Engine Clanking Noise, Just looking for thoughts Options

[Mblizzard]

In the process of installing my dual carbs I spent a lot of time listening to the engine. I notice what I would classify as an internal clanking sound on the number 3 cylinder. Which of course varied with engine speed but is present to some degree at idle. I recently reset the valves so I am fairly sure it is not that as it has none of the tapping sound I associate with valve clearance issues. It is much more of a clunk. Engine runs well and has good compression so I am thinking it is a problem that is much deeper.

This is a 1.8 with a big bore (96mm x 66mm) and a mild cam. I am thinking piston wrist pin? I will go back and check the valves before doing anything but I thought I would see if someone might have suggestions on other possibilities

Any thoughts on other sources?

[rhcb914]

Check to see if you tightened down your valve adjuster jam nut. I've done that before and it makes 1 hell of a racket when they back out. Also I have run across improperly hardened adjuster screws. I would adjust the valves and days later start hearing a light knocking noise that would progressively get worse.

If it's a wrist pin bushing you can tell by pulling the plug wire off and rev the engine. If the sound goes away it's likely the bushing.