Purpose of blockPurpose of block Provides Strength with relatively simple Provides Strength with relatively simple

design.design. Supports and aligns internal parts.Supports and aligns internal parts.

LocationLocation EngineroomEngineroom

Main PropulsionMain Propulsion Ship’s Service Diesel Generator (SSDG)Ship’s Service Diesel Generator (SSDG)

Emergency Diesel/Auxiliary Machinery RoomEmergency Diesel/Auxiliary Machinery Room Emergency generatorEmergency generator Fire PumpsFire Pumps

Cylinder Block or Frame

En-Bloc or Cast: the block is cast in En-Bloc or Cast: the block is cast in one piece of aluminum or cast iron and one piece of aluminum or cast iron and is used in medium speed applications.is used in medium speed applications. Used mainly on small applications such as Used mainly on small applications such as

boats, emergency generators and pumps.boats, emergency generators and pumps. Usually no longer than 6 in line cylinders, Usually no longer than 6 in line cylinders,

or 8 V cylindersor 8 V cylinders Some applications have 2 or more blocks Some applications have 2 or more blocks

bolted togetherbolted together All contain internal oil passages to All contain internal oil passages to

distribute oil from the pump to the moving distribute oil from the pump to the moving parts inside the engine.parts inside the engine.

Types

Steel plates are cut and welded Steel plates are cut and welded vertically and horizontally to construct vertically and horizontally to construct the frame. the frame. A jig holds and aligns the pieces while they A jig holds and aligns the pieces while they

are welded.are welded. Some engines contain oil and water Some engines contain oil and water

passages welded into the frame work, while passages welded into the frame work, while others have removable pipes or tubing.others have removable pipes or tubing.

Found on larger engines such as Alco, Found on larger engines such as Alco, Fairbanks-Morse, General Motors, and Colt-Fairbanks-Morse, General Motors, and Colt-Pielstick.Pielstick.

Welded Steel:

Cylinder LinersCylinder Liners

Purpose- Allow individual cylinder bores to be Purpose- Allow individual cylinder bores to be replaced when they become worn.replaced when they become worn.

Cylinder liners are inserts placed inside the Cylinder liners are inserts placed inside the cylindrical holes in the block.cylindrical holes in the block.

Types:Dry Type

Liner is a thin wall shell of cast iron or Liner is a thin wall shell of cast iron or steel and can either be pressed in or loose steel and can either be pressed in or loose fitted to the block.fitted to the block.

Cooling water does not contact any part of Cooling water does not contact any part of the liner.the liner.

Heat is transferred from the liner to the Heat is transferred from the liner to the block and from the block to the water block and from the block to the water passages in the block.passages in the block.

Water is in contact Water is in contact with some part of with some part of the liner.the liner.

The wall of the liner The wall of the liner is thicker than the is thicker than the dry type, and water dry type, and water circulating in the circulating in the block comes in block comes in contact with the contact with the outside surfaces of outside surfaces of the liner.the liner.

Wet Type Water Jacketed- Cooling water is circulated in the liner only. Water passages are cast into the liner, coolant does not contact the block.

Wet type 2 stroke liners have Wet type 2 stroke liners have provisions for additional rubber provisions for additional rubber seals on the belt surrounding seals on the belt surrounding the ports.the ports.

2 cycle liners have scavenging 2 cycle liners have scavenging ports, exhaust ports or both.ports, exhaust ports or both.

CrankcaseCrankcase Purpose:Purpose:

Serves as a housing Serves as a housing for the crankshaft.for the crankshaft.

Incorporates the Incorporates the bolting flanges, bolting flanges, lower main bearing lower main bearing saddles and an oil saddles and an oil trough.trough.

On some engines the On some engines the crankcase is an integral crankcase is an integral part of the cylinder part of the cylinder block.block.

On others, the On others, the crankcase is a separate crankcase is a separate part and is bolted to part and is bolted to the lower part of the the lower part of the block or frame.block or frame.

BaseBase- Combination - Combination bedplate and oil panbedplate and oil pan Requires the block to Requires the block to

complete the frame for complete the frame for the main bearings.the main bearings.

Location:

SumpSump Purpose: Collects Purpose: Collects

and holds the and holds the engine lube oil.engine lube oil.

