Valve Stem wearing off center
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From: Bell Buckle, TN
St. Jude Donor '11
Valve Stem wearing off center
I noticed a ticking in one of our motors and pulled the rockers and noticed one of the valve stems is wearing on the outside edge. Would this be from a worn valve guide?
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From: Howell Michigan
St. Jude Donor '09-'10-'11
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From: Bell Buckle, TN
St. Jude Donor '11
Its an LS1. I pulled the head and am taking it to a head shop to have the valves inspected. Im pretty sure its the valve guide. The rocker appears to be ok. Car has 95k.
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From: Bell Buckle, TN
St. Jude Donor '11
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From: Houston Texas
I've seen this in older 350 small blocks when the pushrod guide gets too big. Changes the geoemetry of the pushrod/rocker/valve stem where the rocker doesn't push straight down anymore. Turns the rocker to one side slightly and causes the rocker and valve stem to wear more on one side.
Burning Brakes
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From: Ottawa Ontario, Canada
I've been wrong before though.
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From: Dyer, IN
As far as I can tell there are no pushrod guides in LS motors... I'm tearing my LS6 down right now and as I see it nothing but the lifter and rocker touch the pushrod. The rockers are kept pointing in the right direction by the "cradle" they sit in, part of a long shaft that supports all the rockers in the head.
I've been wrong before though.
I've been wrong before though.
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From: At the beach in little Rhody
Did the rocker geometry get reset for the higher lift? If not, the higher lift may have caused the sweep pattern of the rocker to extend to the outer edge of the valve stem. I have seen cases where the rocker actually goes over the outer edge of the valve stem. Then of course higher force valve springs simply hasten any issues.
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From: Bell Buckle, TN
St. Jude Donor '11
Did the rocker geometry get reset for the higher lift? If not, the higher lift may have caused the sweep pattern of the rocker to extend to the outer edge of the valve stem. I have seen cases where the rocker actually goes over the outer edge of the valve stem. Then of course higher force valve springs simply hasten any issues.
After inspection of the head it appears that spring was sitting slightly lower than the rest of them. We are replacing the valve stem and setting all the springs to the proper height. The springs were tested and were fine and the valve guides were not worn.
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From: Howell Michigan
St. Jude Donor '09-'10-'11
We just got this motor in so im unsure of what was done in the past.
After inspection of the head it appears that spring was sitting slightly lower than the rest of them. We are replacing the valve stem and setting all the springs to the proper height. The springs were tested and were fine and the valve guides were not worn.
After inspection of the head it appears that spring was sitting slightly lower than the rest of them. We are replacing the valve stem and setting all the springs to the proper height. The springs were tested and were fine and the valve guides were not worn.
Burning Brakes
Joined: Feb 2006
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From: Ottawa Ontario, Canada
12552203 is the part number on the cradle/shaft thingy that aligns the rockers. My #7 rocker appeared to be a bit skewed when I pulled the covers. When I reassemble the engine I will try switching it out with the one from the pass side head and see if the rocker straightens out. It appears it may have been bent when torquing the rocker arm down at the factory maybe??? Not sure how else it would get bent (if it is indeed bent).
