LS firing order is a crucial aspect of engine performance. It refers to the sequence in which internal engine cylinders are ignited to produce power.
The firing order plays a critical role in the overall performance of the engine, affecting everything from power output to fuel efficiency.
The LS engine is a popular engine platform used in a wide range of applications, from high-performance sports cars to heavy-duty trucks.
The LS engine is known for its reliability, power, and versatility. Understanding the LS firing order is essential for anyone who wants to tune or modify their LS engine for maximum performance.
Whether you are a professional mechanic or a DIY enthusiast, understanding the LS firing order is essential for maintaining the engine’s performance and ensuring optimal power output.
By understanding the firing order, you can diagnose engine problems, improve fuel efficiency, and fine-tune the engine for maximum performance.
Understanding LS Firing Order
The firing order of an engine refers to the sequence in which the power event happens in different cylinders. For LS engines, the firing order is 1-8-7-2-6-5-4-3. This firing order is a cross-plane driving rod that is equally divided by 90°, which means that the firing of the cylinders is evenly distributed across the engine.
The LS firing order is different from the firing order of other engines. For example, the firing order for a Gen I small-block engine is 1-8-4-3-6-5-7-2. Notice that cylinders 4 and 7 have swapped, and cylinders 3 and 2 have swapped. However, the LS engine firing order is 1-8-7-2-6-5-4-3, where cylinders 4 and 7, and 3 and 2 are in their original firing order positions.
The LS firing order is designed to provide a smooth and efficient power delivery, and it does a decent job of alternating firing between banks as much as possible. However, some LS engine enthusiasts have experimented with different firing order combinations, such as the 4/7 swap.
This modification switches the firing order of cylinders 4 and 7, which can improve low-end torque and reduce vibration.
It’s important to note that changing the firing order of an LS engine requires modifications to the camshaft, crankshaft, and timing chain. It’s not a simple modification and should only be attempted by experienced mechanics or engine builders.
In summary, the LS firing order is 1-8-7-2-6-5-4-3, and it provides a smooth and efficient power delivery. While some LS enthusiasts have experimented with different firing order combinations, it’s important to understand that this modification requires significant engine modifications and should only be attempted by experienced mechanics.
The LS Engine Series
The LS engine series is a family of V8 engines produced by General Motors (GM) under the Chevrolet brand. The LS engines are an improvement over the revolutionary Chevy 350 Small Block Engine and are known for their unique technical specifications in the horsepower and torque categories.
The LS engines were first introduced in 1997 with the Gen III series, which included engines such as the LS1, LS6, LR4, and LM7. These engines were used in popular models such as the Camaro and Corvette. The Gen III engines were produced until 2007, when they were replaced by the Gen IV series.
The Gen IV LS engines were produced from 2005 to 2017 and included engines such as the LS2, LS7, and Vortec 4800. These engines were known for their improved performance and fuel efficiency. The LS engines were also used in trucks and SUVs, making them a versatile choice for consumers.
In 2014, GM introduced the Gen V LS engines, which included engines such as the LT1 and LT4. These engines were known for their advanced technology, including direct injection and variable valve timing. The Gen V engines were used in models such as the Corvette and Camaro.
Overall, the LS engine series has been a popular choice for consumers due to its reliability, performance, and versatility. The LS engines have become a staple in the automotive industry and have helped to establish GM as a leader in engine technology.
Cylinder Numbering and Banks
The LS engine uses a unique cylinder numbering system that can be confusing for those unfamiliar with it. The numbering system starts with cylinder number one on the driver’s side and continues in sequence to cylinder number eight on the passenger side. This means that cylinders one, three, five, and seven are on the driver’s side, while cylinders two, four, six, and eight are on the passenger side.
The cylinders are also divided into two banks, Bank 1 and Bank 2. Bank 1 includes cylinders one, three, five, and seven, while Bank 2 includes cylinders two, four, six, and eight. The firing order for the LS engine is 1-8-7-2-6-5-4-3, which is different from the traditional small-block Chevy firing order.
The cylinder numbering system is important because it affects how the engine is timed and how the spark plugs are installed. It is also important to note that the LS engine uses a different firing order than traditional small-block Chevy engines. This means that the spark plug wires must be installed in the correct order to ensure proper engine operation.
