In a few months, the LS engine will celebrate its 25th anniversary. Since it was first introduced in 1997, the LS went on to become the most well-known engine in North America and among the most popular engines across the planet. The LS has reached the level of stardom where it’s used as an adjective.

‘LS swap it’ is a phrase familiar to most automotive enthusiasts across the world. The V8 engine has been swapped into various cars, trucks, and boats while some have even used it to power a motorcycle. The LS engine had to have done something right to achieve such a high degree of cult status. In this guide, we’ll discuss the rise of the LS engine, what makes it so popular, and we’ll also run through its variants.

History of GM LS Engine

While the LS has been replaced by the LT series, this engine was used for 20 years. Two decades is an extraordinarily long time for an engine series to be around. Especially in a world where technology is developing at such a fast rate. Add to that the ever-changing emission norms in the last two decades, and it becomes obvious that what the LS (Luxury Sport) engine has achieved is no simple feat. It shouldn’t come as a surprise that this successful V8 engine is made by GM – a company that is known for using V8 designs in vehicles for over 100 years!

LS was the designation of 3rd and 4th generation small block V8 engines from General Motors. When it arrived in the 1990s, the LS engine was at the heart of the Chevrolet Corvette. The LS engine was the only option available with the C5 and C6 generation Corvettes. Needless to say, both of these cars were successful and responsible for shaping the Corvette brand. 

The contribution of the LS engine didn’t go unnoticed. The car community quickly realized this platform’s potential, and the LS soon became known for its performance, durability, and reliability. The LS engine was somewhat revolutionary at the time as it made use of aluminum, instead of using iron. That not only helped reduce the engine’s weight significantly, but that  decrease in weight also improved performance.

The LS engine wasn’t just well-received by Corvette or GM enthusiasts but among owners of a variety of cars worldwide. GM was quick to spread the LS love throughout its brands. The Chevrolet Camaro, and Pontiac GTO, Australia’s Holden all used the LS engine in their high-performance offerings. There are many different versions of the popular engine series and many of them can be found on GM trucks along with the likes of 5.3 Vortec small blocks. The LS engines used in trucks used iron blocks instead of aluminum. 

What Makes the LS Engine So Good?

Today, the LS engine is regarded as one of the most popular swap options for just about any car with enough room in the engine bay. You can find the LS engines being used in cars as small as the Mazda Miatas to off-road-oriented Jeep Wranglers. While swapping the LS engine required custom fabrication early on, some companies make kits for this purpose. Swapping in an LS engine is easy as can be and a lot more cost-effective than other engine swaps.

To better understand the legacy of the LS engine, we’ve put together a summary of what made it so good. While the LS was a new design, it featured some design elements of its predecessors. For instance, it carried forward the same bore spacing and bell housing bolt pattern as the older small-block V8s from GM. This was done intentionally to make sure the LS engine could be fitted to older vehicles.

That being said, the overall design was still new and modular. Interestingly, GM went out of its way to ensure that most components between different generations of the LS are interchangeable. Almost every LS engine uses high airflow aluminum cylinder heads, which was one of its highlights. 

At the time, other companies were making the switch to modern DOHC configurations, but GM continued to use a pushrod setup for this engine. This was seen as a conventional choice especially when you consider that GM’s main rival, Ford, had made the switch to DOHC. However, it turned out to be a smart choice for GM as this made the engine quite cost-efficient and easy to use in many vehicles.

The LS engine’s compact size was a major contributing factor to its success. GM could also make the LS high-capacity as they were saving in terms of space in other areas. The high flow cylinder heads also meant that the engine was always breathing well. When you take into consideration these qualities, it shouldn’t come as a surprise as to how good a package this engine was.

We haven’t even addressed the massive aftermarket that exists for the LS engine. There are thousands of parts available to tweak an LS setup, and tune it to meet your exact needs. Years of development also means that you can get tried and tested components. In other words, bolt-on upgrades are numerous for this platform. Off-the-shelf components like superchargers and turbo kits can take the LS engine to the next level in terms of performance. To give you an idea, people have achieved over 1500 HP with heavily modified LS engines.

