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Rocker Arms


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  • 2 weeks later...
22 ft lbs, rotate the motor 180* then 22 ft lbs again

 

180 degrees? That is an odd number for a 4 stroke. I would have expected 360 degrees to get the engine on the side of the 4 strokes, unless you were to repeat the 180 degrees once.

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According to the GM manual it is 360 degrees. And, there is a specific order on what cylinder and what rocker to torque. I don't have it in front of me but I can post it later if you'd like.

I'd be interested to see that.

 

the specs I quoted are from a 2002 LS1 which would apply to all LS1 based motors. I've had my hands in quite a few cam swaps and these specs have held everything together for several motors spinning in excess of 6,000 rpms over quite a few miles.

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According to the GM manual it is 360 degrees. And, there is a specific order on what cylinder and what rocker to torque. I don't have it in front of me but I can post it later if you'd like.

+1 on 360 on crank

 

22 ft. lbs

 

6. Rotate the crankshaft until the number one piston is at top dead center (TDC) of the compression stroke.In this position, cylinder number one rocker arms will be off lobe lift, and the crankshaft sprocket key will be at the 1:30 position.The engine firing order is 1, 8, 7, 2, 6, 5, 4, 3.Cylinders 1, 3, 5 and 7 are the left bank.Cylinder 2, 4, 6 and 8 are the right bank. Notice: Refer to Fastener Notice in Service Precautions.

7. With the engine in the number one firing position, tighten the following valve rocker arm bolts:

 

o Tighten the cylinders 1, 2, 7 and 8 exhaust valve rocker arm bolts to 30 Nm (22 ft. lbs.) .

o Tighten the cylinders 1, 3, 4 and 5 intake valve rocker arm bolts to 30 Nm (22 ft. lbs.) .

 

8. Rotate the crankshaft 360 degrees.

9. Tighten the following valve rocker arm bolts:

 

o Tighten the cylinders 3, 4, 5 and 6 exhaust valve rocker arm bolts to 30 Nm (22 ft. lbs.) .

o Tighten the cylinders 2, 6, 7 and 8 intake valve rocker arm bolts to 30 Nm (22 ft. lbs.) .

 

10. Install the valve rocker arm cover.

Edited by txab
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  • 4 years later...
  • 4 years later...

I know this is an old post but I am replacing head gaskets on my 2000 GMC Sierra 5.3. When we get to the point of torquing down the rocker arms, what is the proper procedure? One guy says 180 and then another one says 360. If you rotate the crank 360 degrees aren't you right back in the same position as before? Number one piston is right back at TDC. Also does the cam turn at half the speed or twice the speed as the crank? 

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