Chevy LS2 Engine Guide

In 2005, Chevrolet kicked off the fourth generation of their small-block engine series with the unveiling of the LS2 engine. The Chevy LS2 is a 6.0 liter V8 engine that lasted in production until 2009. Though it only had a relatively limited run, it is still considered one of the top Chevy small-block engines ever. Chevrolet put it inside their 2005-2007 Corvette, as well as their SSR and Trailblazer SS. It quickly earned a reputation as a very powerful and robust machine, and it’s still widely used in drag racing builds today.

This guide will provide everything you need to know about the Chevy LS2 engine. We’ll go through the LS2 specifications, vehicle applications, history, engine design, different variants, and reliability, as well as potential upgrade paths. This is your go-to article for any and all relevant LS2 information.

The Variants

In addition to the LS2, GM also released three variants: the L76, L77, and L98. These were similar in design to the LS2, but had improvements like Variable Valve Timing, flex-fuel compatibility, and/or Active Fuel Management – depending on the specific engine. These lasted until the 2017 production year for the L77, and were primarily designed for use in the Australian market by GM’s former subsidiary Holden, though some have also been used stateside.

Engine Specs

Engine	LS2, L76, L77, L98
Family	GM Gen IV Small Block
Model Years	2005-2017
Displacement	6.0 L (364 cid)
Aspiration	Natural
Configuration	V8
Fuel	Petrol; E85 (L77)
Compression Ratio	10.9:1 (LS2); 10.4:1 (L76/77/98); 9.4:1 (L76)
Bore and Stroke	4.0 in x 3.62 in
Valve Train	OHV (16V)
Fuel System	Sequential Multi-Port Fuel Injection
Head/Block Material	Aluminum
Horsepower Output	300-400 Horsepower
Torque Output	360-400 lb-ft of Torque

Vehicle Applications

LS2 Vehicle Applications

• 2005–2007 Chevrolet Corvette
• 2005–2006 Chevrolet SSR
• 2005–2008 HSV Clubsport R8
• 2005–2006 HSV Coupé GTO
• 2005–2008 HSV GTS
• 2005–2008 HSV Grange
• 2005–2008 HSV Maloo R8
• 2005–2008 HSV Senator Signature
• 2005–2006 HSV SV6000
• 2005–2006 Pontiac GTO
• 2005–2006 Vauxhall Monaro VXR
• 2006–2007 Cadillac CTS-V
• 2006–2009 Chevrolet TrailBlazer SS
• 2008–2009 Saab 9-7X Aero

L76 Vehicle Applications

• 2006–2010 Holden Commodore
• 2007–2013 Chevrolet Avalanche
• 2007–2009 Chevrolet Silverado 1500
• 2007–2009 Chevrolet Suburban 1500
• 2007–2009 GMC Sierra 1500
• 2007–2009 GMC Yukon XL
• 2007–2009 Pontiac G8 GT
• 2008–2010 Holden VE Ute (automatic only)
• 2008–2010 Holden WM Statesman/Caprice
• 2020 Ginetta Akula

L77 Vehicle Applications

• 2010–2017 Holden Caprice
• 2010–2017 Holden Commodore SS
• 2010–2017 Holden Sportwagon SS
• 2010–2017 Holden Ute SS
• 2011–2017 Chevrolet Caprice PPV

L98 Vehicle Applications

• 2006–2009 Holden Calais
• 2006–2010 Holden Commodore
• 2006–2009 Holden Statesman/Caprice
• 2006–2010 Holden Ute

Engine Design

The General Motors or Chevy Gen IV small-block LS2 is based on its Gen III small-block predecessor, the LS1. It has a relatively simple pushrod OHV, 2 valve per cylinder design, featuring an aluminum block and head. Compared with the LS1, the LS2 engine has a higher compression ratio at 10.9:1, higher lift cam, 15% better intake flow, and 20% better exhaust flow. Power was improved from 350 to 400 horsepower, and torque jumped too from 365 to 400 lb-ft (in the Corvette).

It was also bored out to 4.00″ from 3.898″, for a bore and stroke of 4.000″× 3.622″. This results in a total displacement of 6.0 L, an increase over the 5.7 L LS1. It also retains the six-bolt main caps, 4.40″ center bore, and deep-skirt case from the LS1. Both had steel crankshafts and sequential multi-port fuel injection, with the LS2 having 34 lb/hr flowing injectors.

