Cylinder Head
The individual cast-iron cylinder heads, one for each cylinder unit, are equipped with a centrally situated fuel injection valve, two inlet valves, two exhaust valves and one indicator cock. The head has a thick, bore-cooled flame plate for satisfactory control of mechanical and thermal loads and stress. The cylinder head is attached by means of 4nuts and 4 studs screwed into deep bosses in the engine frame top plate. The nuts are tightened by means of hydraulic tools.
Inlet and Exhaust Valves
The valve spindles are made of heat resistant material. Hard metal is welded on to the valve spindle seats. The valve spindles are fitted with valve rotators which turn the spindles a little each time the valves open. The cylinder head is equipped with replaceable seat rings for inlet and exhaust valves. The seating surfaces are hardened in order to minimize wear and prevent dent marks, on the inlet seat by induction hardening, on the exhaust seat by hard metal armouring.
Piston
The piston, which is oil-cooled and of the monobloc type made of nodular cast iron, is equipped with 3 compression rings and 1 scraper ring. By use of a combination of compression rings with different barrel-shaped profiles and chrome-plated running surface on all rings, the piston ring pack is optimized for maximum sealing effect and minimum wear rate. The piston has a cooling oil space close to the piston crown and the piston ring zone. The heat transport, and thus the cooling effect are based on the shaker effect arising during the piston movement. Oil from the engine's lubricating oil system is used as cooling oil. The piston is provided with a turned edge at the top due to the flame ring mounted in the cylinder liner.
Piston Pin
The piston pin is fully floating which means that it can turn freely in the pin bosses of the piston as well as in the connecting rod bush. The piston pin is tumed in place upwards in axial direction by two circlips (seeger rings).
Connecting Rod
The connecting rod is die-forged. The big-end has an inclined joint in order to facilitate the piston and connecting rod assembly to be withdrawn up through the cylinder liner. The joint faces on the connecting rod and the bearing cap are serrated to ensure precise location and to prevent relative movement of the parts. The big-end bearing is of the trimetal type, i.e. steel shells lined with tin-aluminium or lead-bronze coated with a running layer. Designed as plain type or rillentype. The bearing shells are of the precision type and are therefore to befitted without scraping or any other kind of adaption. The small-end bearing is of the trimetal type and is pressed into the connecting rod.
Cylinder Liner
The Cylinder liner is made of fine-grained, pearlite cast iron and is fitted in a bore in the engine frame. Replaceable cast iron sealing rings are fitted between the liner and the cylinder head and between the liner and the frame. The liner is clamped by the cylinder head and is guided by a bore at the bottom of the cooling water space of the engine frame. The liner can thus expand freely downwards, when heated during the running of the engine. Sealing for the cooling water is obtained by means of silicone rubber rings which are fitted in grooves machined in the liner. The cylinder liner is of the so caIIed "stepped cylinder” type, provided with flame ring inserted in the top of the liner.
Camshaft
The camshaft which controls the actuation of inlet valves, exhaust valves and fuel injection pumps is driven by a gear wheel on the crankshaft through an intermediate wheel, and rotated by a speed which is half of that of the crankshaft. The camshaft is located in a high level housing in the engine frame. The camshaft runs in replaceable, identical, steel-backed bronze bushings fitted into borings of the transverse girders in the housing. The camshaft is built-up of sections, one for each cylinder unit. Each section is equipped with fixed cams for operation of fuel injection pump, air inlet
valve and exhaust valve. The sections are assembled by bolting of the ample dimensioned and precision made flange connections, which also act as bearing journals. Except for the foremost and the aftmost ones: the sections are identical and therefore interchangeable. The foremost section is equipped with a clutch for driving the fuel oil feed pump (if mounted). The gear wheel for driving the camshaft as well as a gearwheel connection of governor are screwed on the aftmost section. The lubricating oil pipes for the gear wheels are equipped with nozzles which are adjusted to apply the oil at the points where the gear wheels are in mesh. The position of the holes is determined by direction of rotation of the engine.
Roller Guides
The fuel injection pumps and the rocker aims for inlet and exhaust valves are operated by the cams, on the camshaft through roller guides. The roller guides for fuel pump, inlet and exhaust valves are located in bores in a common housing for each cylinder, this housing is bolted to the engine frame. The roller runs on a bush fitted on a pin that is pressed into the roller guide and secured by means of a lock screw.
