Hi guys, a had quite a lot o fuel in the oil of ma 600f, a drained it blew out plugs an let it sit over night to let all fuel evaporate, when a put I back together there is severe knocking, am assuming it's the big end, can anyone shed some light on it, is it feasible t change the shells without a crankshaft regrind?

 

I have seen cases where the shells were replaced without any extra attention to the crankshaft.
However if you expect that the crankshaft shells burned because of a lack of lubricant I would assume you would have a lot of more problems.
Basically, yes you can change the shells without grinding the crankshaft if the crankshaft is not all scratched up or lost its hardness due to heat.

 

That's perfect, cheers, it was running great before this, once a finished this morning an started her up I got the knock straight away so shut er down, hopefully crank should be saved, can this be done with engine still in the frame

 

personally I think it might be very possible. However do you want to?
Because if you can turn the engine block upside down you can easily check all other things that might hve been damaged, and above all you can clean the engine much better.
Displaced shells should be mechanical impossible, so displaced shell point to much more problems.
Very critically checking the engine is very hard when it is still in the frame.
Point is this: You increase your chances of a succesfull fix tremendously when getting the engine out even though it is a lot of work.