3. Starting Difficulties: A displaced firing order might prevent the engine from starting at all.
4. Increased Wear and Damage: Misrouting wires can cause uneven stress on the crankshaft and connecting rods, leading to premature wear and potential damage to internal components.
5. Costly Repairs and Damage: Not following manufacturer’s guidelines and adjusting the firing order incorrectly can result in costly repairs and damage to the engine.
6. Cylinder Sequence Importance: Each cylinder must receive its fuel/air mixture at the right time to ensure proper combustion.
7. Check and Adjustment: If you suspect an issue, check the firing order and adjust according to the service manual or seek assistance from a repair shop.
8. Use of Genuine Parts: For repairs, always use genuine replacement parts to avoid further issues.
9. Rotating the Crankshaft: If a mistake is made, it’s essential to hand rotate the crankshaft to align the timing mark with the Top Dead Center (TDC) indicator.
10. Evaluating Engine Design: Understanding that different engines have different firing orders based on their purpose and design features is crucial.
11. Following Specified Firing Orders: Ensuring correct and specified firing orders for each engine type.
12. Avoiding Misrouting: Care must be taken to not mix up the wiring, especially in older engines with a distributor.

The correct firing order is essential for the smooth operation and longevity of your Chevy 350. Neglecting this can lead to significant performance issues and engine damage, emphasizing the need for careful maintenance and using quality parts.

Key Takeaways – Chevy 350 5.7 Firing Order

The firing order of the Chevy 350 and its 5.3 and 5.7 engines, encompassing both small block and V8 big block versions, is fundamental for engine efficiency and performance. In these engines, the firing order—1-8-4-3-6-5-7-2—ensures smooth operation and is crucial for optimal engine performance.

• Uniform Firing Sequence: Across all Chevy 350 small block V8 engines, the firing order remains consistent at 1-8-4-3-6-5-7-2.
• Cylinder Arrangement: Cylinder 1 is located on the left side (driver’s side) of the engine, with odd numbered cylinders on this side and even cylinders on the right side (passenger’s side).
• Early Chevy V8 Engines: This firing order helps in improving air/fuel distribution, particularly crucial in carbureted or TBI non-IR intake systems.
• Late Model LS Engines: Engines like the LS1/LS6 and Vortec truck engines (4.8, 5.3, 6.0, 8.1 liters) use a revised firing order of 1-8-7-2-6-5-4-3 to enhance smoothness and resolve fuel distribution issues.
• Racing Cam Adaptations: Reher-Morrison’s racing cams, custom ground by Erson for big blocks, modify the firing order to 1-8-7-3-6-5-4-2, a common configuration in Pro Stock engines.
• Correct Installation and Labeling: Properly labeling the distributor cap and spark plug ends is essential for ensuring the correct firing order.

The knowledge of the firing order is not just a technical detail but a pivotal aspect that impacts the engine’s performance, fuel efficiency, and emission control. For anyone working on these engines, understanding and maintaining the correct firing order is key to ensuring their longevity and peak performance.

Frequently Asked Questions (FAQs):

What is the firing order of the 5.7 V8?

The firing order for the 5.7 V8 is 1-8-4-3-6-5-7-2.

What is the firing order on a 1990 Chevy 5.7 L?

For a 1990 Chevy 5.7 L, the firing order is 1-8-4-3-6-5-7-2.

What is the firing order on a 93 5.7 L?

The firing order for a 93 5.7 L is 1-8-4-3-6-5-7-2.

What is the firing order for a Chevy clockwise?

The Chevy’s firing order in a clockwise rotation is 1-8-4-3-6-5-7-2.

What is the ignition order on a 350?

The ignition order on a 350 Chevy is 1-8-4-3-6-5-7-2.

What is the correct firing order?

The correct firing order for a Chevy 350 is 1-8-4-3-6-5-7-2.