Location: Sumps Location: Sumps are usually are usually attached directly to attached directly to the bottom of the the bottom of the engine.engine.

Oil is contained Oil is contained within the engine, within the engine, no outside storage no outside storage is used.is used.

Usually found on Usually found on small diesel small diesel enginesengines

Wet Type Sump

Crankcase acts as a Crankcase acts as a drain trough.drain trough.

All oil storage is in All oil storage is in the external tanks.the external tanks.

Dry sump design is Dry sump design is common in larger common in larger engine sizes.engine sizes.

Dry Type Sump

Purpose- Adds Purpose- Adds rigidity to the rigidity to the block.block. Provides a Provides a

mounting surface mounting surface for parts such as for parts such as gears, pumps, gears, pumps, blowers, and blowers, and generators.generators.

Location- Attached Location- Attached to each end of the to each end of the cylinder block.cylinder block.

End Plates Access Covers Purpose – Allows for Purpose – Allows for

inspection of :inspection of : Cylinder LinersCylinder Liners Main BearingsMain Bearings Connecting Rod Connecting Rod

BearingsBearings Injector Control ShaftsInjector Control Shafts Various Other Internal Various Other Internal

PartsParts Valve AssembliesValve Assemblies Intake/Exhaust Intake/Exhaust

ManifoldManifold

Location – Engine Location – Engine BlockBlock

Usually secured with a hand wheel or nut operated Usually secured with a hand wheel or nut operated clamps and are fitted with gaskets to keep dirt and clamps and are fitted with gaskets to keep dirt and foreign material out of the engine.foreign material out of the engine.

On some engines, the covers are constructed to serve On some engines, the covers are constructed to serve as safety devices.as safety devices. The covers are equipped with a spring loaded The covers are equipped with a spring loaded

pressure plate which keeps the plate sealed under pressure plate which keeps the plate sealed under normal operating conditions.normal operating conditions.

In the event of a crankcase explosion or extreme In the event of a crankcase explosion or extreme pressure in the crankcase, the pressure overcomes pressure in the crankcase, the pressure overcomes the spring tension, and the plate acts as a safety the spring tension, and the plate acts as a safety vent.vent.

Also referred to as inspection covers or hand hole covers.

Access Covers continued

Rocker/Valve covers allow Rocker/Valve covers allow access to valve access to valve mechanisms and prevents mechanisms and prevents dirt from entering the dirt from entering the engine.engine.

Greater variation in Greater variation in design than any other design than any other single element of an single element of an engine.engine. Purpose Purpose

– – Forms a seal for the Forms a seal for the

combustion space. combustion space.

Constructed of cast alloy Constructed of cast alloy

iron, or aluminum. Each iron, or aluminum. Each

cylinder may have cylinder may have

individual heads or individual heads or

cylinders may share heads.cylinders may share heads.

Location Location

– – bolted to the top of the bolted to the top of the

cylinder block.cylinder block.

Cylinder Head

Open Combustion Open Combustion ChamberChamber – Used on – Used on large, slow speed large, slow speed engines.engines.

Types

Pre-Combustion Chamber – A small cavity is built into the head. Cavity is used to provide a small combustion area causing turbulence which flows into the main combustion space to aid in the air/fuel mixture and combustion.

Heads may contain intake Heads may contain intake and/or exhaust valves, and/or exhaust valves, rocker arm assemblies, rocker arm assemblies, fuel injection valves and fuel injection valves and air starting valves.air starting valves.

Construction

Cooling water passages are provided in the head to remove heat from the head, valves, and injector. Coolant is introduced from the block or liner into cored passages of the head.

Cylinder heads may also be fitted with air starting valves, indicator cocks, and safety valves.

Purpose Purpose To secure the engine to the ship. Can also be used to To secure the engine to the ship. Can also be used to

maintain alignment between the driven unit and the maintain alignment between the driven unit and the engineengine

LocationLocation Beneath the bedplate or engine frame.Beneath the bedplate or engine frame.

TypesTypes Solid – Bolted directly to the frameSolid – Bolted directly to the frame

Engine Mountings

Shock AbsorbersUsed to suppress major vibrations that may occur. These vibrations are external from the engine such as bombs, detonation of shells, etc.

Vibration Isolators Used to suppress minor vibrations caused by the engine. These are high frequency, small amplitude engine vibrations from moving parts.