A blown engine can either be a nightmare of epic proportions or a fairly simple weekend project–the difference comes down to knowledge and preparation. Think of your engine disassembly as an autopsy and don’t take anything at face value. Stay vigilant for cascading, cause-and-effect failures and expect to spend twice what you think you will. A “blown” engine can be the result of anything, from a simple head gasket failure to a crankshaft snapped in two, so don’t buy any new parts until you know what’s going on with the engine.
Diagnose the engine during teardown, taking it slowly and staying organized. Remove the valve covers and intake manifold, checking for debris in the oil and broken valve springs/valve train components. Remove the cylinder heads and examine the piston tops and combustion chamber roofs for signs of oil leakage, water leakage and melted components.