Chevy LS Engine for Cars, Trucks, and VansThe Chevy 350 engine underwent significant changes over the years, with the "pre-LS" and "LS" versions being two distinct engine families. Here are some of the key differences between the two:
- Design: The pre-LS Chevy 350 is an older engine design that dates back to the 1950s, while the LS Chevy 350 is a more modern engine that was introduced in the late 1990s.
- Block: The LS Chevy 350 has an aluminum block, which is lighter and stronger than the cast-iron block used in the pre-LS Chevy 350. The LS block is also more compact and has a better oiling system.
- Cylinder heads: The LS Chevy 350 has a different cylinder head design than the pre-LS version, with better airflow and improved combustion efficiency. The LS heads also have smaller combustion chambers, which increases the engine's compression ratio and improves power output.
- Fuel delivery: The pre-LS Chevy 350 typically uses a carburetor for fuel delivery, while the LS version uses electronic fuel injection (EFI). EFI provides more precise fuel delivery and better fuel efficiency.
- Ignition: The LS Chevy 350 uses a coil-near-plug ignition system, which is more reliable and efficient than the distributor-based ignition system used in the pre-LS version.
Overall, the LS engine is a more advanced and efficient engine than the previous versions, with better performance, fuel economy, and reliability. However, the Chevy 350 has a simpler design and is easier to work on for those who prefer a more hands-on approach to engine maintenance and repair.
Firing Order LS Engine
The firing order of the LS Chevy 350 engine is 1-8-7-2-6-5-4-3. This firing order is the same for all LS-based engines, regardless of the specific displacement.
As for the exhaust manifold, the LS Chevy 350 typically uses a set of tubular headers instead of traditional cast iron exhaust manifolds. These headers are designed to improve exhaust flow and increase horsepower. However, there are many different manufacturers and styles of LS headers available, each with its own specific design and installation requirements. It's important to choose headers that are compatible with your particular engine and exhaust system to ensure proper fitment and performance.
LS Cylinder Cooling is More Advanced
The engine has a more advanced cooling system compared to the Chevy 350 engine. Here are some of the key differences.
- Water jacket design that provides better cooling to the cylinder walls. The water jackets are cast into the block and are positioned closer to the combustion chambers than in the older engine, allowing for more efficient heat transfer.
- Coolant has a redesigned flow path that provides better cooling to the cylinder heads. The coolant flows through the cylinder heads first, then into the block, which helps keep the heads cooler and reduces the risk of engine damage.
- Aluminum block, which conducts heat more efficiently than the cast iron block used in the earlier engines. This allows for more efficient cooling of the engine as a whole, including the cylinders.
Overall, it has a more advanced and efficient cooling system. This helps ensure that the engine runs at a consistent temperature, which is important for both performance and durability.
Chevrolet Changed the Firing Order
Chevrolet changed the firing order for these engines for a couple of reasons.
- Improved combustion efficiency: The LS engine's new firing order (1-8-7-2-6-5-4-3) provides improved combustion efficiency by alternating the firing order between the cylinder banks. This firing order creates a more balanced power stroke and reduces cylinder pressure variation, which helps improve power and reduce engine vibration.
- Better compatibility with modern engine management systems because the LS engine's new firing order is also more compatible with modern engine management systems. These systems rely on precise timing and firing events to optimize performance and fuel efficiency. The engine's firing order makes it easier for these systems to achieve precise engine control, resulting in better performance and fuel efficiency.
It's worth noting that the LS engine's firing order is not the only factor that contributes to its improved performance and efficiency. The LS engine also features a number of other advanced design features, such as aluminum construction, advanced cylinder head design, and electronic fuel injection, that all work together to make it a highly efficient and powerful engine.
The Differences Between Chevy 350 and LS Engines
There are many differences between the pre-LS Chevy 350 and LS engines, including:
- Design: The LS engine is a more modern engine design that features an aluminum block and cylinder heads, whereas the pre-LS engine has a cast iron block and heads.
- Displacement: The LS engine is available in a range of displacements, including 4.8L, 5.3L, 6.0L, and 6.2L, while the pre-LS engine was typically available in a single 5.7L displacement.
- Firing order: The LS engine has a different firing order than the pre-LS engine, with a 1-8-7-2-6-5-4-3 firing order compared to the pre-LS engine's 1-8-4-3-6-5-7-2 firing order.
- Fuel delivery: The LS engine typically uses electronic fuel injection (EFI) for fuel delivery, whereas the pre-LS engine typically used a carburetor.
- Ignition system: The LS engine uses a coil-near-plug ignition system, while the pre-LS engine used a distributor-based ignition system.
- Cooling system: The LS engine has a more advanced cooling system design, with a redesigned coolant flow path and improved water jacket design, compared to the pre-LS engine.
- Cylinder head design: The LS engine features a more advanced cylinder head design with better airflow and improved combustion efficiency compared to the pre-LS engine.
- Variable valve timing: Some LS engines feature variable valve timing, which can adjust valve timing for better power and efficiency, a feature that is not present in the pre-LS engine.
Overall, the LS engine is a more advanced and efficient engine than the pre-LS engine, with better performance, fuel economy, and reliability. The LS engine is also more adaptable to modern engine management systems, making it easier to tune and modify for specific applications.
How Much Boost Can the LS Chevrolet Engine Handle
The amount of boost that an LS engine can handle depends on several factors, including the specific LS engine, its internal components, and the quality of the turbo or supercharger system being used. However, in general, LS engines are known to be able to handle relatively high levels of boost.
With proper modifications and supporting components, an LS engine can typically handle boost levels in the range of 8 to 20 psi (pounds per square inch) or more. However, the exact boost level that an LS engine can handle will depend on several factors, such as the engine's internal components, including the pistons, rods, crankshaft, and cylinder heads. It's important to note that adding boost to an engine requires careful tuning and attention to detail to ensure that the engine is running safely and reliably. Boost places additional stress on the engine's internal components, and if the engine is not built or tuned properly, it can lead to engine damage or failure. It's also important to choose a quality turbo or supercharger system and supporting components, such as an intercooler, fuel system upgrades, and an upgraded engine management system.