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Junk Head
A junk head is a form of piston engine cylinder head, where the head is formed by a dummy piston mounted ''inside'' the top of the cylinder. In most other engine designs, the cylinder head is mounted on top of the cylinder block. That form has also been termed a "poultice head". It is essential for any piston engine to seal the joint between block and head. This is usually done by means of a head gasket, a flat gasket on the surface of the block. In early engines, the high pressures and high temperatures made this a difficult trial for the materials of the day and gasket failures were common. The junk head requires no head gasket and is sealed by piston rings inside the cylinder bore, as for the power piston. An alternative solution was the monobloc engine, where the block and head were formed as one piece. This solved the sealing problem, but complicated manufacture and maintenance. Particularly when routine maintenance still required frequent head removal for de-coking, on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knight Sleeve-valve Engine, Sectioned Head, Inlet Stroke (Autocar Handbook, Ninth Edition)
A knight is a person granted an honorary title of knighthood by a head of state (including the Pope) or representative for service to the monarch, the church or the country, especially in a military capacity. Knighthood finds origins in the Greek ''hippeis'' and ''hoplite'' (ἱππεῖς) and Roman '' eques'' and ''centurion'' of classical antiquity. In the Early Middle Ages in Europe, knighthood was conferred upon mounted warriors. During the High Middle Ages, knighthood was considered a class of lower nobility. By the Late Middle Ages, the rank had become associated with the ideals of chivalry, a code of conduct for the perfect courtly Christian warrior. Often, a knight was a vassal who served as an elite fighter or a bodyguard for a lord, with payment in the form of land holdings. The lords trusted the knights, who were skilled in battle on horseback. Knighthood in the Middle Ages was closely linked with horsemanship (and especially the joust) from its origins in the 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphite
Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large scale (300 kton/year, in 1989) for uses in pencils, lubricants, and electrodes. Under high pressures and temperatures it converts to diamond. It is a weak conductor of heat and electricity. Types and varieties Natural graphite The principal types of natural graphite, each occurring in different types of ore deposits, are * Crystalline small flakes of graphite (or flake graphite) occurs as isolated, flat, plate-like particles with hexagonal edges if unbroken. When broken the edges can be irregular or angular; * Amorphous graphite: very fine flake graphite is sometimes called amorphous; * Lump graphite (or vein graphite) occurs in fissure veins or fractures and appears as massive platy intergrowths of fibrous or acicular crystalline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
