LQ9 vs LQ4

The difference between the LQ9 & the LQ4 pistons (Answered)

The main difference between the LQ4 and the LQ9 engine is the pistons and LQ9 have high static compression ratio. Except for this component, the engines are quite similar to each other. The piston of LQ4 is dished but it is flat in the LQ9 engine. This smooth and flat-surfaced piston ensures a higher compression ratio in LQ9. Hence, there is also a difference in power in LQ4 vs. LS9 where LQ9 stands superior.

lq4 piston

How to tell the difference between LQ4 and LQ9

1.   Visual Distinctions

Any specific visual identification between the two engines is very hard. It is because the difference lies in the pistons and wrist pin rods. These components are part of the engine’s rotating assembly and are kept closed off inside the engine block. Then again, you can remove the spark plug and inspect the cylinder using a flashlight or borescope. If it is dished, then it is an LQ4.

2. Replacement

The LY6 engine was first introduced back in 2007 as a replacement for the LQ4 engine. This engine was one of the very first 4th generation LS truck engines. The LY6 engine had Variable Valve Timing (VVT). It assisted in generating more horsepower and torque compared to that of the previous 6.0L engines.

3. Price Considerations:

Both the engines cost around $1500, excluding any other additional components but the engine block only. The LQ9 is a limited production engine, so it often comes with a premium of $1000. Then again, if you can afford the premium of $1000, you can get an LQ4 instead and attach additional modifications at a comparatively lower cost.

4. Transmission Considerations:

The rating of the chassis indicates the payload capacity of a truck. A 1500 chassis truck has a payload capacity of half a ton, 2500 has three-quarter-ton, and finally, a 3500 has a payload capacity of one ton. The notable fact here is that the transmission comes based on the payload capacity of the vehicle, based on horsepower. So, any truck or SUV with 1500 chassis will get L460E transmission, and there will be L480E for any trucks with 2500 chassis. The transmissions, L460E and L480E, are not electrically interchangeable.

Similarities in Design: LQ4 and LQ9

●     Engine type- Both the engines, LQ4 and LQ9, are small block engines. These engines have smaller bores and shorter strokes, resulting in less displacement than big-block engines. The displacement is typically less than 400 cubic inches.

●     Performance- When it comes down to comparing LQ4 vs. LQ9, both the engines show similar promising results. The motor can generate great horsepower and handle different types of modifications such as high-flow cylinder heads, superchargers, turbos, cams, intake systems, and nitrous oxide.

●     Components inside- Excluding the pistons, all the engine blocks’ components are identical to each other. The diameters and sizes also match up, such as connecting rod length, intake port shape, bore spacing, deck height, stroke, bore diameters, and so on.

●     Availability- The engines became popular and used in a huge number of cars till production date. Hence, the engine blocks and the essential additional components are readily available in the market. Not only the instruments and components for these engines but also fine-tuning guides are also available for self-adjustments.

About LQ4 Engine

The LQ4 is a 3rd generation, 6.0L small-block engine produced by General Motors. The engine was used from 1999 to 2007 in GM trucks before getting replaced by its successor. The engine was also recognized as Vortec 6000 for marketing purposes.

LQ4 pistons

The engine wound up in almost every brand car under General Motors, including Chevy, Pontiac, Cadillac, GMC, Buick, and so on because of its solid build and performance. It can be upgraded with turbos and superchargers as well. Though the modification requires forged internals, the cost is totally worth it.

As the engine is built with a wide variety of options for modifications, the car can be used for several purposes. Hence, a variety of working people go for this engine.

LQ4 build: The LQ4 engine, referred to as Vortec 6000 by General Motors, is a small block engine featuring 300 to 325 horsepower and 360-370 foot-pounds of torque based on the type of cylinder heads used. The engine is well built to handle greater horsepower with modifications such as turbos, superchargers, nitrous oxide, and such.

LQ4 cam: The LQ4 cam gear attachment has three bolts. The cam helps to generate more torque. Hence, there is a noticeable improvement in performance after the correct cam adjustments.

LQ4 block: The block of the LQ4 engine uses iron material. The diameter of the bore is 4 inches, and the stroke is 3.622 inches. It has a bore spacing of 4.40 inches. The main cap has a 6-bolt style.

