C head bolt torque

Russ from MN · Apr 28, 2009

I am going to do some work on my rocker shaft and adjust the valves and my book doesn't have head bolt torque, does anyone know offhand, they look like 9/16 fine thread? Some parts on the rocker shaft have worn enough that the rockers don't line up with the valves, one as much as .050, I plan on adding some shim washers to the appropriate places to get them closer to being centered, should work? Thanks in advance!

MN Scott · Apr 28, 2009

80 ft lbs. Take them up in three steps.

NawlensGator · Apr 29, 2009

I replaced the rocker shaft on my C123 (140) after the head bolts were tightened, so I assume you are just going to check/retighten yours. Use the correct sequence. My manual says 80-90 ft-lbs. I went to 83. I haven't used washers as spacers but can't see why that wouldn't work. How did they get out od alignment?

ScottyHOMeY · Apr 29, 2009

Question. Is the head off and you're looking for torque for tightening the head back down? If that's the case, 80 ft-lbs is good. As MN Scott said, take it down in stages, like 45, then 70, then 80. And it's always a good idea to then warm the motor up well, then retorque.

I ask because most manuals have that torque spec. Some say 65, others say 80, which leaves me wondering, from the work you're describing if the head isn't still on and you're looking for the torque for the two smaller studs at the rocker supports. Those are 3/8" NF and the books I have dont' give a torque for them. SAE spec for a lubricated thread of that size is 25 ft-lbs.

Russ from MN · Apr 29, 2009

There seems to have been some wear in its 61 years, not a lot, but one valve stem is worn a little odd.

C head bolt torque

Russ from MN

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MN Scott

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NawlensGator

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ScottyHOMeY

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Russ from MN

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