LS1 vs LS6 Engine Heads

LS1 vs LS6 Engine Heads
LS1 vs LS6 Engine Heads

Comparison between LS1 and LS6 is the most common argumentation among the engine heads of the LS series. No wonder, both work great based on their budget and construction. Still, it is demanded by many customers to place them side by side and evaluate them in terms of performances. Intending to help the worldwide users, we have tried our best to conduct a completely neutral and practical test on both of the cylinder heads.

Why Compare

As we have already mentioned, both LS1 and LS6 have some similarities as they are members of the same family. So, clients often get confused about which one to buy. They wonder which will best fit their needs and which will serve the engine the best. Also, what exact disparities make them two different heads. Without a forthright confrontation, these questions will remain unanswered. So, we have tried our best to solve the puzzle. How about giving a quick glance at the comparison table below?

LS1 vs LS6 Comparison

Compression Ratio 10.2:1

Compression Ratio 10.5:1

Horsepower Rating 305-350 hp

Horsepower Rating 385-405 hp

Torque Rating 335-365 ft./lbs

Torque Rating 385-400 ft./lbs.

Bore Size 3.89"

Bore Size 3.89"

Combustion Chamber Volume 67 cc

Combustion Chamber Volume 65 cc

Intake Valve Diameter 2.000"

Intake Valve Diameter 2.000"

Intake Runner Volume 200 cc

Intake Runner Volume 210 cc

Exhaust Runner Volume 70 cc

Exhaust Runner Volume 75 cc

Exhaust Port Shape Oval

Exhaust Port Shape D-Port

LS1 Short Review

This is the first cylinder head from the LS platform. It was launched in the year of 1997 and designated as Gen lll. The most amazing specialty of the LS designs is the interchangeability among them. This is no exception, fortunately. However, the latest firing order helps it to have a unique sound in comparison with its Gen l and Gen ll products.

Making its debut in the 1997 Corvette and moving to the Camaro in 1998, it really came across a long way till date. The very first engine was 5.7 L, 346 ci.

The latest version includes a deep skirt block, an aluminum block, and a coil near plug ignition as well. Initially, the Camaro rated LS1 at 305 hp. Both the Camaro and the Corvette versions were provided with less-satisfying perimeter bolt valve cover heads.

In 1999, there was a center bolt design provided. This was the beginning which is being continued in all other posterior LS variants. The intake port shape is cathedral having a 200 cc intake runner volume. It features 67 cc combustion chamber volume along with a 2 inches intake valve diameter. The cylinder head bolt style is torque to yield.

Talking about the exhaust feature, the valve diameter is 1.550 inches, the exhaust runner volume is 70 cc, and the port shape is oval. You will find the casting number in the corner of the head. The most common casting number is 241, used in most of the LS1. Still want to know more about LS6 then check out the ls3 vs ls6 article.

LS6 Short Review

The very next version of the LS platform is the LS6. This was basically an improved version of its ancestor, LS1. So, it naturally outperforms the LS1 in many sectors like power, pistons, compression, strength, etc. Just like the other evolving LS engines, this version also equally satisfies the users by freeing up the ports for maximizing airflow.

Both LS1 and LS6 can run only cathedral port heads. Like the other heads, the head bolt pattern is also the same. It featured four bolts per cylinder that are 11 mm. In the upper row, there are five 8 mm bolts. Like the previous one, it had different bolt sizes. But the issue got fixed back in 2004. Reviewing the cylinder head bolt size we found that from 1997-2003 they were (8) M11 x 2 x 155, (2) M11 x 2 x 100, (5) M8 x 1.25 x 45.

In 2004, it changed to (10) M11 x 2 x 100, (5) M8 x 1.25 x 45. One of its most unique features is the hollow stem valves, made of stainless steel. Now it’s time to specifically know about the specifications. Well, it is a revised and elevated product. So, the specs are certainly wisely input.

The combustion chamber is 65 cc in volume. We loved the cathedral intake port along with the 210 cc intake runner volume. The exhaust port is D-shaped having a 75 cc exhaust runner volume. This Gen lll powerful 5.7 L LS6 engine features a head of the same intake and exhaust valve diameter as the LS1 heads.

Difference Between LS1 & LS6

So what did we find after going for such an intense investigation? Obviously, the answer is in the previous description. As the latter is the developed version, obviously it will be a better option. But, they resemble each other a lot. Many features are identical as well. The major change was in the intake port. In order to eliminate the airflow issue, the short-run radius was changed in the LS6 heads.

Another distinction is in the combustion chamber. The latter features a lower chamber, reduced chamber size, and an increased CR. Like many racing cylinders, the LS6 uses a D shaped exhaust port to increase the consistency of the cross-sectional areas. Moreover, a better flow on both the intake and exhaust side is waiting for you if you are considering an LS6 head as the replacement of an LS1 head.

Final Words 

LS is a leading name in the industry. The original LS cylinder heads are the most important key to distinguish them from others in terms of airflow and power level. Both the engine heads discussed above are similar to a considerable extent. The latter is an upgraded version in some specific aspects. However, you can anytime change or replace one another to run your engine best. So what’s your thought of this LS1 VS. LS6 debate? Don’t forget to share.

Frequently Asked Questions (FAQ)

An LS6 engine block is equipped with cast-iron cylinder heads. The heads are attached to the block with head bolts. The heads have intake and exhaust ports that are used to bring air and exhaust gases into and out of the cylinders. The heads also have spark plug holes that provide a place for the spark plugs to be installed.
An LS1 engine can have either aluminum or cast iron heads. Aluminum heads are more common, as they offer better cooling and performance. Cast iron heads are less expensive and may be a good choice for some applications.
No, the LS6 is not the same as the LS1. The LS6 is a high-performance version of the LS1 that was used in the Corvette Z06 from 2006-2013. It is a 6.2L engine that produces 505 hp and 470 lb-ft of torque. The LS1 is a 5.7L engine that produces 350 hp and 375 lb-ft of torque.


LS1 Engine

LS6 Engine

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