LS1 Vs LS2: What’s The Best Engine For You?

Do you want to discover what makes two of the most sought-after V8s in the world today different? To determine which engine is most appropriate for your requirements, we compared the LS1 and LS2 side by side.

ls1 vs ls2

The 1990s may have been the most thrilling decade in the history of the automobile. The Americans were playing their own hand, which they were keeping close to their chest, as the Japanese were busy building some of their most incredible equipment (anyone remember the non-BMW Supra, the NSX, the GTR, or the RX7 FD?)…

… Up till 1997.

When it was Chevrolet’s chance to make a move this time, they did so elegantly by introducing the brand-new Corvette C5. Although the car had a stunning appearance, the real delight would be waiting under the hood.

ls1 vs ls2

Little did people know at the time, but the groundbreaking Gen III LS1 engine had arrived and would soon shift the game completely in the car industry.

By today’s standards, a lightweight, aluminum 5.7L small-block V8 with 345 horsepower and 350 ft/lb of torque may not sound amazing, but this was just the beginning.

What would follow is the sheer inability to open your social media feed more than 20 years later without having to scroll through “LS SWAP THE WORLD” memes.

In this article, we’ll pit the LS1 against the LS2, its younger sibling, to see which V8 engine is better for your requirements and to determine whether all the LS adoration is actually justified.

Are LS engines the ULTIMATE swap? Donut Media voice there opinions here:

LS1 (Gen III) History

The 1955-first-released basic small-block underwent its first significant revision with the LS1.

This infamous engine was already one of the most well-liked options in a variety of motorsports, especially the drag-racing scene, due to its performance, accessibility, and dependability.

They immediately started to work on creating the LS1 engine, which would be their most amazing engine yet, after releasing their LT1 (Gen II) engine into the market in 1992.

Do you want to know how the LS1 compares to the LT1? We specifically wrote the LT1 vs. LS1 functionality for you.

The Gen III was already a cast-iron design by the time the winter of 1993 rolled around, and it was being tested to the breaking point behind closed doors.

The all-aluminum equivalent eventually got the chance to make a first impression in 1995 before making its official debut in 1997, bringing GM one step closer to their aim.

The LS1 was not only very light, but it also checked almost every other box. It produced tremendous quantities of power in a surprisingly small and effective container because, for such a tiny powerhouse, it breathed extraordinarily effectively.

ls1 vs ls2

It goes without saying that it quickly rocked the tuning industry.

Following the success of the aluminum version, GM introduced a cast iron version for use in trucks and SUVs.

This was the perfect solution for those who needed to limit the power, but it was also much stronger, enabling even more impressive power statistics.

The cast iron block, which weighs 216 pounds as opposed to the normal 106 pounds, is undoubtedly heavier, but it offered the ideal answer for those who wanted to push the engine beyond its factory capability of 700–700 hp.

The quantity of horsepower was constantly increasing as users pushed the cast iron blocks to what seemed like insurmountable limits, and with the right additions, jaw-dropping numbers like 1,400 horsepower were soon within reach.

You may be excused for believing that the LS2 replaced the LS1. In actuality, the LS6, which is found in the Z06, was the first to hit the market. Later, it was also used into the Cadillac CTS-V.

The LS6 was essentially an improved, high-performance LS1 with improved cylinder head design, stronger internals, higher compression, and better airflow.

After only a brief time on the market, the LS6 would serve as the ideal precursor to the release of the LS2, which had many of the same components but was mass-produced.

Check out this informative video which shows the history of the LS engine:

LS2 (Gen IV) History

When the highly appreciated LS2 hit the market in 2005, it would be time for GM to discontinue the ultimately honed combo of the LS1 and LS6.

400bhp and 400ft/lb of torque are produced at a redline of 6,500 rpm right out of the factory. Once more, it left tuners and auto fans clamoring to get their hands on this brand-new 6.0L offering.

The LS2 and LS6 share a lot of characteristics, but the LS2 has a better block casting, better torque over the rpm range, larger bores, and a smaller camshaft. The LS1 and LS6 have compression ratios of 10.25:1 and 10.5:1, respectively. Compression was increased once more to 10.9:1.

ls2 engine

Despite the modifications, the blocks are sufficiently similar that a lot of the Gen III components can be easily swapped out. This suggests, for instance, that LS6 cylinder heads may be used on an LS2.

Given the similarities, there have been many debates over the years about whether the LS2 needed a completely new generation. It was undoubtedly a worthwhile improvement over its forerunners.

