Beginners Guide to Buying an LS Engine

an LS Engine

Did you know that the LS engine, commonly known as a crate motor, came out way back in 1997 when it debuted in the C5 Corvette? Since then the motor has gained cult status all over the world and still to this day is used in a variety of applications throughout the world.

A wide variety of vehicles used the LS motor but many people don’t know how to choose the right one for them. Read on below and get all the info you could ever want on the LS engine series.

History of the LS Engine

Before you can choose what LS engine you want to buy, you have to understand a little bit about the history of the engine. There are now two distinct generations of the engine, spanning over 20 years of production.

In both, these generations is a universe of engines that, although share common similarities, a fair number of differences can affect what they are used for, how much you pay for the engine, how expensive parts will be, and how easy the actual engine will be to find.

Generation 3

The first small-block V8 engine featured in the Corvette C5 and GM used a lot of similar features of its previous small block designed in 1950 with the same bell housing pattern which made it easier to swop into older generation V8 vehicles. They used two valves per cylinder as well as the same pushrod technology as before.

The major difference you found in the LS1 was that it had a full cast aluminum block and not an iron block. This small change dramatically reduced the engine weight. The next change was that they used an updated electronic distributor and not a traditional one. The cubic inches were lowered to 346 and not the traditional 350.

Gm further expanded the Gen 3 to include a variety of applications and designs. The LS6 came out for two years and was found on the Cadillac CTS-V and the Z06 Corvette.

Further to that, GM produced other iron block LS engines with aluminum cast heads under the Vortec name and included displacements of 4.8 L (LR4), 5,3 L(LM7, L59, LM4), and a 6,0 L (LQ4, LQ9, LS6). Starting in 1999 and running until 2007, these engines supplied a wide range of horsepower from 255 all the way to 345. 

More significantly, they were famed in the racing world because they could handle a significant amount of extra power with their iron blocks. The 4.8 liters and 5.2 Liter both share the same block, which makes part interchangeability easy and is the most popular of engines.

The most common variant, therefore, is the 5.3-liter LM7 engine, and the most powerful motor in stock form is the 6.0-Liter LS6 with 400 HP.

Generation 4

It didn’t take long for GM to decide on a new generation of the LS engine and up-stepped generation 4. GM focused on what had worked on the Gen 3 while adding modern electronic features to further improve the engine.

The first major upgrade saw a variable timing feature on the engine as well as an active fuel management system was put in place to shut off half of the V8s cylinders under light load to become more fuel-efficient.

Electronic throttle control came standard on the Gen 4 while only later engine models in the Gen 3 sported this feature. By 2005, the 6.0-liter LS2 hit the scene with both an aluminum head and block, which helped up the power to 400 horsepower straight out of the factory.

The LS2 soon became GM’s go-to engine and featured in many of its prominent models. By 2006 the engine bore and stroke were further expanded and the LS3 appeared in the Corvette with a stronger aluminum casting and larger ports. The horsepower of the LS3 was then around 430 horsepower. GM would further expand the engine, continually raising the displacement all the way up to a 7.0-liter LS7 engine.

Not only focusing on the power side of the engine, the most popular variations of the Gen 4 engine can be found in GM trucks of the time. GM maintained the 4.8-liter and 5.3-liter units, which produced around 320 horsepower.

A word of warning if you are thinking about using generation 4 in an engine swap. The variable valve timing can be problematic in the long run, which can lead to valvetrain issues that are expensive to repair. You can, however, program out the variable valve timing, but delete kits can be expensive.

Which LS Engine Should I Use?

The best LS engine choice to use right now is the LS3 engine. If you want a turn-key crate engine, it’s hard to go wrong with the tried and tested LS3. With the 400 horsepower standard and 426lb-ft of torque, it is a good base to start off with, if you are thinking of swapping an engine out or building a vehicle, there are many LS engines for sale.

On the market, there is an unlimited supply of LS3 engine parts, modification kits, tuning kits and if you want to go the turbo or supercharger route there are pre-fabricated parts that will make the build easier and cheaper. A supercharger can run up your horsepower to 800 and can be done with the standard internals of the LS3 engine.

Faster and More Powerful

There is no denying it, swapping out your old, outdated V8 for a new LS engine would be the smartest thing you could do all summer. The added power will not only get you from A to B faster but will improve your fuel consumption and make sure you have the latest engine technology available at your disposal. With so many aftermarket and replacement parts, an LS engine upgrade is now as cost-effective as ever.

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