When it comes to the performance and efficiency of a car’s engine, there are various mechanical operations that play a crucial role. One such operation is the firing order, which determines the sequence in which the cylinders ignite and generate power. In the case of GM’s Chevy Generation III and IV small block engines, commonly referred to as LS engines, the firing order is unique and contributes to their exceptional performance. In this article, we will delve into the details of the LS engine firing order and cylinder numbers, shedding light on what makes these engines stand out among others.
The LS Engine Firing Order and Cylinder Numbers
The LS engines, denoted by the acronym “Luxury Sport” and belonging to the third and fourth generations of V8 engines with small blocks, were prominently featured in General Motors’ Chevrolet vehicles. The first LS engine was introduced in the Chevrolet Corvette C5 in 1997, marking the beginning of a remarkable lineage.
The firing order of an engine determines the power output, torque, cooling, and overall smooth running of the engine. It represents the sequence in which the internal cylinders of a vehicle’s engine ignite during the power generation process. In the case of LS engines, the firing order was upgraded from the traditional Chevrolet small block/big block engines’ 1-8-4-3-6-5-7-2 order to the more efficient 1-8-7-2-6-5-4-3 order. However, it is possible to upgrade the firing order of older Chevy engines to match that of LS engines with the assistance of an expert auto technician.
The LS engines’ firing order is directly connected to the cylinder numbering system. GM designed the LS engines with four cylinders on each side (left and right) of the engine block, making them V8 engines. This arrangement, known as the “fold method” of cylinder numbering, is widely used throughout the automotive industry. To determine the cylinder numbers in an LS engine, one needs to stand directly opposite the car and observe the engine block. The driver’s side of the engine carries cylinders 1-3-5-7, while the passenger’s side houses cylinders 2-4-6-8. Cylinder 1 and cylinder 2 are closest to the observer, while cylinders 7 and 8 are situated at the farthest end of the engine block.
LS Engine Variants and Their Firing Orders
Now let’s delve into the firing orders and cylinder numbers of some popular LS engine variants:
- 4.8 LS Engine Overview:
The 4.8L LS engine, also known as the 4.8L Vortec or Vortec 4800, was featured in vehicles such as the Chevy Silverado 1500 and the Chevy Tahoe. The firing order of the 4.8 LS engine follows the standard LS pattern: 1-8-7-2-6-5-4-3. In terms of cylinder numbering, cylinders 1, 3, 5, and 7 are located on the driver’s side, while cylinders 2, 4, 6, and 8 are positioned on the passenger’s side. - 5.3 LS Engine Overview:
The 5.3 LS engine, also known as Vortec 5300, was widely used between 1999 and 2007. It offered compatibility with various upgrade system kits and shared the same firing order as the 4.8 LS engine: 1-8-7-2-6-5-4-3. Similarly, cylinder numbering follows the fold method, with cylinders 1, 3, 5, and 7 on the driver’s side and cylinders 2, 4, 6, and 8 on the passenger’s side. - 5.7 LS Engine Overview:
The 5.7L LS engine, featured in high-performance GM cars like Camaro, Corvette, Firebird/Trans Am, CTS-V, and GTO, maintained the same firing order as the 5.3 LS engine: 1-8-7-2-6-5-4-3. In terms of cylinder numbering, the even-numbered cylinders (2, 4, 6, 8) are located on the passenger’s side, while the odd-numbered cylinders (1, 3, 5, 7) are situated on the driver’s side. - 6.0 LS Engine Overview:
The 6.0L LS engine, known as Vortec 6000, found its place in various Chevrolet models, including the Silverado 2500, Suburban, Express, Silverado 1500HD, and Silverado 3500. It shares the same firing order as other LS engines: 1-8-7-2-6-5-4-3.
