I have started on the drivers side today replacing valve seals on my truck. My question is when I reinstall the rockers does it matter the position of the lifters? Do I torque and go or do I have to find TDC and tighten the corresponding rocker arms? Then turn it over and do it again. I was assuming the hydraulic lifters would allow you to torque and go. Or can I tighten them while it's running? Honest questions. This is on my 78 460 btw. Thanks,Marco

 

I always tighten them down when the respective lifter is on the low side of the cam lobe, this ensures I'm not fighting against the valve spring and that all the torque I put on the bolt goes for tightening it to the head, if that makes any sense... So yes, I turn the engine over by hand as I go around the valves, and I'm not necessarily looking for the TDC for each cylinder either, just as long as the valve I'm working on is closed it's good. Being at TDC for each cylinder does make things somewhat easier to figure out tho.

 

Thanks for the fast reply LCAM, I just want to make sure I don't overtighten or break anything. I get what your saying. I was looking at them and thought just tightening them wouldn't be consistent. They are completely loose at the moment.

 

I don't think you'll damage or break anything if you tighten them down as they sit, but you're right that the tension on the bolts may not be consistent. Also when you tighten them down do it by hand first while making sure the tip of the rocker remains centered over the valve stem, I've noticed that sometimes the rockers will try to rotate somewhat if you don't hold them in place and the valve stem ends up riding on the corner of the rocker tip, which I can't imagine is good for the rocker or the pushrod.

 

NON-ADJUSTABLE ROCKER ARMS




Gasoline V8 Engines<O

• Crank the engine until the No. 1 cylinder is at TDC of the compression stroke and the timing pointer is aligned with the mark on the crankshaft damper.

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• Scribe a mark on the damper at this point.

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• Scribe two additional marks on the damper (see illustration).

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• With the timing pointer aligned with mark 1 on the damper, tighten the following valves on the specified torque:

255, 302, 360, 390 and 460: Nos. 1, 7 and 8 Intake; Nos. 1, 5 and 4 Exhaust <O
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351, 400: Nos. 1, 4 and 8 Intake; Nos. 1,3 and 7 Exhaust
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• Rotate the crankshaft 180 degrees to point 2 and tighten the following valves:
• 255, 302, 360, 390 and 460: Nos. 5 and 4 Intake; Nos. 2 and 6 Exhaust <O

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351, 400: Nos. 3 and 7 Intake; Nos. 2 and 6 Exhaust
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• Rotate the crankshaft 270 degrees to point 3 and tighten the following valves:

255, 302, 360, 390 and 460: Nos. 2, 3 and 6 Intake; Nos. 7, 3 and 8 Exhaust <O
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351, 400: Nos. 2, 5 and 6 Intake; Nos. 4, 5 and 8 Exhaust
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• Rocker arm tightening specifications are:

Except 460: tighten the nut until it contacts the rocker shoulder, then torque to 18-20 ft.lb. <O
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460: tighten the nut until it contacts the rocker shoulder, then torque to 18-22 ft.lb.
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Thanks smokey, that's what I did. I found the 1978 shop manual and that's what the instructions were. I feel confident about it now.