LS3 vs. LS7 Engine: Which is Better for a Truck?

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LS3 is a type of engine used in some Chevrolet models. It stands for “Luxury Sport 3.” It was first introduced in 2009 and continued production until 2015. The LS3 is a 6.2-liter V8 engine that produces 426 horsepower and 420 lb-ft of torque.

LS7 is a high-performance 7.0-liter V8 engine used in some Chevrolet and GMC models. It produces 505 horsepower and 470 lb-ft of torque, making it one of the most powerful engines in its class. LS7s are known for their high revving capability and impressive fuel economy.

LS3 Engine
Sources: https://www.chevrolet.com/performance-parts/crate-engines/ls/ls3

The difference between LS3 VS LS7

Horsepower (HP):

The LS7 is a 7.0L engine that produces 505 hp and 470 lb-ft of torque.

The LS3 engine has a displacement of 6.2 liters and produces 430 horsepower.

Camshaft duration (LS3 VS LS7):

The LS3 camshaft duration is 230 degrees. This is shorter than the LS1 and LS6 camshafts, which have durations of 234 and 236 degrees, respectively. The shorter duration allows for more overlap, which results in improved idle quality and increased torque.

The LS7 camshaft is a great choice for a camshaft in a high-performance engine. It has a duration of 224 degrees, which is ideal for engines with high compression ratios. The camshaft also has a lobe separation angle of 112 degrees, which helps to improve torque and fuel economy.

Maximum Recommended RPM:

The LS3 engine has a maximum recommended rpm of 6,600. This is based on the engine’s design and intended use. Going beyond the recommended rpm can cause damage to the engine.

The LS7 engine is designed to operate up to 7,000 rpm. However, the engine’s power and torque peak at 6,500 pm, so it is recommended to operate at or below 6,500 rpm to maximize its performance.

Connecting rods:

LS3 Connecting rods- LS3 connecting rods are made from forged metal and are designed to handle high horsepower and torque. They are also precision machined and balanced to ensure smooth operation.

LS7 Connecting rods- LS7 connecting rods are made from titanium alloy and have a weight of 631 grams. They are designed for high-rpm applications and can handle up to 7,600 rpm.

Reluctor Wheel:

The LS7 and LS3 engines use a different reluctor wheel than the other LS engines. The LS7 and LS3 reluctor wheel have 58 teeth, while the other LS engines have 24 teeth. This difference between LB3 and LB7 is in the number of teeth that causes the camshaft position sensor to generate a different signal, which the engine management system uses to determine engine speed and timing.

Recommended Fuel:

It depends on some features, such as the specific engine configuration, driving habits, and climate. However, The LS7 engine is designed to run on premium fuel (91 octanes or higher), while the LS3 can typically run on regular fuel (87 octanes).

Pistons:

The LS7 and LS3 engines use different pistons. The LS7 engine uses a forged piston, while the LS3 engine uses a cast piston.

Valve Size:

The LS7 and LS3 engines both use a 6.2-liter displacement, but the LS7 uses a larger valve size. The LS7 has a diameter of 2.20 inches, while the LS3 has a diameter of 1.88 inches. This difference in valve size allows the LS7 to produce more power and torque than the LS3.

LS3 Engine vs. LS7 Engine Specification

Specs LS 3 Engine LS 7 Engine
Part Number 19369326 19329246
VIN code W E
Generations IV IV
Years offered 2008-17 2006-15
Camshaft Duration 204° intake / 211° exhaust 211° intake / 230° exhaust
Rocker Arms EX Investment-cast, roller trunnion Investment-cast, roller trunnion
Maximum Recommended rpm 6600 7000
Cylinder Heads Aluminum L92-style port; “as cast” with 68-cc chambers CNC ported LS7-style ports; 70-cc CNC combustion chambers
Engine Type LS-Series Gen-IV Small-Block V-8 LS-Series Small-Block V-8
Connecting Rods Powdered metal Forged titanium
Reluctor Wheel 58X 58X
Balanced Internal Internal
Recommended Fuel Premium pump Premium pump
Block Cast aluminum with six-bolt, cross-bolted main caps Cast aluminum with six-bolt steel main bearing caps
Rocker Arm Ratio 1.7:1 1.8:1 (offset, intake only)
Camshaft Hydraulic roller Hydraulic roller
Pistons Hypereutectic aluminum Hypereutectic aluminum
Rocker Arms In Investment-cast, roller trunnion Investment-cast, roller trunnion
Displacement 376 (6.2L) 427 (7.0L)
Valve Size 2.165 intake / 1.590 exhaust 2.200 titanium intake / 1.610 sodium-filled exhaust
Compression Ratio 10.7:1 11.0:1
Valve Lift 551 intake / .522 exhaust 593 intake / .588 exhaust
Crankshaft Nodular iron Forged steel
Bore x Stroke 4.065 x 3.622 (103.25 x 92 mm) 4.125 x 4.000 (104.8 x 101.6mm)
Power (hp) 426-436 @ 5900 505 @ 6300
Torque (lb.-ft.) 420-428 @ 4600 470 @ 4800
Size (L) 6.2 7
Fuel type 93rec 91
Bore Size 103.25 mm 104.8 mm
Stroke Size 92 mm 101.6 mm
Block and Heads Material Cast aluminum Cast aluminum
Fuel System Sequential fuel injection Sequential fuel injection
Oil System Dry-sump Dry-sump
Cooling system Water-cooling Water-cooling
Sources

LS3 Tech Specs

LS7 Tech Specs

LS3 vs LS7 reliability

Reliability depends on driving habits, maintenance schedule, and quality of parts used. However, the LS7 engine is generally considered more reliable than the LS3. This is largely due to the LS7 is a dry-sump engine, while the LS3 uses a wet-sump system.