In the Corvettes, the LS2’s aluminum block weighs 15 lbs less than the LS1 block. This weight reduction is courtesy of a thinner-walled exhaust manifold, smaller water pump, and a smaller oil pan. It might sound alarming that the oil pan requires a full quart less oil than the LS1, but it’s not. The pan has completely redesigned baffles to keep oil flowing through the pickup and is wingless instead of “gull-wing” design. Again, this revised oil pan was just for the Corvette version of the LS2.

The coil-near-plug ignition system was redesigned from the LS1. From 2005-2006 it had a 24 tooth reluctor-wheel setup, but that was upgraded to 58-tooth system in 2007. Taken from the LS6 for the LS2 was the PCV system.

Cylinder Heads, Sensor Relocation, and Throttle Body

The LS2 cylinder head is aluminum with cathedral ports, like the LS1 and LS6, and is very similar to the LS6. The valves are steel and measure 2.00″ for the intake and 1.55″ for the exhaust – like the LS6. The LS2 has a drive-by-wire electronic throttle control that controls a 90 mm throttle body. The exhaust manifold walls are 1mm (30%) thinner than the LS1, but it weighs less and flows 4% better.

The LS2 knock sensors are outside of the cylinder banks to allow for more precise readings. GM also moved the cam sensors to the front timing cover from behind the intake. The new pistons, which are still hypereutectic cast aluminum, have full-floating wrist pins to reduce pistons slap.

Some versions, like the Corvette, are connected to transmissions that utilize Computer Aided Gear Shifting (CAGS). This allowed Chevy to avoid the gas-guzzler tax on most LS2 equipped vehicles, because CAGS necessitates shifting from 1-4 at lower RPM. The LS2 also has a 500 RPM higher redline than the LS1, at 6,500 RPM.

The Vortec LS2 Variants: L76

There are several variants of the LS2 engine, namely the L76/77/98. These were marketed by Chevy as VortecMax engines and are very similar to the LS2 on which they are based. The main difference between the LS2 and the L76 is the introduction of Active Fuel Management (AFM). AFM, also known as displacement on demand fueling, is a feature that disables half of the engine’s cylinders at low-loads to promote fuel economy and reduce emissions.

AFM is controversial among many enthusiasts, because it requires a lower design camshaft that hurts performance. Also new for the L76 over the LS2 was the introduction of Variable Valve Timing (VVT) for the camshaft. VVT allowed for better fuel efficiency and tuning for power than non-VVT engines. This partly helped negate the effects of the lower profile cam, but the L76 was still under powered compared with the LS2. The L76 intake manifold was from the LS3 in the Corvettes, and has better flowing rectangular-ports rather than the cathedral style head.

There are several differences between the truck and car L76 engines. Much of this had to do with the engine size, as the larger truck bays could accommodate it better. The cars had lower-rise intake manifolds, intakes, and exhaust manifolds, all to accommodate the smaller bay. L76 cars have a 10.4:1 compression ratio, while trucks have a lower 9.7:1 ratio. The same fuel injection system was kept from the LS2, but with different sized injectors: 42 lb/hr @ 58 psi for cars and 30 lb/hr @ 58 psi for trucks.

The L76 lasted in production until 2010, and Chevy put it in their Suburbans, Avalanches, and Silverados. Chevy rated the L76 for cars at 355 horsepower and 384 lb-ft of torque, and trucks at 367 horsepower and 375 lb-ft.

The L77/98 Vortecs

The L77 is basically a flex-fuel version of the L76 that can run ethanol blends in addition to petrol. Besides that the engines are incredibly similar to each other, as well as the L96 iron-block version. It also has AFM but does not have VVT. The L77 was primarily used by former GM subsidiary Holden for the Australian market, though it also made it into the Chevrolet Caprice PPV.

The L98 is very similar to the L76 and L77, but does not have AFM and is not flex-fuel capable. Both the L77 and L98 use the L76 intake and exhaust manifolds, as well as PCV and oiling systems. The most powerful versions of both the L77 and L98 are rated at 362 horsepower and 391 lb-ft of torque, slightly higher than the L76.

You might be thinking, if the L76 is an LS2 without the AFM, and an L98 is an L76 with the AFM removed, is an L98 just an LS2? The answer: Yes, kind of. Overall, they are largely the same engine.The main differences are still the L98’s rectangular port heads and lower camshaft design – though that’s more aggressive than the L76. Some people actually argue the L98 will perform better than the LS2 – with similar cam profiles – due to the higher flowing rectangular port heads.

