[cdan34]

Randy, I likewise had a tapping noise in a 276 ci flathead a few years ago. When I first installed the engine I didn't hear the noise, than after a few thousand miles I started hearing this tapping. Off with manifold and readjust valves. The noise was still there and was becoming more noticeable. I knew something wasn't right so I located the cylinder, it was #6, head off, couldn't see a problem. So jack the '34 up and pull the pan, rods, pistons, bearings out. Everything mics OK, I look more closely at the #6 piston and there was too much clearance in the top ring. Everytime the piston reversed direction it would click. I don't think it was a machining error but the ring actually wore on the section that went in the groove. The groove in the piston was over, maybe .002. If you were to look at the ring cross section it was worn like a T the part that was in the groove was .075 thick and the very thin side that was between the piston and the cylinder wall was .093. They were 50s, 60s racing pistons never used with Grant rings. After cleaning engine up, in with new Ross pistons with thinner rings, problem solved. I've talked with other people and nobodies heard of this problem. How about anyone here ?

Chuck