What makes the LS engines so popular?

Fanboys have been extolling the virtues of LS engines at great length. Are they worthy of the hype?

When it came to creating cylinder heads with absurdly high flow rates, GM truly hit the mark. An engine can produce more power the more air it can fit inside of it, and the LS is undoubtedly one of the best-breathing engines available.

Because they are lightweight and can generate enormous amounts of power from modestly tiny containers, these products are becoming increasingly popular.

The title of this article from THE DRIVE gives a hint as to what they think about the LS.

The aluminum block makes it not only lightweight and remarkably sturdy considering its size, but also capable of producing significant power figures. Additionally, it warms up and cools down far more quickly than the thick and hefty cast-iron version.

The degree to which the parts of the various engines in the LS series are interchangeable is another advantage. You’ll probably discover spares and parts very easily, from cylinder heads to crankshafts, intake manifolds, and more.

ls1 vs ls2

We’ve heard of owners fitting an LS2 head to an LS1, which in effect almost creates an LS6 engine. (If only it was that convenient for all motors, huh?)

Be warned though, not every part matches every combination, so make sure you do your own research to avoid disappointment.

Some enthusiasts will claim they’re the best sounding thing on the planet, but we’ll let you decide that one!

If you’re into LS swaps, one of our favorites of all time has to be Joachim Waagard’s controversial RX-7 FD LS2!

We’ve got a whole lotta love for this LS-powered Hyundai Genesis throwing down big angle at the track!

What are the differences between the LS1 and LS2?

Despite undoubtedly being mostly based on the original architecture of the Gen III, GM opted to rebrand the LS2 as the Gen IV small-block, with the 2005-launched LS2 being the first of many engines to follow.

The displacement, cylinder heads, throttle body, and intake are the main differences between the two, and even some of these revisions are minor!

Alongside the displacement increase from 5.7L to 6.0L, one of the main changes with the LS2 was that it utilized a new block casting. Several sensor locations have been relocated to make way for GM’s Displacement on Demand cylinder deactivation technology.

Cylinder Heads

Despite the LS1 head being known for its impressive airflow, the LS2 managed to offer even more efficiency by utilizing the tried-and-tested, improved cylinder heads which initially featured on the LS6.

The LS2 features raised intake ports and a combustion chamber design with unshrouded valves, which, when combined with the engines flat-top pistons produces an improved air/fuel mixture.

LS engines are excellent candidates to fit stroker kits to. After all, there really is no replacement for displacment.. You can find out more from our stroker engine article.

This, combined with the revised flat-top piston, provides a higher compression ratio of 10.9:1 compared to the 10.1:1 which was found on the LS1, and 10.5:1 on the LS6. The end results are the improved horsepower and fuel economy which were achieved over the LS1.

The LS2’s valves measure 2.00 inches for the intake and 1.55 inches for the exhaust. The valve springs are designed to handle the engine’s 6500-rpm rev range.

The LS1 cylinder bores measured at 3.898 inches, however, the LS2 was increased to 4.000 inches.

Pistons

The main changes here are a true flat-top design and a revised tension ring, which free up more horsepower. The Gen III engines sometimes suffered from a “piston slap” sound, which has been rectified in the LS2 by fitting full-floating wrist pins.

Intake Manifold

The LS2’s intake manifold is mostly the same, although they also required some adaptations for the new sensor locations.

Exhaust Manifold

One of the most substantial amendments was the lighter exhaust manifolds, which are now are apparently one-third lighter than they were in the LS1, which also provided improved flow thanks to a reduction of the wall thickness. This provides around a four-percent increase in overall flow.

Oil Pan

Located at the bottom of the block of Corvette LS2’s, a revised oil pan with redesigned baffles ensure an adequate oil supply during high-load situations. This was due to oil starvation issues found on the LS1 fitted in the Corvette’s when used under heavy situations, such as being pushed to its limits on the track.

Camshaft

GM once again opted to utilize the parts found in the LS6 for the high-lift camshaft.

Throttle Body

One of the biggest changes was the addition of a huge, single-blade 90mm throttle body which incorporates Electronic Throttle Control (ETC) for the first time. This electronically controlled fly-by-wire replaced the traditional cable throttle body which was previously found in the LS1.

The LS2’s throttle body is mounted to the intake manifold on a slight upward angle to reduce water puddling at the bottom of the throttle body. The manifold itself isn’t revolutionary; just an evolution of the cross-over plenum design of the LS1 and LS6.

