early diesel head

[flightlessbird]

Does an early diesel cylinder head have combustion chambers machined into them?

[gtimk5]

No, definately not.

[brackie]

Like most diesel heads the 1.5D head is flat with only a small combustion space in the top of the piston. This is there more to provide clearance for the valves than space for combustion. Some direct injection diesels have a larger chamber in the piston crown.The 1.5D has precombustion chambers that provide not only the "swirl" needed for efficient distribution of the diesel mist from the injectors but also enough volume to allow for the heated air/fuel mix to ignite. This makes for a "softer" ignition that on older engines enables the precombustion chamber diesels to run more quietly than direct injection diesels. That all seems to have changed with the VW direct injection motors