I gather you're in Pomgolia (the UK), like most of the members here.
Given how many cars rust out overnight there, I would think there would be perfectly good engines readily available,
It would probably easier just to bolt one of these in.........and when you do, fit a bloody low water alarm, if you had one of these you wouldn't have blown it up in the first place!
"Keep calm, relax, focus on the problem & PULL THE BLOODY TRIGGER"