Water Pump

The water pump received a revised design with improved sealing to reduce its chances of leaking.

Coil Pack System

A new, improved coil pack system was introduced for the LS2. These are far more efficient and require less energy to deliver the same spark as the LS1 coil packs.

Visual Differences

Want to make sure you’re DEFINITELY bagging yourself an LS2 and not an LS1? Admittedly, they’re not too easy to tell apart! Here are the main differences externally:

Throttle Body

As mentioned above, this is the electronic fly-by-wire on the LS2 and original cable throttle for the LS1.

Knock Sensors

These are found on the side of the block on the LS2 and under the valley cover on LS1’s.

Cam Position Sensor

This is found in the driver side of the timing cover on LS2’s and at the rear of the engine behind the intake manifold at the top of the block on LS1’s.

Engine Block Stamp

It’s a little hard to find with the engine fitted, but LS2’s will have a 6.0L stamped into the block.

SHOULD we LS swap all the things?

You were hoping you were going to get away without a meme, weren’t you? (Sorry, not sorry.)

ls swap all the things

But, on a serious note, do the annoying distant friends that insist on spamming your news feed have a point?

The LS is light, cheap, and has heaps of power for the money. It’s also pretty compact considering, meaning that it can fit in most averaged-sized engine bays.

If you’re considering swapping an LS into something unique and throwing it down sideways at the track, you’re going to want to check out our How To Drift article for everything you need to know.

There’s no question that it’s is one of the most sought after series of engines in the world right now, and with ever-growing inflation on the JDM scene-tax, it’s easy to see why people are potentially choosing these over 2JZ’s, for example.

slivia ls swap

Then, there’s the reliability. Since they’re capable of around 700hp on stock internals, there are not many, if any, JDM alternatives that can truly match it. Especially not for the price.

We love crazy swaps, and this ridiculous sounding supercharged LS2 Volvo 240 ticks all the right boxes!

For this reason, we’ve seen them placed in just about any bay you can think of over the years. From Miata’s and 240s, right the way through to classic SUV’s.

Rather unsurprisingly, the LS has also managed to maintain its spot at the top of the drift scene for many years, too. Some might think its played out now, but to be honest, we can understand the appeal.

Given that it’s often the same size, or even smaller, than some of the stock turbo 4-cylinder engine that owners replace them with. At the same time, they have no turbo lag – or turbos to go wrong for that matter (although if you do want to shoot for crazy LS1 power, our LS1 turbo kit guide will be just what your looking for).

If it does go completely wrong, chances are, especially if you’re based in the US, that you can conveniently pick one up for a reasonable price at your local junkyard. We wish the same could be said for the likes of the 2JZ!

If you’ve managed to source an LS, but you’re not sure what you want to throw it into, then our 11 Best Budget Project Cars article will certainly give you some reasonably-priced ideas.

Enjoy looking at ridiculous swaps? You’re gonna love this:

Power Upgrades

For a naturally aspirated engine, producing some worthwhile power gains from the LS is easily achievable.

The natural route would be to begin with the air intake, move on to a cat-back exhaust, headers and then consider head and cam upgrades.

Depending which engine you have, it’s certainly worth checking if uprated parts are interchangeable. For example, with the LS1 engine, the LS6 intake is a popular, inexpensive upgrade.

On top of that, you can also consider mods such as NOS, which is likely to produce huge power gains for the cost but will, of course, put a lot of strain on the engine.

If you’ve got the budget to go all-out, you’ll be amazed by what can be achieved with the right upgrades!

Interested in building a decent spec car? Our How Much Do You Need for a Top-Tier Tune Up? guide will undoubtedly give you a useful insight into what you can expect.

Check out this video for everything you need to know when it comes to modifying an LS1:

Curious about what the LS2 stock bottom end is capable of? We’d say this is about as far as you can safely go!

Which cars left the factory with LS1 & LS2 engines?

Bagging yourself a cheap LS will undoubtedly be an epic buy. With the ease of rebuilding, don’t be scared to take on a project even if it does initially seem a little daunting.

With a wide variety of interchangeable parts, they’re one of the most convenient engines to build on the market.

LS1

The LS1 engines were produced between the 97 and 04 model years in the U.S, and into 05 on the international market.

