BASE ENGINE


CYLINDER HEAD


ADVANTAGES OF 4-VALVE TECHNOLOGY



  • Greater inlet and exhaust valve cross sections assure an improved level of filling and thus an increase in performance and torque. The loss in charge pressure at changeover and loss in fuel are both reduced.
  • The symmetrical layout of the combustion chamber moulding and the vertically and centrally positioned unit injectors guarantee good mixture development and thus a reduction in exhaust emissions.
1.
 Roller rocker arm for unit injector
2.
 Unit injector
3.
 Inlet camshaft
4.
 Exhaust camshaft
5.
 Roller rocker finger for valves
6.
 Glow plug

TECHNICAL PROPERTIES OF CYLINDER HEAD



  • Cross flow head made from alloy material.
  • 4 valves per cylinder.
  • 2 inlet ports.
  • 2 exhaust ports.
  • Valve star is rotated by approx. 45 ° in engine longitudinal axis to assure optimal flow of port gases.
1.
 Inlet ports
2.
 Exhaust ports

  • Double overhead camshafts with 5 bearing points.
  • Both camshafts are driven together via one timing belt.
  • In addition to control of inlet valves, the inlet camshaft drives the front of the tandem pump in which the vacuum pump and fuel pump form one part.
  • In addition to exhaust valve timing, the exhaust camshaft drives the unit injectors.
  • Valve actuation is via rocker roller fingers that are mounted on a floating axle.
  • Valve clearance elements can be found, in contrast to other 4-valve engines, on the moving part of the rocker roller fingers.

1.
 Exhaust camshaft
2.
 Intel camshaft
3.
 Rocker roller finger
4.
 Floating axle
5.
 Valve clarence element
6.
 Oil channel
7.
 Sliding element

VALVE SEAT RINGS
1.
 Valve seat ring
2.
 Valve seat width
3.
 Additional chamfer

CYLINDER HEAD BEARING FRAME




  • Camshaft bearing points
  • Cylinder head reinforcement
  • Rocker arm shaft bearing point (unit injector drive)
  • Rocker arm guide (unit injector drive)
  • Support for cable channel of unit injectors and glow plug.
  • Good sealing properties to cylinder head cover by means of level sealing surface.
1.
 Bearing frame
2.
 "Bolt in bolt" connection

PISTONS



  • The 4-valve technology allows a central layout of the combustion mouldings in the piston crown.
  • By means of a reduction in the opening depth of the valves and a piston crown height of 9 mm, there is a reduction in the area in which harmful substances are generated, and thereby also a reduction in the emission of harmful substances.
  • The piston features a wave-type cooling channel.
  • Piston pin offset (0.5 mm) prevents tipping action of the piston at TDC to reduce noise generation.
1.
 Piston crown
2.
 Cooling channel

TIMING BELT DRIVE
1.
 Polyamide coating

TIMING BELT



TIMING BELT GUARD



TANDEM PUMP



VACUUM PUMP
1.
 Vacuum pump
2.
 Fuel pump

FUEL PUMP



  • The fuel pump operates on the principle of an inner gear type pump.
  • The maximum fuel pressure is regulated by a pressure control valve in the fuel supply system. It is set at 11.5 bar with an engine speed of 4,000 rpm.
  • The pressure control valve in the fuel supply system maintains fuel pressure at approx. 1 bar for return flow. In this way, a balanced proportion of forces is guaranteed in the solenoid valves of the unit injectors.
1.
 Return flow to fuel tank
2.
 Supply from fuel tank
3.
 Pressure control valve for fuel delivery
4.
 Fuel delivery to unit injectors
5.
 Return flow from unit injectors
6.
 Pressure control valve for fuel return
7.
 Strainer