Ultimate Chevrolet LS3 Engine Guide

At this point, more than two decades after General Motors first unleashed them on the public, the LS-series of small-block V8 engines has reached legendary status. They are widely known as being durable, reliable, and capable of producing gobs of horsepower and torque. One of the earliest LS engines that GM released was the 6.2 liter LS3 engine, which was the successor to the LS2. The LS3 lasted from the 2008–2017 model years, and Chevrolet continues to manufacture and sell it as a crate engine today. Depending on the model, the LS3 made a whopping 426-436 horsepower and 420-428 lb-ft of torque. 

Most prodigiously, Chevrolet used the LS3 inside the C6 Corvette from 2008–2013, including in the reborn Corvette Grand Sport from 2010–2013. Chevrolet also used a slightly detuned version, the L99, inside 2010–2015 Camaro SS with automatic transmissions. In addition, there are also the Vortec 6200 engines, the L92/L9H/L94, of which GM originally based the LS3 on. Read on to find out all about the LS3’s history, specs, vehicles, design, common problems, and of course, best mods. 

GM/Chevy LS3 Engine History

In 1997, GM/Chevy released the first of their third generation small-block V8s with the LS1 engine. They quickly followed this up with the LS6 in 2001 and the fourth generation small-block LS2 in 2005. In addition to the LS-series of small-blocks, GM/Chevy also released the mechanically similar Vortec small-blocks. For the most part, Chevy called the performance engines inside models like the Corvette, Camaro, and Firebird the LS-series. In contrast, they called the (usually) smaller displacement, iron block, and less powerful motors inside the SUVs and trucks the Vortec engines. 

Interestingly, the LS3 is somewhat of a hybrid fourth generation small-block Vortec and LS-series engine. This is because GM based it on the Vortec 6200 L92 engine. GM introduced the L92 Vortec 6200 in 2007 in various GMC and Cadillac SUVs and trucks. They then took the block and put on a performance intake-manifold and better flowing cylinder heads, and created the LS3. From 2008–2013, the LS3 served as the base power plant for the C6 Corvette. From 2008–2009, Chevy put it inside the Z51 Corvette, and from 2010–2013 inside the Corvette Grand Sport which replaced the Z51 option.

For 2010, Chevy also created a detuned version of the engine which they designated with the L99 engine code. Chevy only used the L99 inside the Camaro SS from 2010–2015 when equipped with an automatic transmission. The manual transmission Camaro SS from 2010–2015 used the standard LS3. From 2014–2017, the Chevrolet SS also came with the LS3. 

The Holden LS3 Vehicles

In addition, Chevrolet’s subsidiary Holden also used the LS3 inside a few models from 2009–2017. From 2009–2013, they put it inside the high performance HSV E-Series to replace the LS2, and from 2015–2017 the VF-series Commodore used it. The Chevrolet SS was a stateside version of the Commodore (VF). Additionally, Vauxhall used a version of the LS3 in their VXR8 GTS from 2009–2013. The VXR8 GTS was a rebadged HSV E-Series that Vauxhall sold in Britain.

As you can see, the LS3 has a rich history that has taken it literally all across the globe. American production of the LS3 ended in 2015 (except the Holden-based Chevy SS), while international production continued through 2017. Today, Chevrolet still sells the LS3 as a crate engine, and they have several different variations. 

GM/Chevy LS3 Engine Specs

Engine	LS3	L99
Family	Gen IV small-block V8 (LS)	Gen IV small-block V8 (LS)
Model Years	2008-2017	2010-2015
Displacement	6.2 liters (376 cid)	6.2 liters (376 cid)
Aspiration	Naturally Aspirated	Naturally Aspirated
Configuration	90º V8	90º V8
Compression Ratio	10.7:1	10.4:1
Bore and Stroke	4.065 x 3.622 in (103.25 x 92 mm)	4.065 x 3.622 in (103.25 x 92 mm)
Valve Train	16-Valve, OHV, 2 valves/cyl	16-Valve, OHV, 2 valves/cyl
Fuel System	Electronic Fuel Injection	Electronic Fuel Injection
Block Material	Cast Aluminum	Cast Aluminum
Head Material	Aluminum	Aluminum
Horsepower Output	426-436 horsepower	400 horsepower
Torque Output	420-428 lb-ft	410 lb-ft

