LS Rocker Arm Torque Specs and Sequence

Considering how important of a job the rocker’s arms have, plus how much damage they can cause if they fail, tightening them down to the exact torque spec is of utmost importance. However, there is more to tightening rocker’s arms than just bolt torque specs, but more on that later.

For now, the LS rocker arm torque specs are 22 lb-ft or 30 N•m. That goes for all LS series engines, with the only difference being the LS9 (ZR1), where GM issued a warning that the rocker arm torque must not exceed 24 lb-ft because the aluminum head threads will strip.

LS Rocker Arm Torque Explained

Tightening the rocker arms on your LS engine to the correct torque spec is extremely important, as it is on any engine. However, some LS series engines have had problems with the rocker arm bolts backing out and even stripping the cylinder head threads, which was the case with the LS9 engine.

But before you jump into the torque specs, it’s important you understand that torque sequence is equally important. Torque sequence means you should tighten the bolts in a specific order so that all metal surfaces mate against each other properly.

To do that, you first have to know the LS cylinder numbers. In all LS engines, standing at the front of the engine, the right bank cylinder nearest to you is number 1, the next nearest to you on the left bank is 2, then the next closest to you on the right bank is 3, and so on. You can also find a sea of photos online demonstrating the LS cylinder numbers. After that, you are ready for the LS rocker torque sequence.

Now, before you start with your LS rocker arm install, make sure that cylinder number 1 is at the top dead center of the compression stroke. That means both the intake and the exhaust valve are closed or not on the camshaft lobe.

Once the cylinder is in that position, tighten the exhaust valve rocker arms on cylinders number 1, 2, 7, and 8. Then, tighten the intake rocker arms on cylinder numbers 1,3,4, and 5.

After that, rotate the crankshaft 360° so that cylinder number one is at the top dead center of the compression stroke again. Next, tighten the exhaust valve rocker arms on cylinders number 3, 4, 5, and 6. And lastly, tighten the intake rocker arms on cylinders numbers 2, 6, 7, and 8.

Also, the 5.3 LS rocker arm torque sequence and the 5.3 LS rocker arm torque specs are the same, as well as the 4.8 LS rocker arm torque spec and sequence. Although the 4.8 and 5.3 are called Vortec, they still share the same geometry as LS-Series engines.

Third Generation LS Rocker Arm Torque Specs (1999-2007)

The third-generation Chevy small block only had two variations of the LS engine, both of which can be considered the first-gen LS series. Those two engines are the LS1 and LS6, both of which are 5.7 liters. And although the two engines share few similarities, the LS rocker arm torque spec and sequence is one of them.

LS1

Rocker Arm Torque Specs – 22 lb-ft/30 N•m

Vehicles With the LS1 Engine

LS6

Rocker Arm Torque Specs – 22 lb-ft/30 N•m

Vehicles With the LS6 Engine

Fourth Generation (2005-2020)

The fourth generation is when the LS engines realized their full potential. From the direct replacements for the LS1 and LS6, now called the LS2 and LS3, to the transversely mounted front-wheel drive LS4. Moreover, with this generation, GM introduced their biggest production engine ever, the LS7, and the most powerful production engine, the LS9. But even with all the diversity, the LS rocker arm torque is the same for all fourth-gen LS variations.

LS2 

Rocker Arm Torque Specs – 22 lb-ft/30 N•m

Vehicles With the LS2 Engine

LS3

Rocker Arm Torque Specs – 22 lb-ft/30 N•m

Vehicles With the LS3 Engine

LS4

Rocker Arm Torque Specs – 22 lb-ft/30 N•m

Vehicles With the LS4 Engine

LS7

Rocker Arm Torque Specs – 22 lb-ft/30 N•m

Vehicles With the LS7 Engine

LS9

Rocker Arm Torque Specs – 22 lb-ft/30 N•m

Vehicles With the LS9 Engine

LSA

Rocker Arm Torque Specs – 22 lb-ft/30 N•m

Vehicles With the LSA Engine

FAQs:

How tight should rocker arm bolts be?

How tight rocker arm bolts should be, depends on the engine and vehicle. In some cases, it might be 25 lb-ft; in others, 19 lb-ft, and in all LS engines, it’s 22 lb-ft. But again, it’s important that you know what the torque specs are for your specific engine or car and tighten them accordingly.

How do you tighten rocker arms on an LS3?

To tighten rocker arms on an LS3, set cylinder number one to the top dead center of the compression stroke and tighten the exhaust rocker arms on cylinders number 1, 2, 7, and 8, plus intake rockers on cylinders number 1, 3, 4, and 5. Then rotate the crankshaft 360 degrees and tighten the rest of the rocker arms, exhaust ones first. All rockers should be tightened to 22 lb-ft.

Can you reuse LS rocker arm bolts?

Yes, you can reuse LS rocker arm bolts because they are not TTY (torque to yield). That said, it’s always advised you to replace all internal bolts after removing them 3 to 5 times.

What torque for roller rocker bolts?

The torque for roller rocker bolts usually ranges between 19 lb-ft and 25 lb-ft, depending on the engine. So, it’s extremely important you find the correct torque specs for your specific engine.

What size are LS rocker arm bolts?

LS rocker arm bolts are 8 mm x 1.25. Eight millimeters is the diameter of the bolt, and 1.25 is the thread pitch. The factory bolts are grade 8 steel, but stronger ones are available.

What happens if the rocker’s arms are too loose?

If a rocker’s arm is loose, the valves won’t open and close properly, which leads to poor fuel economy and performance; plus you may hear ticking noises coming from the engine. Also, in the worst-case scenario, the valves could burn or drop into the cylinders, thus destroying the engine.

Are LS3 and LS7 rockers the same?

No, LS3 and LS7 rockers are not the same. The LS3 rockers have a 1.7 ratio, while the LS7 rockers have a 1.8 ratio. That means the LS7 rockers will have a higher valve lift on the same camshafts. Also, the rockers are different shapes, so they are not interchangeable.

Do rocker arms increase HP?

Yes, rocker arms can increase HP. Rocker arms have a ratio, for example, 1.5, which means they lift the valves 1.5 times the height of the camshaft lobe. If you were to install rocker arms with a 1.6 ratio, you would get the same result as you would with high lift cams and get more horsepower.

What do you torque rocker arms to?

What you torque rocker arms to depends on your engine and can be anywhere between 19 lb-ft and 25 lb-ft. However, it’s important to tighten them to the correct torque specification, which means getting the correct torque specs for your specific engine.

Conclusion

The rocker arm torque spec for LS engines is pretty straightforward because it’s 22 lb-ft on all generations, versions, displacements, induction types, etc. Also, the tightening sequence is same too. That tightening sequence is to first position the number one cylinder to the top dead center of the compression stroke. Then, tighten the exhaust rockers on cylinders 1, 2, 7, and 8, plus the intake rockers on cylinders 1, 3, 4, and 5. After that, rotate the crankshaft 360 degrees and tighten the remaining rockers.