Bottom end knocking?

[herb]

My mates combo developed a bottom end knocking noise we stripped the bottom end down to discover the shell on piston 1's conrod had disintegrated so we replaced the shell's. All good for 2 days then the same thing happened So with our limited mechanical experience we are thinking the crank needs replacing. So I'm asking on here to see if this is what people with more experience of engine's would do or would you just go down the route of engine swap ?
Any help on this would be appreciated!

 

[old-git]

Without seeing the engine and the damage, the same thing happening within a couple of days indicates that something is out of line, probably the crank. If you can source a decent engine this would probably be both easier and cheaper than a rebuild.

 

[herb]

Cheers for the reply Steve!
But 30 minutes before your reply i get a text of my mate telling me the crank will be of tomorrow being reground/balanced and new offset shell's have been ordered all in at mates rates of £50 so I hope this works as a easier fix!
If not we do have a backup we picked up a non runner today with fueling or immobiliser issues bought it at just over scrap value

 

[old-git]

Probably teaching you how to suck eggs, but check that the crank turns freely before attaching rods

 

[herb]

Probably teaching you how to suck eggs, but check that the crank turns freely before attaching rods

Not at all Steve!
As I say we are novices atythis sort of thing!
So useful advice is always appreciated!
And will do