LS3 engines have a long history and have been used in more applications. LS7 engines are newer and have not been used as extensively.

In short, both engines are known for being relatively reliable. The LS7 is a more powerful engine and is often used in high-performance vehicles. However, the LS3 is also a very capable engine and can be found in many popular sports cars. Ultimately, the choice between these two engines will come down to personal preference.

LS7 Engine
Sources: https://www.chevrolet.com/performance-parts/crate-engines/ls/ls7

LS3 vs LS7 weight

The LS3 and LS7 engines weigh about the same. The LS3 is a 6.2L engine, and the LS7 is a 7.0L engine.

Due to the titanium tubes and lighter Pistons, the relationship between the ls7 valvetrain and stability and the rotating assembly is greater. When speaking about the overall weight of a block of titanium weighing in at 450lbs, I doubt a few ounces will make it feasible.

Get into your vehicle, and you’ll save more weight than what Ti valves and pistons save you.

LS3 vs LS7 for boost

Thinking of a Camaro with an LS3 or LS7 with a supercharger? You must need to make 650 to 700RWHP. Which is cheaper and cost-effective? On top of that, which is arguably more reliable?

For example, does building an LS3 (10 to 12 pounds heavier with boost) or an LS7 with a supercharger makes that power better?

In case you Forge your vehicle’s LS3, you will effortlessly reach your power goals. If you just live a gentle increase, your ’69 live long, giving you a slew of smiles.

My friend has a ’69 Camaro in his garage. I wish I had swapped in an LS2 or 3! Hindsight is 20-20. It looks like you are going about it the right way.

In between a forged LS3 versus a stock LS7, choose the LS3. Plus, LS7 would be the best option between the LS3 vs. a stock LS7.

How much psi needs to make 650rwhp with or without a cam?

I made a torque of 640 who at 7 lbs/in of torque on an LS3 A6. I had cam and carbon dioxide emissions.

LS3 vs LS7 heads

A lot of debate over the best LS head for performance! Some people swear by LS3 heads, while others prefer LS7 heads. In general, LS3 heads are considered more street-friendly, while LS7 heads offer more performance potential. Ultimately, it comes down to one’s preference and what you are looking for ahead.

LS3 vs LS7 lifters

The LS3 and LS7 engines use different lifters. The LS3 uses a hydraulic roller lifter, while the LS7 uses a solid roller lifter. The LS7’s solid roller lifter is designed to handle more RPMs and is, therefore, more durable.

LS3 vs LS7 intake manifold

There is no clear consensus on which intake manifold is better – the LS3 or LS7. Some people claim that the LS7 manifold offers better airflow and performance, while others say that the LS3 manifold is more efficient.

But, what’s our observation here?

The LS7 manifold is taller and has a larger plenum than the LS3. This allows for more airflow and improved performance. The LS7 manifold also has a different throttle body mounting position, which can cause fitment issues on some vehicles.

LS3 vs LS7 throttle body

The LS3 and LS7 throttle bodies are both designed to work with the Corvette’s electronic throttle control system. The LS3 throttle body is a single-blade design, while the LS7 throttle body is a dual-blade design. The LS7 throttle body is larger than the LS3 throttle body and is said to provide improved airflow and performance.

LS3 vs LS7 block

The LS3 and LS7 blocks are very similar, but there are a few key differences. The LS7 block is made from a higher quality aluminum than the LS3 block, and it has a thicker deck. This makes the LS7 block stronger and more resistant to warping.

LS3 vs LS7 injectors

The LS3 and LS7 injectors are both high-flow injectors, and the LS7 injectors are the same. The LS3: LS7 injectors fill at 41.74 psi while engines are running at 58 psi gauge pit fuel pressure.

Supercharged LS3 vs LS7

The LS3 is a supercharged engine, while the LS7 is a naturally aspirated engine. The LS3 is more powerful, but the LS7 is more efficient. On the other hand, The LS7 is more powerful and has a higher rev limit, while the LS3 is more fuel-efficient. Ultimately, it comes down to personal preference.

Audio research LS3 vs LS7

Generally speaking, the LS3 model is a bit more compact and affordable than the LS7, making it a good option for those who need portability or are on a budget. However, the LS7 offers better sound quality and more power, making it a better choice for larger spaces or more demanding applications.

LS3 Stroker vs LS7

The LS3 stroker is less expensive and has more torque, while the LS7 is more powerful and has a higher redline. Ultimately, the best choice depends on your individual needs and preferences.

FAQ:

What vehicles came with an LS3?

The Chevrolet Camaro SS, the Cadillac CTS-V, and the Chevrolet Corvette all come with an LS3 engine.

What car has an LS7?

The Chevrolet Corvette, the Cadillac CTS-V, and the Dodge Viper all have an LS7 engine.

How much is an LS3 engine?

An LS3 engine typically costs between $5,000 and $8,000, depending on the vehicle’s year, make, and model.

Can LS7 handle boost?

The LS7 engine can handle boost, but it is not recommended. Boost can increase the stress on the engine and cause damage.

How much horsepower does a supercharged LS7 have?

The LS7 engine is a 7.0-liter V8 that produces 505 horsepower and 470 pound-feet of torque in its stock form. When supercharged, it can produce up to 650 horsepower.

Wrapping up

There is no clear answer as to which engine is better, the LS3 or the LS7. Both engines offer great performance and power, but the LS7 does have a slight edge. It has a higher displacement and produces more power than LS3. However, the LS3 is more fuel-efficient and may be a better choice for those who are looking for a more economical option.

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