The Art of Stroking an LS

Speaking of modified LS engines, it is a good candidate for a stroker kit. If you are familiar with the technicalities of an engine, you probably already know what the bore and stroke of an engine are. And to increase the displacement of an engine, the size of either or both has to be increased. Stroking is essentially lengthening the throw on the crank to increase displacement.

As we mentioned before the LS engine uses a fairly straightforward design. The pushrod tech makes it easy to work on which has also driven up the interest in modifying it. After the LS, GM began moving away from the pushrod V8 setup which means it will likely be one of the last engines of its kind to be mass-produced.

The LS is a sweet platform, to begin with, it has multiple features that already help it achieve some big power numbers. To reiterate, the impressive airflow, 15-degree valve angle, and 55 mm camshaft diameter meant it was quite the hoot right out of the box.

Interestingly, the engineer made sure to take inspiration from earlier V8 engines when building this one. The engine was completely fresh, but it featured the good bits from the company’s other engines. When it comes to stroking the LS engine, two things make it a good option.

Firstly, the potential of the cylinder heads. While they are quite potent in stock form, mild porting can allow enough airflow to support increased displacement. If porting is not your thing, there are several aftermarket options on offer. The LS also has a raised cam tunnel. What this means is that the LS can handle an increased stroke without needing additional clearance. However, if you do decide to go the aftermarket route, you can increase the capacity to over 500 cubic inches.

However, properly stroking an LS requires some serious know how. Installing a big crank kit in a short deck block usually means that your pistons will go too far down on the down stroke. When that happens, the side skirts of the piston leave the bore at which point the piston no longer has anything to support it. 

The piston also tilts slightly to one side before being violently pushed back up by the crank. The end result is often a piston with worn side skirts that is no longer effective. The only way to avoid such issues to start with a tall deck block or a short deck block with extended sleeves. This is also the reason why the LS7 features extended sleeves. 

How to Extract More Power?

While stroking will certainly improve the LS’ performance, you can also take the forced induction route to extract more power. 

Supercharged vs Turbocharged LS Engine 

The LS engine is extremely welcoming to modifications and this includes major ones like adding forced induction. It is also quite typical in the way it responds to turbochargers and superchargers. What this means is that with a supercharger the installation process will be fairly straightforward. It will increase power and also deliver it without lag, unlike a turbocharger. With a supercharger, the power will be available from low RPMs.

Turbocharging an LS engine is more expensive in comparison, but there is a much larger horsepower gain. A turbocharger is powered by exhaust gasses and not the engine which makes it more efficient. That being said, a turbocharged LS engine isn’t perfect as turbos often mean lag. 

Whether you turbocharge or supercharge the LS engine, it will require supporting modifications and upgraded internals to make big power, especially if you are looking to ensure reliability. 

GM LS Engine Variants

By all standards, 20 years is a long time for an engine to be around. As you can probably imagine, there have been at least several iterations of the LS platform since it was first introduced. Not only is that true, but some variants stand out more than others.

LS7

One of the most iconic versions of the LS engine has to be the LS7. This was the engine that powered the Corvette Z06 which went on to make an ever-lasting impact on the global car scene. This LS engine version took everything this engine series was known for and took it to the next level. It was also made to spin up to 7,000 RPM, which is rather impressive for a V8 of this kind.

LS2

The LS2 made its debut on the Corvette C6. This 6.0-liter engine was the first Generation 4 LS engine and made use of a bigger bore to bump up the displacement. The LS2 was also known for its uniquely designed cylinder head. The LS2 also had a fairly high compression ratio of 10.9:1. Another impressive feature of this engine was that it was adapted for use on SUVs and pickup trucks as well.

LM7/LY6

The LM7 and LY6 are two different versions of the LS engine, but quite similar in terms of characteristics. The LM7 is 5.3-liter and the LY6 is 6.0-liter. Both engines use iron blocks and have been used in GM’s trucks for many years. 

At the same time, these engines aren’t as popular as the rest because they don’t make big power numbers. However, these two are still quite powerful and designed to be workhorses. By running iron blocks, the LM7 and LY6 both handle boost quite well. 

LS9

At one point in time, the LS9 was General Motors’ most powerful engine. It made 638 HP in the Corvette ZR1 and was able to achieve the figure thanks to the supercharger it was paired to. This engine also helped the ZR1 achieve record-breaking acceleration and top speed numbers. The LS9 can also be considered to be one of the most aggressive LS engines ever made.