In addition to the cylinder numbering system, the LS engine also has a unique bank angle. The engine has a 90-degree bank angle, which means that the cylinders are arranged in a V-shape with a 90-degree angle between the two banks. This is different from other V8 engines that may have different bank angles.
Understanding the cylinder numbering and bank system is important when working on an LS engine. It is essential to ensure that the spark plug wires are installed correctly and that the engine is timed properly. By following the correct cylinder numbering and bank system, the LS engine can operate at peak performance, delivering the power and torque that it is known for.
Crankshafts and Camshafts
The LS engine’s firing order is determined by its crankshaft design. The LS engine uses a 1-8-7-2-6-5-4-3 firing order, which is different from the traditional 1-8-4-3-6-5-7-2 firing order used in most V8 engines. The LS engine’s firing order is optimized for performance and efficiency, and it is achieved by using a different crankshaft design.
The LS engine uses a cross-plane crankshaft, which is different from the flat-plane crankshaft used in some other high-performance engines. A cross-plane crankshaft has four throws that are spaced at 90-degree intervals, and it is designed to provide a smooth idle and good low-end torque.
The flat-plane crankshaft, on the other hand, has two throws that are spaced at 180-degree intervals, and it is designed to provide better high-end horsepower.
The LS engine’s cross-plane crankshaft is designed to provide a firing order that is optimized for performance and efficiency. The crankshaft rotates twice for every complete cycle of firing, which means that each cylinder fires once every two crankshaft rotations. This firing order is achieved by using a specific camshaft design that is timed to the crankshaft rotation.
The camshaft is responsible for opening and closing the engine’s valves, which allows air and fuel to enter the combustion chamber and exhaust gases to exit. The camshaft is timed to the crankshaft rotation, and it is designed to provide the correct valve timing for each cylinder.
The LS engine’s camshaft is designed to provide a firing order that is optimized for performance and efficiency, and it is timed to the crankshaft rotation to achieve this goal.
In summary, the LS engine’s firing order is determined by its crankshaft design, which is optimized for performance and efficiency. The cross-plane crankshaft is designed to provide a smooth idle and good low-end torque, and it is timed to the camshaft to provide the correct firing order.
The camshaft is responsible for opening and closing the engine’s valves, and it is timed to the crankshaft rotation to provide the correct valve timing for each cylinder.
Power and Performance
The LS engine family has been a favorite among engine builders and performance enthusiasts for its high power output potential. The LS firing order was changed to 1-8-7-2-6-5-4-3 to enhance power [^1]. This firing order does an excellent job of alternating firing between the banks as much as possible, which helps to reduce load and increase horsepower.
LS engines are known for their ability to handle nitrous oxide, superchargers, and turbos. They can handle large loads of nitrous oxide without any issues, and the supercharger and turbochargers can produce massive amounts of power when tuned correctly.
One popular modification to the LS firing order is the 4/7 swap, which switches the firing order of cylinders 4 and 7 [^2]. The 4-7 swap can help to reduce load and increase horsepower, making it a popular modification among LS engine enthusiasts.
LS engines are also known for their ability to handle high-performance applications. They are commonly used in drag racing, road racing, and other high-performance applications. The LS engine’s high power output potential and ability to handle large loads make it a favorite among engine builders and performance enthusiasts.
In conclusion, the LS engine family is a high-performance engine that can handle nitrous oxide, superchargers, turbos, and other high-performance applications. The LS firing order was changed to enhance power, and the 4/7 swap is a popular modification that can help to increase horsepower and reduce load.
Engine Components
LS engines are known for their reliability and performance, which is why they are a popular choice for many car enthusiasts. To understand the LS firing order, it’s essential to have a basic understanding of the engine components that make it all possible.
Cylinder Heads
The cylinder heads are a crucial component of the LS engine. They house the valves, which control the flow of air and fuel into the combustion chamber. LS engines have a unique head design that allows for better airflow and increased power.
Cooling
Proper cooling is essential to keep an LS engine running smoothly. LS engines use a water-cooled system to regulate engine temperature. The cooling system includes a radiator, water pump, and thermostat.
Spark Plugs
Spark plugs are responsible for igniting the fuel and air mixture in the combustion chamber. LS engines use high-performance spark plugs that can withstand high temperatures and pressures.
Injector
The fuel injector is responsible for delivering fuel to the combustion chamber. LS engines use a high-pressure fuel system that delivers fuel to the injectors at a rate of up to 3,000 psi.