Engine	L92	L9H	L94
Family	Gen IV small-block V8 (Vortec)	Gen IV small-block V8 (Vortec)	Gen IV small-block V8 (Vortec)
Model Years	2007-2008	2009-2013	2010-2014
Displacement	6.2 liters (376 cid)	6.2 liters (376 cid)	6.2 liters (376 cid)
Aspiration	Naturally Aspirated	Naturally Aspirated	Naturally Aspirated
Configuration	90º V8	90º V8	90º V8
Compression Ratio	10.5:1	10.5:1	10.5:1
Bore and Stroke	4.065 x 3.622 in (103.25 x 92 mm)	4.065 x 3.622 in (103.25 x 92 mm)	4.065 x 3.622 in (103.25 x 92 mm)
Valve Train	16-Valve, OHV, 2 valves/cyl	16-Valve, OHV, 2 valves/cyl	16-Valve, OHV, 2 valves/cyl
Fuel System	Electronic Fuel Injection	Electronic Fuel Injection	Electronic Fuel Injection
Block Material	Cast Aluminum	Cast Aluminum	Cast Aluminum
Head Material	Aluminum	Aluminum	Aluminum
Horsepower Output	403 horsepower	403 horsepower	403 horsepower
Torque Output	417 lb-ft of torque	417 lb-ft of torque	417 lb-ft of torque

GM LS3 Engine Vehicle Applications

LS3 vehicles:

• 2008–2013 Chevrolet Corvette
  • 2008–2013 Corvette Base
  • 2008–2009 Corvette Z51
  • 2010–2013 Corvette Grand Sport
• 2009 Pontiac G8 GXP
• 2010–2015 Chevrolet Camaro SS (Manual Transmission only)
• 2009–2013 Holden HSV (E-Series)
• 2009–2013 Vauxhall VXR8 (GTS)
• 2014–2017 Chevrolet SS
• 2015–2017 Holden Commodore (VF)

L92/L9H/L94 vehicles:

• 2007–2014 Cadillac Escalade (Base, ESV, EXT)
• 2007–2013 GMC Sierra 1500 Denali
• 2007–2009 GMC Yukon Denali
• 2007–2013 GMC Yukon XL 1500
• 2008–2009 Chevrolet Tahoe (LTZ)
• 2008–2009 Hummer H2
• 2010–2013 Chevrolet Silverado 1500
• 2010–2014 GMC Yukon & Yukon XL

L99 Vehicles:

• 2010–2015 Chevrolet Camaro SS (Automatic Transmission only)

GM/Chevy LS3 Engine Design

As we mentioned, the LS3 engine is part of General Motors/Chevrolet fourth generation of small-block V8 engines. It is a 6.2 liter (376 cid) V8, and GM based the block on the Vortec 6200 L92 block, which they introduced a year before the LS3. Unlike most Vortec blocks which are cast iron, GM makes the 6.2 L92 blocks from cast aluminum, like LS-blocks. The LS3 has a bore and stroke of 4.065 x 3.622 in (103.25 x 92 mm), and it is much stronger than the LS2 block it replaced in the Corvette. 

When making the block, Chevy engineers focused on durability and strength. They claim it is just as strong as the LS9 block, which makes more than 600 horsepower from the factory. The bottom is made to be very strong and can take a serious beating. Compression is relatively high at 10.7:1, though the engine is naturally aspirated. 

For the cylinder heads, they are based on the L92 heads but are even higher flowing. According to Chevy engineers, for their time, the heads flowed the most air of any production small-block heads ever made. They had 168 grams/second of intake flow and 123 g/s of exhaust flow. Chevrolet made them from aluminum and they used rectangular D-port style exhaust ports.

Internals

Internally, the LS3 was very robust. The pistons were flat-topped, hypereutectic cast aluminum alloy, with full-floating wrist pins, polymer coating, and an asymmetrical skirt profile. In addition, engineers anodized the top groove of the piston rings for longevity.

The connecting rods were made from powdered metal and were I-Beam style. There are two different styles of crankshaft. Most use a cast iron crank. However, the LS3 Corvette Grand Sport used a forged steel crank due to its dry sump oiling system. 