LS3

The LS3 might not be the most popular LS engine out there, but it has become one of the most popular LS engine swaps. In stock form, the LS3 engine makes 430 HP and can be found at a fairly competitive price tag. This makes it one of the best values in the LS engine world. The engine also has the potential to cross the 500 HP level with a few straightforward modifications. 

LS1

Last, but certainly not the least is the LS1 engine. The LS1, as its name suggests, was the first LS engine. At first, many considered this engine to be outdated in terms of its tech and equipment, but that changed once people began experiencing it. Despite being a pushrod V8, the engine easily hit high RPMs. People also began realizing that despite being brand new, the tech on the LS1 was tried and tested, making it quite a bulletproof setup. 

LS VS Chevy Small Block

While the LS and Chevy small block are quite different, but also similar in some ways. For instance, both engines have similar capacities and use single camshafts. Both also feature an old-school two-valve-per-cylinder setup. The differences, meanwhile, come into view in the form of electronic fuel injection and other comparatively modern components. Speaking of the EFI system, it’s significantly more efficient than the carburetor found on the Chevy small block.

Interestingly, the LS is known for being lightweight , and it is but only with its aluminum block. The iron-block LS, on the other hand, is around 25 pounds heavier than the small block. That said, the additional weight is a result of a stronger block. Another difference comes in the form of the LS’ skirted design – another measure to improve strength as it added rigidity. 

The LS engine also has a crankshaft that can handle higher power levels right out of the factory. There have been multiple instances where people have made over 1000 HP with a stock crankshaft. In comparison, the crankshaft on the Chevy small block would only be good for around half that.

GM also made sure to use hyper eutectic pistons on the LS. This means they expand less at high heat while allowing tighter tolerances. The LS also uses improved rods and connecting rods which can also handle more power than the ones on the small block. The LS’ most impressive advantage though is its cylinder head. As we mentioned earlier, it flows an impressive amount of air. The improved chamber style and steam vents were the biggest contributing factors. The LS engine also has redesigned camshafts and rocker’s arms – both of which are also more capable than the ones on the Chevy small block.

LS Engine  – Problems

At this point, the LS might seem like it’s quite bulletproof and while it comes close, it’s not perfect. Here are some problems you should know about. These problems are limited to certain versions of the LS engine.

Pushrod Wear

The pushrod configuration the LS engine uses certainly has its advantages, especially in terms of keeping the engine compact. At the same time, this design has its own limitations. Pushrod and rocker arm wear is a known issue in many LS engines. 

It’s not uncommon to find worn rocker arms on engines that otherwise look fairly healthy. Many builders replace these even before they pull out the parts cannon. 

Oil Pump Issue

Some LS engines come with oil pumps which are known to be inefficient above 6,000 RPM. More importantly, the oil pumps on these motors can sometimes have their oil pressure relief valve stuck open, causing the oil which would otherwise be sent into the engine, to be dumped and recirculated by the pump. Of course, the oil starvation issues caused by such a failure can be catastrophic. 

Bad Piston Ring Seals

There have been numerous reports on a few different LS engines facing piston ring seal failure. While the first symptom isn’t as serious and can be something as small as a bump in oil consumption, it will become quite problematic if left unattended. The oil consumption can also reach a level where the blow-by increases significantly.

LS Engine – Availability

When it comes to LS engines, availability isn’t something you need to be concerned about. Even though General Motors doesn’t use the engine in their vehicles anymore, there are many brand-new crate motors available at any given time. If brand-new motors aren’t your thing, you can pick up a decent used motor for as little as $500. To give you an idea of the other end of the scale, a souped-up LS crate motor can even set you back by over $15,000. In short, there’s an LS engine out there for everyone.

Maintenance Is Everything 

The key to a healthy LS engine, whether stock or fully built, is proper maintenance. Here at Newparts.com we offer a wide range of genuine, OEM and aftermarket parts for the LS platform, as well as many other vehicles, both imported and domestic. To find what you’re looking for, head over to our store and select your vehicle using our store navigation tool. Then, simply search for the parts you need, and you’ll be presented with a list of products that are a guaranteed fit for your car.