Freshly rebuilt 2L spider motor, was running good about 10 hours, getting the Webers and valve clearances adjusted. Fired her up yesterday and while warming up I heard a few clunks that did not sound at all normal. Checked valve train, appears ok, 5 psi compression on cyl. #3. 160 on the rest. #3 piston is moving up and down. Engine builder is old, maybe has lost touch (self)
It appears something catastrophic happened, any ideas?
Pulled the cyl head off, a small metallic something found it's way into the combustion chamber. The top of the piston, underside of the head and valves are peppered with small dents. Generally I am very careful when the spark plugs are removed or when the carbs are off to make sure this does not occur. Hopefully the bottom end is ok.
Heading off to my local machine shop tomorrow to replace the damaged valves.