[NeighborsComplaint]

It's been a great run Mikey. Your enthusiasm and claims of owning a 1 of none 1967 428 HO tripower mystery motor have provided invaluable entertainment. However, it's time to get in touch with that reality we as kids thought served no purpose than to spoil our fun. Time to take the motor to a professional and flush all your theories down the toilet.

It's time to determine if the rods are installed backwards or just the pistons. Unless you know what you are looking for or have rod to reference, you won't know the difference. Both sides of the rods have a chamfer. One side is "eased" to prevent stress cracking form a sharp edge, The other side has a much larger chamfer intended to be installed facing counterweights and allowing the rod to ride over the fillet all the way to the counterweight.

When you install the rods backwards, there is no chamfer to clear the fillet on the crankshaft and secondary thrust wedges the rod bearing into the crank fillet causing the cap to displace and create a sharp edge contact point between the rods on the same journal and ultimately seize the rod to the crankshaft.

I have every confidence your "ghost noise" is one rod face bouncing over the edge of the displaced cap at low RPM. At higher RPM, it becomes masked by other mechanical noises within the engine and just becomes an odd whirring or scuffing sound that seems to follow the engine RPM but seems oddly out of synch with it.

The noise would eventually go away once the engine goes silent after you spin a rod bearing or two and seize the crankshaft.