Sack cylinder
A bag cylinder is a component in internal combustion engines ; it is manufactured in one piece as a cylinder and cylinder head in one piece, mostly as a cast part with mechanical processing.
To avoid failure-prone cylinder head gaskets , bag cylinders were often chosen in the early decades of engine construction. Their production is not easy, especially in the case of four-stroke engines , and advantageous combustion chamber shapes can hardly be produced with the relatively small possible valve angles; this is prevented by the space required for the processing tools, depending on the length of the bag cylinder (see sketch).
Bag cylinders were built for both air-cooled and water-cooled engines. In the case of water-cooled engines, the cylinder was partially provided with a sheet metal jacket to guide the cooling water. See also Mercedes-Benz MB 518 . One of the last car models with this design was the Panhard 24 , which was built until 1967 .
Sack cylinder of an NSU from approx. 1917, without inlet valve, with a decompression hand cock
Side view
Side view
From above, view through the intake valve opening onto the exhaust valve disc and into the combustion chamber
Accessibility when processing the valve seats on engines with bag cylinders
The pictures show a sack cylinder of an NSU with an IOE engine (“Inlet over Exhaust”; inlet valve above the exhaust valve) around the year of construction 1917. It is the front cylinder of a two-cylinder V-engine.