Rod Bearings
Rod bearings are crucial to the LS engine’s longevity. They connect the connecting rod to the crankshaft and help reduce friction between the two components. LS engines use high-quality bearings that can withstand high RPMs and loads.
Intake System
The intake system is responsible for delivering air to the combustion chamber. LS engines use a high-flow intake system that allows for better airflow and increased power. The intake system includes an air filter, intake manifold, and throttle body.
Engine Builder
LS engines are known for their reliability, but proper assembly is crucial to ensure they perform at their best. It’s essential to have an experienced engine builder assemble the engine to ensure all components are installed correctly.
Gas
LS engines can run on both regular and premium gasoline. However, using premium gasoline can help increase power and performance.
Overall, the LS engine is a reliable and high-performance engine that has become a popular choice for car enthusiasts. Understanding the engine components is essential to ensure the engine runs smoothly and performs at its best.
Understanding LS Variants
LS engines are a family of engines developed by General Motors and are considered some of the most powerful engines in the world. They are known for their high performance, reliability, and versatility. LS engines come in different variants, each with its unique specifications, features, and firing order.
One of the earliest LS engines is the Gen I small-block engine. This engine was introduced in the 1950s and was used in various GM vehicles. The Gen I engine has a firing order of 1-8-4-3-6-5-7-2, which is different from the firing order of LS engines.
Another popular engine is the LT1, which was introduced in the early 1990s. The LT1 engine has a firing order of 1-8-7-2-6-5-4-3, which is the same as the firing order of LS engines.
The LS engine family also includes big-block engines (BBC) and small-block engines (SBC). The BBC engines have a firing order of 1-8-4-3-6-5-7-2, while the SBC engines have a firing order of 1-8-4-3-6-5-7-2. The firing order of LS engines is different from both the BBC and SBC engines.
Ford 351w and 5.0 engines also have a different firing order from LS engines. The Ford 351w engine has a firing order of 1-3-7-2-6-5-4-8, while the Ford 5.0 engine has a firing order of 1-5-4-2-6-3-7-8. Buick engines have a firing order of 1-6-5-4-3-2, which is also different from LS engines.
LS engines do not have a distributor, which means that the firing order is determined by the engine control module (ECM). The ECM controls the spark timing and ensures that the spark plugs ignite in the correct order. This eliminates the need for a distributor and provides a more efficient ignition system.
Internal Combustion Process
The internal combustion process is the heart of any engine, including V8 engines. It is the process that converts fuel into energy that powers the engine. In an internal combustion engine, fuel is burned inside the engine to produce power. This process involves four basic steps: intake, compression, combustion, and exhaust.
During the intake stroke, the piston moves down the cylinder, creating a vacuum that draws air and fuel into the combustion chamber. The air and fuel mixture is then compressed during the compression stroke, which increases the temperature and pressure inside the combustion chamber.
Next, the spark plug ignites the air and fuel mixture, causing a rapid expansion of gases that pushes the piston down the cylinder, producing power. This is the combustion stroke, and it is the most important step in the internal combustion process.
Finally, during the exhaust stroke, the piston moves up the cylinder, forcing the spent gases out of the engine through the exhaust valve.
The firing order of an engine is the sequence in which the cylinders fire. For V8 engines, the firing order is usually 1-8-4-3-6-5-7-2 or 1-3-7-2-6-5-4-8. The firing order is important because it affects the balance and smoothness of the engine.
To Summarize
In summary, LS engines are V8 engines with eight cylinders and a single crankshaft. The firing order is the sequence in which the spark plugs ignite in each cylinder to push the pistons in a particular order. The firing order for LS series engines is 1-8-7-2-6-5-4-3.
Changing the firing order of an LS engine can be done by modifying the PCM/ECM. However, it is important to note that changing the firing order can affect the engine’s performance and should only be done by experienced mechanics.
Additionally, it is important to note that there is a popular modification called the “4/7 swap” that switches the firing order of cylinders 4 and 7. This modification can improve engine performance by reducing exhaust overlap and increasing low-end torque.
Overall, understanding the firing order of LS engines is crucial for maintaining and improving engine performance. Experienced mechanics should be consulted for any modifications to the firing order.
![Read more about the article 5.7 Hemi Problems [7 Most Common]](https://roadsumo.com/wp-content/uploads/2021/11/5.7-Hemi-Problems-300x200.jpg)