motor is knocking

[ministermi]

1980 spider was running great, went out to let it run, heard knocking. Dropped the pan romoved the connecting rod
bearing cap, all appears to be ok, no wear, no movement in rods. 1st does anyone have any idea what it could be, and
2nd is there a fiat mechanic in the central area of NJ?

[So Cal Mark]

I'd try to pinpoint where the noise is coming from. 2L motors can have interference between a con rod and the aux shaft. Or, something may have gotten into a cylinder