Chevy 350 girding noise from main bearings?

[MrSony]

Hey all. A buddy of mine is building a mild SBC and right now all he has is the bottom end together. The crank turns over like BUTTER with Moly Black assembly grease but there is a faint audible grinding sound coming from what seems to be the main cap right before the rear one. Is this bad? The engine was never apart prior to him getting it, it was a high mileage engine, but ran well for many years. He decided to rebuild it. Stock crank, new bearings. And the caps are in the right place. Clearance checked out fine with plastigauge and minimal measuring tools. What could it be? The engine never was warped, dropped, or overheated. Would it just eventually "self clearance", or should this be addressed immediately? Thanks in advance.



*********Meant to say "GRINDING", not girding. Stupid spellcheck***********

 

[pontiacgp]

what does the bearing and crank look like at that jounal

 

[MrSony]

It looks mint. If you're talking about the bearing surfaces, they are still new and still have the coating on them. Not the rust proofing, the grey stuff that is ontop of the bare metal. They are sealed power bearings. I've seen engines run fine with much worse, my brother's SBC '74 silvarado case in point. Crank still rolls smooth as glass in there though.

 

[pontiacgp]

with that cap and bearing removed is the noise still there when the crank is rotated?

 

[MrSony]

No.

 

[MrSony]

Im thinking it's the cap, but they are in the right place. He made sure of that, and he's no fool. the crank is a bit worn though, it;s the original crank. Crank was still shiny and had no bad spots, was still in perfect balance.

 

[pencero]

A mediocre effort will usually achieve mediocre results; if you continue on w/ the engine like that will it still perform well: yes. Obviously if you start all over again and figure out what small thing it is you would have a engine that uses significantly less oil and last a longer time; the longer anything sits without being used it will warp over time especially if its not in climate controlled storage... but crossing denial river was never easy.