The LS engines are a family of engines produced by General Motors. LS stands for “Luxury Sport,” These engines were designed with performance in mind. There are a variety of LS engines, including the LS2, LS3, and LS7.
Each motor has its unique features and benefits, and the differences in each of them can determine which engine you want to use in your next build or upgrade your current car.
LS2 engine pros and cons
The LS2 engine is a small block V8 that was introduced in 2004. It is an evolution of the LS1 engine, with a higher compression ratio and more power.
The LS2 was used in various GM vehicles, including the Corvette, Camaro, and Pontiac G8.
Pros
- More potent than the LS1
- Higher compression ratio
- Used in a variety of GM vehicles
Cons
- Some parts are not interchangeable with the LS1
- More expensive than the LS1
LS3 engine pros and cons
The LS3 engine is a small block V8 that was introduced in 2008. It is an evolution of the LS2 engine, with a higher compression ratio and more power. The LS3 was used in various GM vehicles, including the Corvette, Camaro, and Pontiac G8.
Pros
- More potent than the LS2
- Higher compression ratio
- Used in a variety of GM vehicles
Cons
- Some parts are not interchangeable with the LS2
- More expensive than the LS2
LS7 engine pros and cons
The LS7 engine is a small block V8 that was introduced in 2006. It is an evolution of the LS2 engine, with a higher compression ratio and more power. The LS7 was used in various GM vehicles, including the Corvette, Camaro, and Pontiac G8.
Pros
- More potent than the LS2
- Higher compression ratio
- Used in a variety of GM vehicles
Cons
- Some parts are not interchangeable with the LS2
- More expensive than the LS2
LS2 vs LS3 vs LS7: How Do They Differ?
Key differences and similarities at a glance
| Comparing points | LS2 | LS3 | LS7 | Winner |
| Displacement | 6.0L | 6.2L | 7.0L | LS7 |
| Engine material | Aluminum | Aluminum | Aluminum | None |
| Compression ratio | 10.9:1 | 10.7:1 | 11:1 | LS7 |
| Piston stroke size | 3.62? | 3.62? | 4? | LS7 |
| Cylinder bore size | 4.00? | 4.06 | 4.125? | LS7 |
| Torque output | 400 ft-lbs | 425 ft-lbs | 470 ft-lbs | LS7 |
| Power output | 400 hp | 430 hp | 505 hp | LS7 |
| Intake | Cathedral port | Rectangular port | Raised square port | LS7 |
| Exhaust | 1-7/8? headers | 1-3/4? headers | 1-3/4? headers | LS7 |
| Valvetrain | OHV, two valves per cylinder | OHV, two valves per cylinder | DOHC, four valves per cylinder | LS7 |
| Oil system | Wet sump | Wet sump | Dry sump | LS7 |
| Fuel system | Sequential fuel injection (34lb/hr) | Sequential fuel injection (42lb/hr) | Sequential fuel injection (41.7lb/hr) | LS3 |
| Fuel type | Petrol | Petrol | Petrol | None |
| Weight | 517 lbs | 536 lbs | 545 lbs | LS2 |
| Reliability | Reliable | Very reliable | Reliable | LS3 |
| Interchangeability | Some parts are not interchangeable | Some parts are not interchangeable | Some parts are not interchangeable | None |
| Price | $6,000 | $7,000-8,000 | $10,000 | LS2 |
| Generations | 2nd generation | 3rd generation | 4th generation | LS7 |
| Year | 2004-2006 | 2008-2009 | 2006-2009 | LS3 |
| Emission | Emissions compliant | Emissions compliant | Emissions compliant | LS2 |
While there are many similarities between the 3 LS engines, quite a few differences need to be pointed out. These differences make one engine better than the other and depend on what you are going for when building your car.
The LS3 is the high-performance version of the LS engine family. It features an all-aluminum 6.2L (376 ci) engine and produces 430 hp at 5900 rpm and 424 lb·ft of torque at 4600 rpm. The LS3 was introduced in the 2008 Chevrolet Corvette.
The LS7 is the high-performance version of the LS engine family. It features an all-aluminum 7.0L (427 ci) engine and produces 505 hp at 6200 rpm and 470 lb·ft of torque at 4800 rpm. The LS7 was introduced in the 2006 Chevrolet Corvette Z06.
The LS2 is the budget performance version of the LS engine family. It features an all-aluminum 6.0L (364 ci) engine and produces 400 hp at 6000 rpm and 400 lb·ft of torque at 4400 rpm. The LS2 was introduced in the 2005 Chevrolet Corvette.
