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Complete Engine -- Basic Knowledge -- 215 & 220 Chassis Mercedes-Benz Pullman W221

Mechanical 3 illustrations ~558 words

General information on complete engine - GF01.00-P-9611AA

ENGINE 137.970

General

Engine 137.970 is a V12 gasoline engine with a cylinder angle of 60° which supersedes the previous V12 engine 120.982.

In the interests of significantly lower fuel consumption, reduced pollutant emissions and a more compact construction, the displacement of the new V12 has been reduced and the rated output and maximum torque decreased. Thanks to the lower vehicle weight and lower air resistance of the ranges C215 and W220 the performance is superior to previous ranges in part.

The advantages of the new V12 engine compared to the engine 120 are characterized by the following points

  1. Fewer pollutants in exhaust gas
  2. Lower fuel consumption (up to approx. 20% lower)
  3. Lower weight 220 kg (24% less = approx. 70 kg)
  4. More compact construction (overall height reduced by 36 mm, overall length by 49 mm, overall width by 144 mm)
  5. Lower noise emissions and engine vibrations

This is also achieved by

  1. Cylinder shutoff (ZAS)
  2. Three-valve technology
  3. Two spark plugs for each combustion chamber
  4. Phase-offset, alternating dual ignition
  5. Ignition misfire recognition via ion current diagnosis
  6. Increased compatibility to residual gas
  7. Air-gap insulated exhaust manifold with new inner pipe technology
  8. IHU (Internal High-pressure Conversion)
  9. Quadruple three-way catalytic converters in Double Layer Technology with eight lambda sensors.
  10. 4-flow exhaust system with quadruple lambda control
  11. Reduction in drag friction
  12. Split crankcase (bedplate construction)

The exhaust emissions meet the exhaust emission limits in accordance with EU 4 which apply to Europe as of 2005 and also still have the necessary potential to be able to meet future limits.

With regard to improving the torque curve, an extremely compact ram intake pipe (not a variable geometry intake pipe), which ensures a particularly uniform torque curve has been developed using sophisticated three-dimensional flow calculation. The valve gear with one camshaft for each cylinder bank operates two inlet valves and one exhaust valve via roller rocker arms and valve clearance adjusters.

Cylinder head, generalGF01.30-P-9611-01AA
Crankcase, generalGF01.40-P-9611-01AA
Connecting rod, generalGF03.10-P-9611-01C
Crankshaft, generalGF03.20-P-9611-01AA
Valve gear, generalGF05.30-P-9611-01AA
Ignition system, generalGF15.10-P-9611-03AA
Engine lubrication components, generalGF18.10-P-9611-01AA

General information on cylinder head - GF01.30-P-9611-01AA

Cylinder head

Made from a chilled casting with three-valve technology and cross-flow cooling. Two inlet valves and one exhaust valve are controlled by one camshaft for each cylinder bank via low-friction roller drag levers. Hydraulic valve clearance adjustment is fitted as previously.

Two long-life spark plugs are screwed into each combustion chamber on the exhaust side.

Identifying Cylinder Head. Scheme 415

Scheme 415: Identifying Cylinder Head

Identifying Cylinder Head. Scheme 416

Scheme 416: Identifying Cylinder Head

Identifying Crankcase And Oil Pan Components. Scheme 417

Scheme 417: Identifying Crankcase And Oil Pan Components

Crankcase

Split into two (bedplate version) made from aluminum pressure diecasting, upper section (1) with aluminum/silicone cylinder liners and upper halves of crankshaft main bearings. The lower section (3) with the lower halves of the crankshaft main bearings.

For reasons of vibration technology the crankshaft main bearings are produced from grey cast iron and screwed into the top and bottom halves of the crankcase.

In spite of cylinder liner technology with a cylinder spacing of 90 mm, an extremely narrow cylinder land of 6 mm was achieved, contributing to lightweight construction and compactness.

No repair sizes for the cylinder liners are planned.

The tolerance subdivision for top main bearings and piston are marked under the left engine support and on the engine support flange. The engine number is stamped on the transmission flange behind the right cylinder head.