pump clutch. The rotational speed controller is either an all-speed controller or an idle speed controller. The speed controllers are driven by the camshaft of the injection pump. The idle speed controller does affect the idle and redline speed only, while the all-speed controller affects every rotation speed. For fuel filtering a paper filter is used. Air compressor Engines for vehicles are equipped with an air compressor, to supply compressed air for the brakes. It is an air-cooled single-cylinder air-compressor driven by a belt. The air-intake is next to the engine intake manifold. The crankcase is not divided, the crankshaft is forged and has two ball bearings. The pushrod is housed in a needle bearing, the piston journal has a plain bearing pressed into the push rod bore. The piston has two piston rings and one oil control ring. Lubrication is done by a dry sump lubrication system, the compressor valves are poppet valves. Cold start system The cold start system has a solenoid valve and a glow filament which are connected in series. When starting the engine, diesel fuel comes through the solenoid valve and gets heated at the glow filament, the diesel fuel evaporates. It gets ignited at the last glow filament. The heat increases the temperature of the air from the intake manifold and makes it possible to start the engine unless the temperature level is not below -15 °C. Electrical system The engine is fitted with a starter motor, which is mounted on the crankcase at the exhaust side with securing clips. It is a 24 V direct current series-wound motor with a rated power of 4 kW. The three-phase current alternator has an electronic control unit. It is mounted on the exhaust side of the engine and is driven by a belt from the crankshaft. Technical specifications The engine was produced in seven basic variants. No specific names were used, instead engines were categorized after their intended use. Otto version In the mid-1980s, a prototype of an Otto cycle engine based upon the 4 VD 14,5/12-1 SRW was made. This engine, designated the 4 VOG 14,5/12 SRW, (4 cylinder, four-stroke, Otto, gas, stroke 14.5 cm, bore 12 cm, upright standing, in-line engine, water cooled) had spark ignition, a throttle valve, and was specifically designed for running on gaseous fuels, such as biogas and methane. Bibliography Authors of the VEB IFA-Motorenwerke Nordhausen: Dieselmotor 4 VD 14,5/12-1