4age broken cranshaft

[Liquidhandwash]

I everyone, just wanted to ask how common is it for a 4age to break a crankshaft?
I was lucky enough to find a small port 7 rib engine, in a barn, covered in bird shit... mostly complete, missing the flywheel and exhaust manifold, broken distributor.
I turned it over by hand and it made this weird clunk so I pulled the pants off it and found the crankshaft broken on the number 2 big end. It has 42 mm big ends, with oil squirter, so it the gen 3 16 valve.
The rest of the engine looks in very good condition so far, the broken crank was a surprise.
I'm thinking I might drop the head on a low mileage 4afe bottom end, while I look for a crank, flywheel and a rod, so I can continue with my project, kind of dummy motor that runs.
any thoughts about valves hitting pistons or crap compression ratio?

[trdee]

shouldn't just break no. it is likely to have met misfortune of some kind along the way..

[Liquidhandwash]

Thanks, I don't know the history of the engine it was in the barn when the guy bought the farm 10 years ago, It looks like it may have been replaced with another engine as there are a few things that were finger tight, injectors, distributor, so I may have had a huge turbo on it, or a bad tune who knows

[Liquidhandwash]

As I said it was a great barn find ..

[Ceasar]

Haha love the chicken feathers on it, good for barn find approval! Cranks can break due to a casting or forging flaw but this is very rare, or maybe a pre-detonation?