Reply To: ’56 Lark rebuild: Unusual noise at piston/rod/crank preassembly

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January 3, 2026 at 2:00 pm #302948
Gary H.
Participant

    US Member

    I looks like your crankshaft jumps or skips in the video when you hear the noise. The pistons don’t seem to jump in the video from what I can see.  Is it possible to determine if the noise happens on a particular piston stroke when it is all the way up or all the way down? Is the noise coming from the same piston or coming from both pistons alternately? Just trying to help diagnose before you have to pull engine apart again. I don’t know particulars about your engine but could it be a bad connecting rod bearing?  I am sure someone may be able to help diagnose the noise.