LS1 vs LS2 vs LS3 Engine Comparison: Specs, Performance and Upgrade

In simple terms, apart from the details in the above table, the key differences between the 3 engines are the improvements to the construction of the engine block to increase durability along with improved rotating assembly components.

The introduction of the rectangular port design in the LS3 provided better airflow at higher RPM and for a longer power band whilst also not sacrificing low-end torque.

As each series progressed, General Motors (and its subsidiaries) would continue to tweak and improve certain aspects of the engine to squeeze extra performance without compromising the overall driveability and reliability, which is crucial for a new vehicle.

The LS1 saw the most significant gains over its lifetime as manufactures came to grips with the leap from the older Gen-2 Small Block Chevy to the more modern Gen-3 architecture.

Common Upgrades

Like their Gen-2 small block predecessor, the LS engines are a darling of the aftermarket parts world. Depending on your skill or knowledge level, the simplicity of the LS makes working on these engines far easier than an equivalent overhead camshaft v8 of the same era, thanks to GM retaining the pushrod actuated valvetrain design.

Upgrades don’t always necessarily need to be performance based either. For some, the look of the engine is just as important as the power.

Items such as valve covers can drastically change the look of the LS as, unlike older small blocks, they also are responsible for proving a mounting point for the ignition coils and that is also where ignition coil relocation brackets and wiring harnesses come into play.

• Browse LS valve covers to upgrade the look of your engine bay
• Browse LS ignition coils and coil relocation parts

However if performance is the name of the game, and you’ve just got yourself a new camshaft then you’ll no doubt be looking to upgrade your valvetrain, fuel and intake systems.

Supporting modifications such as roller rockers are a great way to reduce valvetrain friction and improve high RPM stability. With the increase in power comes the requirement for increased air and fuel flow.

Larger throttle bodies will allow for increased air-flow however if the opening in the intake manifold is too small the benefits from the change in size are limited; that’s where you would start to look at intake manifolds, such as the fabricated or cast aluminium open plenum style units.

• Browse LS cylinder heads for airflow and performance upgrades
• Browse LS throttle bodies for increased airflow
• Browse LS intake manifolds for high-performance builds

Reliability and Maintenance

Generally speaking, the LS platform is very reliable thanks to its relatively simplistic design and robust construction. Engines are known to go for hundreds of thousands of kilometres with only regular servicing; but like any engine there can be issues.

The LS1’s were prone to piston slap when the engine was cold but this generally was harmless.

Applicable to the wider series of engines, lifter failure and broken valve springs can be a problem for some but this is generally caused by increasing performance without upgrading the stock componentry to match the requirements, therefore demanding more from the OE parts.

Providing that you upgrade the components accordingly when demanding more from your LS engine, you should have a reliable and very capable powerplant for years to come.

Which Engine Is Better for Different Builds?

This topic is very subjective; you need to sit back and ask yourself – what do I want from my vehicle? As there hasn’t been any new domestically made vehicles fitted with LS engines since 2017 in Australia, and that they have been around since 1999, the days of picking up a cheap LS1 from a wrecked Commodore are no longer a reality for most.

With that said there are still plenty of used LS engines out there, just that their prices have increased quite a bit over the years. On the other hand, new LS crate engines are an option for those who want a no-fuss solution with a warranty.

Depending on which state you reside in will also determine which series you choose as displacement verses vehicle weight can restrict the capacity you can install; or what the maximum engine size was originally from the factory.

Engine swaps are some of the most common applications for the LS series as its size, weight, reliability and power potential makes them a clear winner over most other engine types.

For street applications, upgrading from an older generation small block or even a 6 cylinder will grant you with a more reliable and powerful package, and in some cases even more fuel efficient.

Because the overall dimensions are so similar to the older Small Block Chevy engines, converting to an LS is a pretty straight-forward task, especially with the myriad of adaptor mounts/brackets/plates etc. available for a wide array of vehicle applications.

Those who want to hit the race track should perhaps consider the LS3, not only for its larger displacement and higher base power numbers, but for its increased block strength when compared to its predecessors.

The durability of the LS3 block will lend itself better to higher and more sustained RPMs which is important for both circuit and drag racing.

Frequently Asked Questions

• Q. Are LS parts interchangeable between the 3 engines?
• A. Whilst most parts are compatible between them, certain components such as sensors and certain cylinder heads not interchangeable due to their different port styles (cathedral or rectangular).

• Q. If I have an LS1/LS2, should I upgrade to an LS3?
• A. Only if your budget allows, and even then it depends. If you have an LS1 then the decision is a bit clearer as there are a larger number of improvements to the overall design of the engine, not to mention the increased power. As for the LS2, because it too is part of the Gen 4 series like the LS3, there were only a few improvements between them, and as such, a well-sorted LS2 will get pretty close to an LS3 with similar upgrades.

• Q. I want to build and engine for performance; which one should I choose?
• A. The LS3 with its 6.2L capacity and stronger block it’s a pretty clear winner out of the three.

• Q. I’m wanting to swap out my old SBC for an LS. Will it fit my car?
• A. This is a very commonly asked question that always ends with the same answer; it depends. As they are dimensionally very similar, an LS will generally fit where a SBC once was, however clearances to the oil pan, exhaust headers, intake manifold etc. can be a deciding factor.

• Q. My Holden Commodore has a 6.0L LS. Is it an LS2?
• A. Unless you have a HSV Z-series, then no. Although it’s a 6.0L like the LS2, Commodore’s were fitted with derivatives of the LS2 namely the L98 and the L76. The key differences between them were the cylinder heads which were rectangular on the L98 and L76 whereas the LS2 retained the cathedral design from the LS1. The L76 was a variation of the L98 but with Displacement on Demand. The LS2 also had a more performance orientated camshaft profile which gave it higher factory power numbers, but the rectangular ports of the L97/L76 have greater flow potential.