Total-loss oiling system
A needle valve adjusts the rate of flow, which may be seen as drops passing through the window beneath the glass reservoir.
A total-loss oiling system was an early engine lubrication system wherein oil was added to a tank, passed through the engine, and was either burned or went out on the ground. It is still sometimes used in two-stroke engines.
Steam engines
Steam engines used many separate oil boxes, dotted around the engine. Each one was filled before starting and often refilled during running. Where access was difficult, usually because the oil box was on a moving component, the oil box had to be large enough to contain enough oil for a long working shift. To control the flow rate of oil from the reservoir to the bearing, the oil would flow through an oil wick by capillary action, rather than downwards under gravity.
On ships, that ran their engines for days at a time, members of the crew would act as oilers and might do nothing more than continuously check and refill oil boxes.
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With steam locomotives, where access would be impossible whilst running, centralised mechanical lubricators were developed where a single large oil box contained a pump with multiple outlets, feeding the engine's bearings through long oil pipes. Oiling the engine's internal valves was done by adding oil to the steam supply, that could be done through a displacement lubricator.
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Oil recirculation
The first recirculating systems used a collection sump, but no pumped circulation, merely 'splash' lubrication where the connecting rod dipped into the oil surface and splashed it around. These first appeared on high-speed steam engines. Later splash lubrication engines added a 'dipper', a metal rod whose only function was to dip into the oil and spread it around.
As engines became faster and more powerful, the amount of oil required became so great that a total loss system would have been impractical, both technically and for cost.
Splash lubrication was also used on the first internal combustion engines. It persisted for some time, even in the first high-performance cars. One of Ettore Bugatti's first technical innovations was a minor improvement to the splash lubrication of crankshafts, helping to establish his reputation as an innovative engineer.
A more sophisticated form of splash lubrication, long-used for rotating motor shafts rather than reciprocating engines, was the ring oiler.
Pumped oil
Later systems collect oil in a sump, from where it can be collected and pumped around the engine again, usually after rudimentary filtering. This system has long been the norm for larger internal combustion engines.
A pumped oil system can use higher oil pressures and so makes the use of hydrostatic bearings easier. These gave a greater load capacity and soon became essential for small, lightweight engines such as in cars. It was this bearing design that saw the end of splash lubrication and total loss oiling. It disappeared from nearly all cars in the 1920s, although total loss continued in small low power stationary engines into the 1950s. Chevrolet used splash lubrication for their rod bearings until 1953, where it was phased out for the 235 'Six,' and then in 1954 when the 216 was eliminated from their line, and both the solid lifter and hydraulic lifter versions of the 235 had full-pressure lubrication.
Two stroke engines and petroil mixtures
Small crankcase compression two-stroke engines use a system with petroil, where lubricating oil is mixed with the fuel beforehand. This mixture then passes through the engine's crankcase, lubricating the moving parts as it does so.
This is a total-loss system, although the same term is rarely applied as they are considered to be their own distinct system.