LQ4 heads: The heads were initially made up of iron, but later on, aluminum was used. It has a cathedral intake port. The shape of the exhaust port was initially oval, but in the later versions,D-ports were used.

6.0L Vortec 6000 Engine Specs (LQ4, LQ9, L76, LY6):

 LQ4 Specification:

6.0L Vortec V8 Engine SpecsLQ4
Horsepower:300 hp @ 4400 RPM
Torque:360 lb.-ft. @ 4000 RPM
Bore and Stroke (in / mm):4 x 3.62 / 101.6 x 92
Compression Ratio:9.4:1

  LQ9 Specification:

6.0L Vortec V8 Engine SpecsLQ9
Horsepower:345 hp @5200 RPM
Torque:380 lb.-ft. @4000 RPM
Bore and Stroke (in / mm):4 x 3.62 / 101.6 x 92
Compression Ratio:10.1:1

   L76 Specification:

6.0L Vortec V8 Engine SpecsL76
Horsepower:354 hp @ 5600 RPM
Torque:376 lb.-ft. @ 4400 RPM
Bore and Stroke (in / mm):4 x 3.62 / 101.6 x 92
Compression Ratio:10.4:1

  LY6 Specification:

6.0L Vortec V8 Engine SpecsLY6
Horsepower:353 hp @ 5400 RPM
Torque:373 lb.-ft. @ 4400 RPM
Bore and Stroke (in / mm):4 x 3.62 / 101.6 x 92
Compression Ratio:9.6:1

About LQ9

For specific details about LQ9 engines, please follow the links below:

.           Chevy LQ4 Engine Specs

.            Chevy LQ9 Engine Specs

.            Upgrading the LQ4 and LQ9 Engines

The LQ9 is a 3rd generation, 6.0L Vortec engine built on a small block V8 platform. It is the successor of the LQ4 engine with some added modifications. The distinction was more evident in the compression ratio and piston design for the LQ4 vs. LQ9 upgrades.

The flat surface piston in LQ9 ensures a compression ration of 10.1:1. Hence a higher horsepower is generated compared to that of LQ4. Overall, LQ9 provides a distinct performance boost over the LQ4.

Although it has a great performance within affordable price, there is one drawback. The engine weighs over 200 pounds which makes it difficult to handle.

LQ9 pistons- The pistons are the most distinguishable feature of an LQ9 engine compared to an LQ4. The piston of the LQ9 engine is flat-topped with a smooth surface. This design increases the compression ratio compared to that of its predecessor, LQ4. As a result, the stock horsepower also increases.

lq9 pistons and rods

LQ9 block- The lock material used for the LQ9 is iron. It has a bore diameter of 4 inches and a stroke of 3.62 inches. The engine block has a 6-bolt main cap style. The block is well built to accommodate more horsepower with engine modifications.

LQ9 crate engine- Crate engines are completely customized, ready to drop in engines with high performance than the factory original. In the case of LQ9, a variety of customization options are available. In each case, modifications like forged pistons, hydraulic cams, and such assist in reaching peak horsepower and torque.

LQ9 build- The LQ4 engine has a solid build and is very popular among the masses. It can withstand extreme modifications for higher performance as per the owner’s desires. It delivers decent results for general use at an affordable price, and with proper modifications, it becomes beastly.

LQ9 stroker kit- The stroker kit helps to increase the internal strokes of the engine. It is the distance covered by the piston inside the cylinder bore of the engine. As the piston covers more distance, the crankshaft rotates faster and hence, generates more power.

LQ9 rebuild kit- Rebuild kits for the LQ9 engine are readily available in the market at an affordable price range of $800 to $1000. The rebuilding kit includes a complete gasket set with seals, pistons, rings, rod bearings, main bearings, cam bearings, oil pump, and timing kit. As a widely used engine, the rebuilding guide is also available for those who want to do it themselves.

LQ9 cam kit- By using the right camshaft kit, you can increase the engine’s horsepower by a significant number. The increased horsepower results in better performance of the engine. Cam kits come in three stages, each designed for specific user demands. Emission-compliant cams are also available in the market. The price stays between an affordable range of $1000 to $1200.

