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440 knocking

Did you collect all of the spark plug pieces? Did you take apart the cylinder head and inspect the valves and check for debris?

Usually, when something like this happens, the debris will end up in other cylinders as well. Pull both cylinder heads.
 
Did you collect all of the spark plug pieces? Did you take apart the cylinder head and inspect the valves and check for debris?

Usually, when something like this happens, the debris will end up in other cylinders as well. Pull both cylinder heads.
how is it possible for debris able to jump from one cylinder to another !!!
 
A slightly bent rod can make you chase your tail too.. I’ve heard stories of locos bending the rods if they weren’t blown down before starting.. And they won’t bend much just a little and then comes the knock.. Check the rod good, look at the bearings good .. Bore taper messing with the piston causing it to rock? Idk if it’s possible but I think it could be. I’m just spit balling and trying to help..!
 
how is it possible for debris able to jump from one cylinder to another !!!

The intake valve opens before the piston get to TDC. It might not have happened in your case, but it is not uncommon for debris from one cylinder to get into one or more other cylinders. One piece of debris can cause damage in a few cylinders.
 
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Had a piston come apart at the race track once. Debris got into EVERY other cylinder!!
 
Just me but like posted already I would really check the rod for any bend, Both ends still round ?
Plastic gauge the crank end ?
I bet when you pull it down this time you will find some witness Mark's on the new parts.
 
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