Rocker arm install question
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2nd Gear
Joined: Feb 2023
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Rocker arm install question
I'm changing the head on the passenger side of a 2011 f350 with the engine still in cab. When looking at the rocker arm install procedure the manual says
"1. Position the crankshaft with the cylinder number No. 1 approximately 155 degrees after Top Dead Center (TDC) by observing the crankshaft pulley dowel pin and clocking it to the 3:40 position (as viewed from the front of the engine).
2. Determine which cylinder is actually in the firing position by observing the push rods for the No. 1 exhaust push rods should be raised .0394” (1.00 MM) and No. 4 exhaust push rods should be raised .0591” (1.50 MM). If the push rods are not in the correct position, rotate the engine one revolution clockwise (360 degrees)."
What is the purpose of positioning the cylinder 155 degrees after TDC?
Can the rocker arms be installed without doing this step?
If not, can someone reference which push rods are #1 exhaust and #4 exhaust.
"1. Position the crankshaft with the cylinder number No. 1 approximately 155 degrees after Top Dead Center (TDC) by observing the crankshaft pulley dowel pin and clocking it to the 3:40 position (as viewed from the front of the engine).
2. Determine which cylinder is actually in the firing position by observing the push rods for the No. 1 exhaust push rods should be raised .0394” (1.00 MM) and No. 4 exhaust push rods should be raised .0591” (1.50 MM). If the push rods are not in the correct position, rotate the engine one revolution clockwise (360 degrees)."
What is the purpose of positioning the cylinder 155 degrees after TDC?
Can the rocker arms be installed without doing this step?
If not, can someone reference which push rods are #1 exhaust and #4 exhaust.
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2nd Gear
Joined: Feb 2023
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Yeah the push rod question was kinda dumb, the # 1 and 4 exhaust push rods would be on these valves.
Still, why can’t I just bolt back on the rockers? What’s the purpose of clocking if the engine hasn’t been turned over since removing the rocker arms. Shouldn’t everything still be in the same position?
Super Moderator
Joined: Aug 2008
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From: Frederick, MD
back in the old days, I would just put it together if nothing changed. Wonder if the concern is a timing issue. Again if nothing changed then timing of the motor should not be an issue.
Maybe the book thinks that the head or valves were replaced with new?
Maybe the book thinks that the head or valves were replaced with new?
Hotshot
Joined: Jul 2013
Posts: 14,266
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I did the rockers on a 6.4
same book spec about positioning the crank before torquing.
couldn’t figure out how to do the crank repositioning.
so against common sense…I installed the rockers..did a minimal torque on all the rockers…quickly spun the motor…torqued the rockers some more…quickly spun the motor again….and did a final torque.
nothing broke on my engine…no guaranty this approach will work for anyone else.
same book spec about positioning the crank before torquing.
couldn’t figure out how to do the crank repositioning.
so against common sense…I installed the rockers..did a minimal torque on all the rockers…quickly spun the motor…torqued the rockers some more…quickly spun the motor again….and did a final torque.
nothing broke on my engine…no guaranty this approach will work for anyone else.
Cross-Country
Joined: Jan 2022
Posts: 56
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Honestly I gave up on trying to figure that out out. Ended up doing what I would on other engines. Rotating each cylinder to relive the springs then torqued the rockers down to spec. As when I did this step it didn't make any sense, Since one of two of the cylinders valve springs were putting slight pressure on the rockers. EDIT: Granted this may have also because I was installing a aftermarket cam now that I'm thinking of it.
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