Accuracy & reference notes
This is an original educational reconstruction, not factory CAD or a service diagram. The belt follows the supplied diagram: crank → tensioner → central idler → water pump → alternator → upper idler → steering pump → A/C → crank. The tensioner is immediately photo-right of the crank. The duplex timing chain now wraps both intake sprockets, crank and balance shaft; Motion runs five times faster and moves the chain with its sprockets. The coolant hoses are omitted to expose the engine and front accessory drive. Two secondary-air combination valves are individually selectable: one at 11 o’clock from the water pump and a rebuilt left-bank valve. The previous high right-bank valve and the air-pump outlet hose are removed, and each bank has two cam magnets and two staggered cam sensors between them. The separate service-hardware and engine-harness assemblies have been removed. Castings, dimensions, tooth counts and detailed plumbing remain approximate.
Reference configuration: U.S. W211 E 350, rear-wheel drive, M272.964. E 350 4MATIC uses M272.972; its sump, mounts and surrounding packaging are not reproduced. “Front” always means the accessory-belt/radiator end; left and right are vehicle sides, not the viewer’s screen.
The current front-layout correction uses the supplied photograph and belt diagram, Daimler bulletin LI13.20-P-049041, and Mercedes M272 engine training. Mercedes M272 training photographs (slides 1, 6, 17, 19 and 30–31) guide the curved manifold housing, runner lobes, cover silhouette and neutral cast-metal finishes in this revision. The photographs are visual references, not dimensional measurements. The block now includes continuous valley walls, a balance-shaft roof and end bulkheads; the heads have broader cast shoulders and the front cover closes the central opening. These forms are reference-informed approximations. The lower crankcase has a contoured skirt and shallow casting reliefs. Fine grain, mild oxidation, joint patina and machined highlights distinguish the surface finishes. Miscellaneous vacuum/breather hoses and external actuator vacuum lines are omitted. The model is an approximation, not a photogrammetry scan. Cutaway surfaces are illustration sections; movement is not a firing-order or valve-timing procedure.
Primary online references:
Software: Three.js r160, MIT license. Original model and viewer created for this project. Mercedes-Benz is identified solely to describe the engine; this is an independent educational model.