For a diesel engine to start effectively, what must it achieve?

For a diesel engine to start effectively, it is crucial that the engine turns over fast enough to create sufficient heat for combustion. Diesel engines rely on high compression ratios to ignite the fuel-air mixture; this process generates significant heat. If the engine does not rotate quickly enough, the compression may not produce the necessary temperature to ignite the fuel, preventing the engine from starting.

Sufficient cranking speed helps ensure that the engine can build up the required pressure and temperature before fuel is injected. It’s important to note that while other conditions, such as oil pressure and fuel injection, are also significant in engine operation, the primary requirement for initiating the combustion process in a diesel engine is having adequate rotational speed to generate the necessary heat for ignition. This is why ensuring the engine "turns over fast enough to create sufficient heat" is crucial for effective starting.