Here are the specs of each engine and which engine comes out on top in each area:
Displacement
LS2: 6.0L
LS3: 6.2L
LS7: 7.0L
Winner: LS7 because a larger displacement engine usually means more power.
Engine material
LS2: aluminum
LS3: aluminum
LS7: aluminum
Winner: None
All of the engines are aluminum; however, the rods and crankshafts can be made from different materials, so keep an eye out for that when you are working on these engines.
Compression ratio
LS2: 10.9:1
LS3: 10.7:1
LS7: 11:1
Winner: LS7 because a higher compression ratio means more power and efficiency. The LS2 and LS3 are very close, yet the LS3 outputs more power despite having a lower compression ratio due to being a newer and more efficient engine.
Piston stroke size
LS2: 3.62″
LS3: 3.62″
LS7: 4″
Winner: LS7 because a more significant stroke means more power. The LS2 and LS3 have the same stroke size.
Cylinder bore size
LS2: 4.00″
LS3: 4.06″
LS7: 4.125″
Winner: LS7 because a larger bore means more power. The LS2 and LS3 are very close in size.
Torque output
LS2: 400 ft-lbs
LS3: 425 ft-lbs
LS7: 470 ft-lbs
Winner: LS7 because more torque means more power. The LS2 and LS3 are very close, with the LS3 coming out slightly ahead.
Power output
LS2: 400 hp
LS3: 430 hp
LS7: 505 hp
Winner: LS7 because more horsepower means more power. The LS2 and LS3 are close but the LS3 is slightly better.
Intake
LS2: cathedral port
LS3: rectangular port
LS7: raised square port
Winner: LS7 because a raised square port is more efficient than a cathedral or rectangular port.
Exhaust
LS2: 1-7/8″ headers
LS3: 1-3/4″ headers
LS7: 1-3/4″ headers
Winner: LS7 because a larger exhaust means more power. The LS2 and LS3 are very close and are almost the same engine.
Valvetrain
LS2: OHV, two valves per cylinder
LS3: OHV, two valves per cylinder
LS7: DOHC, four valves per cylinder
Winner: LS7
The winner was chosen because four valves per cylinder are more efficient than two valves per cylinder. The LS2 and LS3 are very close and are almost the same engine.
Oil system
LS2: wet sump
LS3: wet sump
LS7: dry sump
Winner: LS7
The winner was chosen because a dry sump is more efficient than a wet sump. The LS2 and LS3 are very close and are almost the same engine.
Fuel system
LS2: sequential fuel injection (34lb/hr)
LS3: sequential fuel injection (42lb/hr)
LS7: sequential fuel injection (41.7lb/hr)
Winner: LS3
All of the engines use a sequential fuel injection system. However, their fuel flows vary, with the LS3 having the most flow and the LS2 having the least flow.
Fuel types
LS2: petrol
LS3: petrol
LS7: petrol
Winner: None
All of the engines take the same kind of fuel. Premium gasoline is what you should put into any of these engines if you want the most power and best efficiency.
Weight
LS2: 517 lbs
LS3: 536 lbs
LS7: 545 lbs
Winner: LS2
The winner was chosen because a lighter engine means better performance with a higher power-to-weight ratio.
Reliability
LS2: very reliable
LS3: very reliable
LS7: very reliable
Winner: LS3 because reliability is an essential factor in engine performance. The LS3 is the newest engine, and with the advances in technology, it should be the most reliable out of the 3.
Interchangeability
LS2: some parts are not interchangeable
LS3: some parts are not interchangeable
LS7: some parts are not interchangeable
Winner: None because interchangeability means that the engine is easier to modify. You will have to look up each part to determine whether or not it is interchangeable.
Price
LS2: $6,000
LS3: $7,000-8,000
LS7: $10,000
Winner: LS2
The winner was chosen because the price is very important when buying an engine. The LS2 is the cheapest engine out of the three.
Generations and years
LS2: 2nd generation, 2004-2006
LS3: 3rd generation, 2008-2009
LS7: 4th generation, 2006-2009
Winner: LS3 because a more recent engine is more efficient.
Emissions
LS2: emissions compliant
LS3: emissions compliant
LS7: emissions compliant
Winner: LS2
All of the engines are emissions compliant but due to the LS2 using the least amount of fuel, it disperses the least amount of emissions. That means you won’t be polluting the air nearly as much as the other two engines.
LS2 vs LS3 vs LS7: What’s best for whom?
The LS2 engine is your go-to choice if you want a robust and reliable engine at a reasonable price.
The LS3 engine is perfect for those who wish to have even more power and are willing to pay a bit more for it.
On the other hand, the LS7 is best for those who want the most power and won’t mind paying a premium.
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