Nissan L24 / L28

Nissan's straight-six — the L24 and L28 — in the Datsun 240Z and 280Z, the Maxima and the Skyline.

It is the engine that made Datsun's reputation outside Japan, and it is a simple one: iron block, single overhead camshaft driven by a chain, and carburettors on the early cars.

The chain and its guides are the item that decides an engine. The plastic guides break down with age, and the tell is a rattle on start-up plus a timing mark that has wandered. Timing read from a stretched chain is timing read wrongly, which sends a fuelling diagnosis in the wrong direction.

On the carburetted cars the twin SUs are most of the fault list, and on the injected L28E the early analogue system has little to read — so diagnosis is compression, vacuum and fuel pressure measured rather than inferred.

These are heavily modified and frequently rebuilt, and a stamped code may no longer describe what is inside. The RB family that followed has its own page here.