Core plug seat corrosion

[Reckless Rat]

Being a time served bodger, I would clean out the remnants of the old core plug, clean up the top surface of the casting and araldite a metal disc to the cleaned up face. The cooling system isn't pressurised so it should be fine thereafter.

This is assuming that it's a "cooking" engine and not something likely to be presented to the National Association of Rivet Counters.

Yours sincerely
Scrooge Mc Duck.