If you’re looking for a cheap LS1, they can be found in the following cars:

  • Chevrolet Corvette C5
  • Chevrolet Camaro
  • Pontiac Firebird
  • Pontiac GTO

LS2

From 2005 onwards, the LS2 could be found in the following cars:

  • Chevrolet Corvette C6
  • Chevrolet SSR (Super Sport Roadster)
  • Pontiac GTO
  • Chevrolet TrailBlazer SS
  • Cadillac CTS-V (06-07)
  • Holden Special Vehicles
  • Saab 9-7X Aero
  • Vauxhall Monaro VXR

You will, of course, want to check that it’s got the correct motor under the hood before purchasing!

Alternatively, if you’re planning to make huge power, then the iron block configurations are undoubtedly worth considering.

LS1 vs LS2: Which is best? The conclusion

So, we’ve reached the point where we’ve got to ‘that’ question!

Now, if you’ve made it this far, you’re probably thinking that it’s a no brainer. Not only was the LS2 the revised equivalent, but they even had a stepping-stone in the middle with the LS6 to refine it even further from the LS1.

The LS2 certainly wins when it comes down to power, torque and fuel economy.

However, how about if we’re talking bang for your buck?

There are undoubtedly some extremely cheap LS1 engines to be had out there, and while the obviously convenient choice would be the LS2, with slightly more aggressive cams, better flowing heads, and a larger bore – is the difference really that substantial?

The LS1 does have a slight lack of torque low down, where the LS2 doesn’t struggle as much. However, if you’re planning to be upgrading an LS1, chances are you’ll be eliminating that anyway.

For some owners, they want the best option regardless of expense, and that’s completely understandable. However, at the same time, many owners would rather pay substantially less money for an LS1 and then do the necessary upgrades to make it more epic than a stock LS2 AND still have money left over at the end.

350z ls swap

If you got your hands on a stock LS1, you could then source an LS6 intake and then change the cam and heads. This will provide you with fantastic power gains and improved MPG.

If you want to spend even more, you could consider going down the supercharger route and pushing the true potential of what its really capable of.

On the other hand, if money isn’t an issue, or you’ve managed to get your hands on a cheap LS2, then it’ll likely be the more convenient option to go for.

The LS2 already features a better block, better heads and LS6-type cam which most LS1 owners would likely upgrade to as a minimum. Alongside that, it also has full-floating pistons, a higher compression ratio, a higher RPM limit, larger bore cylinder heads, much hotter ignition coils and a better timing chain.

rx7 ls1 swap

The LS2 also has the convenience of being one of the most adaptable engines, with the ability to fit LS1, LS6, LS3, and L92 cylinder heads.

In summary, the LS2 is clearly the better all-around package from the factory. However, it’s worth working out whether pouring out that extra cash on an expensive LS2 could, in fact, be better spent improving the humble LS1, which is certainly no slouch!

Either way, we have no doubt that you’ll be delighted when you fire it up and hear this V8 beast roar!

Additional Videos

We know that you guys love browsing through hours of epic YouTube content, so we’ve provided some of our favorite LS clips!

Thank you for reading our LS1 vs LS2 comparison guide

We hope that you’ve gained a wealth of knowledge and can finally choose the V8 powerplant you’ve been hoping for!

Whether you’re planning to buy a factory LS or swap one into your crazy build, we have no doubt that it’s going to be an epic addition to your car (or boat, helicopter?)

If you enjoyed this article then please share it with the buttons at the side and bottom of your screen. Find this information useful? Please post a link to it on your cars owners club. We really appreciate your support.

Decided that the LS doesn’t suit your needs? Why not consider going down the JDM route? We have a guide comparing two of the best in our 1JZ vs 2JZ guide!

Interested in learning more about other legendary Japanese powerplants? Then, check out our VQ35DE, K24, RB25DETT, and SR20DET guides.

If you are interested in V8’s you might want to check out our article on GM’s big block Vortec 8100 or their 4.2L Vortec 4200 engine here.

Photography credits

We thank the following entities for use of their photography in this article:

author avatar
Written by Joe Terrell

Joe is an avid writer and car enthusiast. When he’s not cruising the streets alongside his friends in his Nissan Silvia S15, he’s drifting on his VR racing simulator.

Joe’s passion for cars is always on display. With a keen eye for detail and a deep understanding of the automotive industry, he hopes his writing conveys his excitement and knowledge of cars and games.

Joe’s work has been featured on many platforms including drivetribe.com, smartdrivinggames.com, carthrottle.com, databox.com and ceoblognation.com.

When he’s not behind the wheel or at his keyboard, he’s likely daydreaming of his ultimate ride – the legendary Lexus LFA.

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