Valve Train and Intake Manifold

The LS3, like other LS and Vortec series engines, uses a pushrod-actuated overhead valve train (OHV) with two valves per cylinder, for 16 valves total. Unlike the L92 on which it was based, the LS3 does not use variable valve timing. The LS3 has a single camshaft, which is similar to the LS6 camshaft but with 0.25 inch more intake valve lift. 

The complete specs are 204°/211° intake/exhaust duration @ 0.050 in, 0.551/.525 inch intake/exhaust lift, and a 117° LSA. Chevy optimized the valve train for balance, and the intake stems are hollow while the exhaust are solid. 

Compared with the L92 on which Chevy based it, the LS3 used a lower profile and higher flowing intake manifold. They built the manifold from composite material that is light and smooth, but also durable. It also reduces noise through a textured cover. During peak valve-lift, the intake manifold can flow 155 g/s and has optimized runner lengths for performance. 

Compared with the similar LS7 manifold, the LS3 produces horsepower at lower rpm and can flow 90% as well. That might not sound great, but considering the LS7 is 50 cid bigger and makes more than 500 horsepower, it’s pretty remarkable. The LS3 uses a 4-bolt, gold-blade-style, 90mm throttle body. 

The Camaro SS L99 Variant

Chevrolet only produced the L99 for six model years, from 2010–2015 in the automatic transmission Camaro SS. The main differences vs the LS3 are to the valve train, and the L99 had a slightly lower compression ratio at 10.4:1. The camshaft is less hot, with lower 195°/201° intake/exhaust duration and 0.500/.492 in intake/exhaust lift. However, this does help achieve a smoother idle. 

The L99 also has a cam phaser while the LS3 does not, resulting in slightly different pistons with valve-reliefs on top. This is also the cause of the slightly lower compression ratio. In addition, the L99 has both variable valve timing (VVT) and active fuel management (AFM). VVT allows for increasing and retarding of the camshaft timing, which can improve power and aid fuel economy. 

AFM is much more controversial, and is also known as “displacement-on-demand” from some manufacturers. It is a cylinder deactivation technology, which helps improve fuel economy and reduce emissions. It works when the car is being driven at lower loads and the engine does not need as much power. 

The engine’s computer will disable half of the cylinders, which allows for less fuel to be burned. Some people do not mind the technology and appreciate the improvement in fuel economy. But most people dislike the way the engine drives, and it has also been shown to lead to some problems in some vehicles. Check out our sister website Chevy Trucks’ AFM guide for more information about AFM and about potentially disabling it. 

The L92, L9H, and L94 Vortec 6200 Engines

Now, let’s briefly look at the 6.2 Vortec versions of the LS3 engine. The L92 was the first engine, which Chevrolet produced for the 2007–2008 model years. The block was similar but slightly less reinforced than the LS3. The pistons are also hypereutectic cast aluminum alloy, but have valve-reliefs like the Camaro SS L99 pistons. The connecting rods are powdered metal, I-Beam, and the crankshaft is cast iron. 

The L92 and L99 cylinder heads have the same casting numbers and are identical. They also use similar valve trains that are both VVT-capable. The L92 did not use AFM like the L99, though originally Chevrolet included components for it on early versions. The L92, due to its primary use in SUVs and trucks, also uses a less hot camshaft. Specs are 198°/209° intake/exhaust duration, 0.500/.500 in intake/exhaust lift, and an LSA of 115°.

The size of the L92 valves are the same as the LS3, but use solid instead of hollow intake stems. The intake manifold is a higher-profile truck-style manifold with an 87mm silver-blade throttle body.

From 2009–2013, GM introduced the L9H as the replacement for the L92. The L9H was flex-fuel capable with larger injectors, but otherwise had the same specs as the L92, including VVT. From 2010–2014, GM also used the L94 Vortec 6200 variant. The L94 had the same specs as the L92/L9H, and was also flex-fuel capable. However, the L94 also used AFM, unlike either the L92 or L9H, but like the L99 in the Camaro SS. 

GM/Chevy LS3 Engine Reliability and Problems

Overall, most people consider the LS3 engine to be one of the most sturdy and reliable of the entire LS and Vortec-series of small-blocks. Even though they are used in high performance Corvettes and Camaro SS, the LS3 is about as reliable and bulletproof as you can get. In their factory form, they are practically indestructible with proper maintenance and driving. Many LS3 engines have made it well over 150,000 miles without issue, and they are very well built. 