Engine Common Problems and Reliability

If there is one thing you can say about the Chevy LS2 engine, it’s that it is reliable. The entire LS-series is pretty much bulletproof in any respect, and there are really no significant problems with them. The LS2 will easily go past 200,000 miles if taken care of and with proper maintenance. At the 100,000 mile mark, these things are really just getting broken in.

Now, with that being said, there are a few things that some LS2 owners have had issues with. While we definitely would not call them common or likely issues, these have popped up for more than a few LS2 owners. The main issues are oil starvation, rocker arm bearing failure, and harmonic balancer failure.

The oil starvation issue was more related to early LS2 builds from 2005-2006. Some early C6 Corvette owners complained about oil starvation issues resulting in thrown rods. It’s not entirely clear what caused these, but it seems to have been a relatively isolated issue and the Corvette soon moved on to the LS3.

Rocker arm bearing failure is another somewhat complained about issue on the LS2. As we mentioned, the LS2 employs a pretty old-school and simple OHV pushrod configuration. Pushrods mean rocker arms, and unfortunately the rocker arms on the LS2 are prone to premature wear and failure. Stronger bearings usually fixes the problem for good.

Harmonic Balancer failure is the final issue we’ll go over on the LS2. Harmonic balancers help reduce excessive vibration from the crankshaft. For whatever reason, the LS2 harmonic balancers have attracted several complaints for premature failure. Going with an upgraded harmonic balancer kit is the best way to solve the problem.

Performance and Mods

Now onto the part you’ve been waiting for: Chevy LS2 engine performance and potential mod paths. Out of the box, the LS2 is already a very capable motor. In the 2005 Corvette, it’s capable of blasting from zero to 60 mph in just 4.3 seconds. It can do the quarter mile in 12.7 seconds @ 113 mph – pretty impressive for early 2000s small-block natural aspiration.

However, if you’re still looking to upgrade there are a lot of potential paths. The top LS2 upgrades are: intake, cylinder heads, long-tube headers, camshaft, and tuning. One of the great things about the LS-series of engines is the compatibility of many of the engine parts. In addition, because of the LS2 long cylinder sleeves, it’s great for swaps and stroker kits. LS-series engines are known for their ability to be swapped into most engine bays, and the LS2 is no different in that regard, either.

The Top 5 LS2 Mods

While it’s going to depend on your specific model for the best intake, we typically recommend a cold air intake as one of the first mods you do. One of the big decisions you’ll have to make is closed vs open airboxes. Generally, open airboxes are more susceptible to heat soak, but they allow for better airflow. Closed airboxes cut off some airflow, but they also mitigate engine heat soak for longer. For upgrading the intake on LS2 powered Corvettes, we recommend the Chevrolet Corvette C6 Vararam LS2 Intake. If you’re looking at upgrading an LS2 powered GTO, we recommend the Pontiac GTO Cold AIr Inductions LS2 Intake.

After the intake, the most important thing to upgrade on the LS2 is going to be the cylinder head. As we mentioned, the LS2 has the cathedral port design, which is much inferior to the rectangular port head design. An easy mod is to swap on an LS3 cylinder head with rectangular ports, which improves flow substantially. It is a direct fit for the LS2 without modification.

Aftermarket-wise, we recommend the Livernois Motorsports LS3 Stage 2 Cylinder Head. The Livernois head is CNC machined and 100% made in America, and is the LS3 rectangular port version. If you’re looking at making big power, the Livernois Stage 2 Head is the way to go.

After the intake manifold and cylinder head, your next mod is going to be upgrading the exhaust. A set of long-tube headers really wakes up the LS2, adding lots of power everywhere. While it will depend on your specific vehicle for exhausts, we recommend the American Racing Headers long-tube C6 Corvette headers. These headers offer the best of both worlds, with performance and reliability both guaranteed. They are 304 SS and can be had with or without cats.

Chevy LS2 Engine Legacy

The Chevy LS2 is one of the top GM small-block engines ever created. It is incredibly reliable, boasts outstanding performance, and is prime for upgrades and mods. Whether you have an early 2000s Corvette, GTO, or CTS-V, or you’re looking at an LS2 swap, you’ll be in good hands with Chevy’s 6.0 L power plant.

We’ve taken a deep look at the LS2 today, including its history, specs, vehicle applications, design, variants, reliability, and top mods. While we couldn’t include everything about the LS2, we’ve put in all the things you need to know about embarking on an LS2 journey.

Let us know in the comments below about your LS2 experiences. Do you own an LS2 or are you considering one? Drop a comment below!