LQ9 weight- the LQ9 is durable because of its solid build, but the downside is the weight. Just the engine block weighs about 100 pounds. With upgraded internals, the weight can increase up to 220 pounds.

LQ9 Specification- Boasting 345 horsepower at 5200 RPM, the LQ9 meets the demand of almost all general users. Its solid build, ability to accommodate upgrades, the affordable budget also attracts car enthusiasts who want better performance within the budget.

LQ9 upgrades- With some additional upgrades, you can boost the performance of your LQ9 stock engine. Adding a cold air intake kit, headers, aftermarket exhaust, and a computer programmer upgrade can enhance fuel economy and performance.

6.0 LQ9- The 6.0L 3rd generation LQ9 is a small block engine used in many cars. The engine provides a decent performance within an affordable budget, meeting the needs of a wide range of customers.

Chevy LQ9- The Chevy LQ9 engine is used in widely used cars such as Cadillac, Chevrolet, and GMC. It has a compression ratio of 10.1:1, it exceeds its predecessor in performance by generating higher power. The flat surfaced pistons ensure a higher power output.

Pistons 6.0L Genuine GM Flat Top (Brand New Set of 8) LS2 LQ9

Pistons 6.0L Genuine GM Flat Top LS2 LQ9


Is an LQ4 an LS motor?

The engines are mechanically similar and have gained huge popularity. It has also become the go-to performance engine. The engines can also be swapped with each other when needed. General Motors cars such as the GMC, SUVs, and such use these engines frequently because of their functionality, availability, and popularity.

Is LQ4 better than LS1?

The engines have the same bore and stroke, but there are some differences. The LS1 has dished pistons, whereas the LS1 has smooth, flat ones, which provides a higher compression ratio. A higher compression ratio also ensures greater horsepower and torque. Hence, performance in LS1 is also better. The rods in the LS1 are better compared to that of the LQ4 too.

Can I put 243 heads on LQ4?

Yes, you can put 243 heads on LQ4, and it will be a great move to do so. There will be a decent increase in the compression ratio, and it will help quite a bit in driving. The head flow is almost the same, but the compression rise is reason enough to use 243 heads.

Are 5.3 and 6.0 heads the same?

All the GM heads of the 3rd generation are interchangeable because these have the same flow characteristics. This design also ensured abundant availability of the component in the market. Hence, you can swap the heads according to your needs. Then again, to get decent performance, the right engine must be paired up with the correct heads. 

How much HP can you get out of a 6.0L LS?

You can expect to get an HP of 529 out of a 6.0L LS engine at 6800 RPM. It is more than enough power for any general user. The piston in LS is flat with a smooth surface. This design ensures a high compression ratio and, evidently, better performance. Then again, to get the most out of the engine, you should get forged internals for the engine.

How long do Chevy 6.0 engines last?

Chevy 6.0 engines easily make past the benchmark of 200,000 miles and often reach 300,000 miles or more. The engines regularly make it to the list of long-lasting vehicles. Regular servicing and proper care increase the longevity of the engine by a great margin. Hence, you can expect it to last for 10 to 20 years very easily.

How much boost can a stock LQ4 handle?

The engine has a very solid build, so it can easily handle horsepower of more than 1000. You can use superchargers, turbos, and nitrous oxide for higher performance, but upgrading the internals is suggested. Then again, changing the pistons increases the compression ratio to generate more horsepower and torque. By using a cam kit, the horsepower further reaches a new peak with even better performance.

Is an LQ4 an LS1?

Yes, the LQ4 engine was first introduced in the LS trucks back in 1999, and it was in production till 2007. The GM pick-ups, SUVs, and vans had these engines in them. There are several generations of the engine. Each generation varies with the other either in building materials or in performance. But it got better consistently from the first to the later generations.

How do I get more power out of my LQ4?

You can add several modifications to the engines, namely a cold air intake kit, headers, aftermarket exhaust, and a computer programmer. These modifications will increase the performance of the engine, but you should also get enforced internals. Changing the pistons for increased compression ratio and camshaft for more horsepower also boosts the engine’s performance. You can change the compression ratio by changing the pistons as well to generate more power.

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