Common Problems

The only real concerns that people have raised with the LS3 are related to the water pump and very occasionally the pushrods. Water pumps are known failure points on other LS and Vortec-series engines, so it’s not entirely surprising they also affect the LS3. The purpose of the water pump is to circulate coolant throughout the radiator and engine block, which cools the engine down. If the water pump fails, the LS3 can suffer from skyrocketing oil temperatures and potentially catastrophic failure.

It’s hard to tell when your LS3 water pump is starting to fail, but coolant leaks are one of the easiest ways to tell. The LS3 is not generally prone to coolant leaks, so if you see one there is a good chance it’s from the water pump. Some water pumps last 200,000 miles, and some crap out after just 50,000 miles, it’s impossible to know when they will go. Making sure you are keeping an eye on coolant and oil temperatures and for potential leaks is the best way to be proactive. 

The other issue is related to pushrods, which can occasionally get bent. The main cause of bent pushrods is from mechanically over-revving, either from an improper downshift or from tuned engines without rpm-limiters. It’s not really an endemic problem to the LS3, and can happen on any pushrod engine. 

Besides pushrods and water pumps, the LS3 is an amazingly stout and reliable chevy engine. Even when modded at lower power levels, these engines can still last for a very long time and stand up to some abuse. 

LS3 Crate Engines, Performance, and Mods

Now for the exciting part: LS3 performance and engine mods/upgrades. From the factory, the LS3 pumps out 426–436 horsepower and 420–428 lb-ft of torque. The nearly identical L99 in the Camaro SS is less powerful, but still delivers 400 horsepower and 410 lb-ft of torque. Inside the 2011 Corvette Grand Sport, the LS3 produced 430 horsepower and 424 lb-ft of torque. That was good for a blazing zero to 60 mph time of just 4.2 seconds. The same Corvette also did the ¼ mile in 12.6 seconds @ 115 mph. 

Comparably, the 2010 Camaro SS with the L99 produced a solid zero to 60 mph time of 4.8 seconds, and did the ¼ mile in 13.3 seconds @ 107 mph. The LS3 powered Camaro SS of the same year was only slightly faster, with the same zero to 60 mph time, but it did the ¼ mile in 13.0 seconds @ 111 mph. While not quite as fast as the LS3, the L99-powered automatic transmission Camaro SS still held its own at the drag strip. 

Today, though it is no longer in production vehicles, GM still sells crate LS3 engines. These range from 450-533 horsepower versions, and come with a variety of camshaft options. There are also carbureted LS3 crate engines without EFI for builders who prefer the old-school fueling method. 

One of the most popular LS3 crate engines is the LS376/480 hot-cammer. This LS3-crate engine uses a LS Hot Cam, which has 0.525/.525 intake/exhaust lift and 219°/228° intake/exhaust duration. Though there is less intake lift than stock, the longer duration more than makes up for it and allows for a ton of airflow. Together, this combines to produce 495 horsepower and 473 lb-ft of torque. 

The Top Bolt-on LS3 Mods

For those of you looking to get some extra power out of your Camaro SS, Corvette, or other LS3-powered vehicles, we have a ton of great LS3 upgrade articles for you. For those looking at basic bolt-ons, we have a 5 best Chevy LS3 engine upgrades article, which has information on tuning, cylinder heads, long-tube headers, x-pipes, and camshaft upgrades. 

In addition, we also have a specific LS3 supercharger guide, LS3 camshaft upgrade guide, LS3 intake manifold upgrade guide, and an LS3 throttle body upgrade guide. The LS3 responds very well to all of these mods, and they can give you gains ranging from just a few horsepower to more than a few hundred. 

For those of you with Corvettes, with a specific LS3 Corvette C6 headers guide. Camaro SS drivers will get some good mileage out of our Camaro SS tuning guide (2010–2023), which also includes tuning info on the fifth generation small-block 6.2 liter LT1 V8 engine. The LS3 is one of the most moddable small-block V8s out there, and they are capable of some serious performance. 

Chevy LS3 Engine FAQ