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TrailerParkBoy |
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#1
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Newbie ![]() Group: Members Posts: 8 Joined: 7-February 23 From: PNW Member No.: 27,145 Region Association: Pacific Northwest ![]() |
Intake seat let go. Ended up resting at angle to valve (odd location, usually they sit flat if loose?) which ended up taking a chunk from top of piston and scuffing cam lobe from pressure created. Much work ahead of us this weekend :-(
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gnomefabtech |
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#2
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Member ![]() ![]() Group: Members Posts: 147 Joined: 27-December 22 From: Los Angeles Member No.: 27,063 Region Association: None ![]() |
Looks to me like that valve seat did a dance in there and pitted the piston. I'm guessing that pieces of the head chipped off and also added to the pock mark party. I'm guessing the big dent was caused by the valve being held open and the piston hitting it.
Dropped valve seats are often caused by poorly executed valve jobs where the shop didn't take into account the expanding nature of an air cooled head and didn't fit the seat with enough interference. Or there was a crack or some other event that kicked the seat out of there. If the other cylinders all look good maybe just replace that piston and head. Very unlikely that the rod bearing is damaged unless you can see that the rod got bent. Once you reassemble, check if that piston sits low at TDC because that could mean a bent rod. I'm surprised the cam got damaged without bending the pushrod or bending other valvetrain parts. Check that too! |
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