Operating Gear for Fuel Injection Pumps
The injection pumps which are mounted directly on the roller guide housing are activated via thrust pieces from the roller guide. The roller is pressed down on to the cam by a spring, which is fixed between the roller guide and the foot plate of the fuel injection pump.
Operating Gear for Inlet and Exhaust Valves 
The movement from the roller guides for inlet and exhaust is transmitted via the push rods the rocker arms and spring-loaded valve bridges to each of the two valve seats. The bridge is placed between the valve spindles and in the one end it is provided with a pressed-on thrust shoe and in the other end it is fitted with a thrust screw for adjustment of the valve clearance. On its top the bridge is controlled by a spherical thrust shoe on the rocker arm and at the bottom by a guide which rests in a spherical socket in the cylinder head.
Governor
The engine speed is controlled by a hydraulic governor. The purpose of the governor is to regulate the rate of delivery from the fuel pumps, so that the engine speed is kept within certain limits, in depending on the load. The governor is mounted on the flywheel end of the engine and is driven from the camshaft via a cylindrical gear wheel and a set of bevel gears.
Pick-up for Engine RPM
The pick-up for transfer of signal to the tachometer instrument for engine RPM is mounted on the flywheel end cover of the engine. A signal varying proportionally to engine RPM is created in the pick-up by the rotating toothed impulse wheel mounted on the camshaft end.
Regulating Shaft
The governor movements are transmitted through a spring-loaded pull rod to the fuel pump regulating shaft which is fitted along the engine. The spring-loaded pull rod permits the governor to give full deflection even if the stop cylinder of the manoeuvreing system keeps the fuel pump regulating shaft at “no fuel” position. Each fuel pump is connected to the common, longitudinal regulating shaft by means of a two-piece, spring-loaded arm. Should a fuel pump plunger seize in its barrel, thus blocking the regulating guide, governing of the remaining fuel pumps may continue unimpeded owing to the spring-loaded linkage between the blocked pump and the regulating shaft.
Stop Screw for Max. Delivery Rate
The bracket for stop cylinder/limting cylinder is fitted with a stop screw which prevents the fuel pumps from being set to a higher delivery rate than what corresponds to the permissible overload rating. This is effected by the arm on the regulating shaft being stopped by the stop screw.
Mechanical Overspeed
The engine is protected against overspeeding in the event of for instance, governor failure by means of an overspeed trip. The engine is equipped with a stopping device which starts to operate if the maximum permissible revolution number is exceeded. The overspeed tipping device is fitted to the end cover of the lubricating oil pump and is driven through this
Crankshaft The crankshaft, which is a one-piece forging with ground main bearing and crankpin journals, is suspended in underslung bearings. The main bearings are equipped with insertion-type shells, which are coated with a wearing surface. To attain a suitable bearing pressure the crankshaft is provided with counterweights, which are attached to the crankshaft by means of two screws. At the flywheel end the crankshaft is fitted with a gear wheel which through an intermediate wheel drives the camshaft. Also fitted here is the flywheel and a coupling flange for connection of a reduction gear or an alternator. At the opposite end there is a claw-type coupling for the lub. oil pump or a flexible gearwheel connection for lub oil and water pumps.
Vibration Damper
In special cases a vibration damper is mounted on the crankshaft to limit torsional vibrations. The damper consists essentially of a heavy flywheel totally enclosed in a light casing. A small clearance is allowed
between the casing and the flywheel, and this space is filled with a highly viscous fluid. The casing is rigidly connected to the front end of the engine crankshaft and the only connection between the crankshaft and the damper is flywheel is through the fluid. Under conditions of no vibration, the casing and damper flywheel tend to rotate as one unit, since the force required to shear the viscous film is considerable. As the torsional vibration amplitudes increase, the casing follows the movement of the crankshaft but the flywheel tends to rotate uniformly by virtue of its inertia, and relative motion occurs between the flywheel and the casing. The viscous fluid film therefore undergoes a shearing action, and vibration energy is absorbed and appears as heat.