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I was doing a topend rebuild on my 73 351C 4V. I had all the symptoms of a stuck Valve so off I went. I sent my Heads off to the machine shop for a complete overhaul and was replacing my lifters when I noticed the lifter furthest forward on NO.1 was not moving. When I removed it there was a small hole in the bottom. The corresponding lobe on the cam was worn to nothing. No other damage is apparent. I am going to replace the cam but I am concerned as to what could have caused this problem. The car was running smoothly and my oil pressure seemed normal even after the compression dropped in No.1
Any help would be appreciated.
 

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No replies? I hate to see a technical post disappear like that.

Possibilities I can think of:
Maybe the valve had been adjusted too tight? Or the spring was too stiff? Valvetrain geometry off? Oiling problem?

Any or all of the above can cause the lifter to not rotate on the cam lobe and grind itself down. A friend of mine used springs too stiff and ground down a bunch of lifters. If the head was tapped incorrectly for screw in studs some time in the past, it could cause what you describe. lay a straight edge along the rocker studs to see if they're all in line to rule that out. Talk to the machinist and see if he thinks it's the head, since he just worked on it. He may have better suggestions, too. And it might be a good idea to drop the pan and see how much metal is in it.

Robert
 
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