How to cold start a marine diesel engine

It can be a difficult procedure to start off a marine diesel engine from cold with unique techniques demanded for various engines. Callum Smedley deliver us his guide

Starting a diesel motor from chilly can be a tough company. Several direct-injection engines use further gasoline for cold starting off. On some, these as compact Yanmars, this excess fuel is equipped automatically, and the operator want do practically nothing apart from established the ‘throttle’ the right way. On other individuals, even so, specific actions have to be taken prior to setting up from chilly. For instance, on aged Volvos and Listers, there is a cold-commence button at the again of the motor that need to be pressed down for each cold start out try. This action permits the gas manage rack to run to a ‘cold-start’ posture by removing a block on the fuel rack, a method also recognized as ‘over fuel’. On the Petter Mini 6 and Mini Twin, a wire loop will be discovered on the front of the motor. This is pushed down and released following the ‘throttle’ has been set in advance of beginning.

Compression Ratio

The engine’s compression ratio can be enhanced for chilly starting up on some engines by the addition of lubricating oil to the cylinder earlier mentioned the piston. This chilly, thick oil receives close to the piston rings and valves, serving to to seal them better. Significantly less air is lost during compression, which indicates the final force will be bigger and, of study course, hotter. This is finished on the Petter Mini 6 and the Mini Twin, and some Sabb engines.

An electric heater equipped inside of an air manifold


Engines which have oblique injection are fitted with pre-heating as an help to chilly starting up, and some direct engines may well be fitted with a kind of pre-heating as an solution for use in very low-temperature circumstances.

Glow plugs

Electric pre-heater plugs (glow plugs) are fitted forever in the combustion chamber and run prior to start off from the engine’s electrical technique. The heater pre-heats the total combustion chamber. Its idea, which extends into the combustion chamber, is nonetheless warm when the gas is injected, aiding ignition. For that reason a three-cylinder motor has a few glow plugs, just one for just about every cylinder.

On autos, an orange light-weight on the instrument panel is illuminated when pre-heat is selected and goes out when the demanded temperature has been attained, indicating that the starter motor can now be engaged. On most maritime engines, nevertheless, this sign is not supplied, so the operator demands to be mindful of how prolonged the pre-heat should really be applied for.

A diesel oil burner and igniter heat the air consumption

Electrical coils

An electrical coil, mounted in the air consumption manifold, is supplied with electric powered electricity for the duration of chilly starting off to pre-heat the air as it passes into the cylinder.

Ignition burner

A gasoline reservoir materials a burner in the air intake manifold. This burner is ignited for the duration of a chilly begin to pre-heat the air and was typical on Perkins 4-107, 4-108 and 4-109 engines. It really should be famous that smoke can come out of the air consumption filter through heating.

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