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240 Landmarks TopGasoline and Natural Gas Engine > Daihatsu Oilmatic
 Daihatsu Oilmatic
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[Details of structure and function]
The engine had a type of oil pump in which the plunger rotates, advances and retracts. These motions took in and discharged oil. The plunger stroke was changed by the accelerator angle, and the discharged amount was increased in accordance with the increase of the load.
The engine was driven by the crank shaft from the pump. The oil taken from the oil tank was supplied to the intake manifold from one discharge outlet and to the crank shaft center bearing to the other outlet. The mixture ratio of gasoline to oil was controlled within a range from 25:1 to 80:1 depending on the engine speed and load so that optimal oil would be supplied continuously. Moreover, the quality of the lubrication was excellent because new oil was always being supplied. The oil was not diluted or misty like mixed oil but supplied to specified portions of the engine in droplets.
[Effect and progressiveness]
It was unnecessary to prepare mixed oil because the oil was stored in a special oil tank and supplied to various parts of the engine through the pump. The displacement of the accelerator angle was transmitted to the controlling cam of the oil pump to change the plunger stroke according to the engine load. Therefore, as the load increased, the supplied oil increased. The amount of oil consumption and white smoke were reduced by these mechanisms.
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Storage location:DAIHATSU MOTOR CORPORATION TECHNICAL ADMINISTRATION DIV. (1-1, Daihatsu-cho, Ikeda-shi, Osaka 563-8651)
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Year manufactured:1966
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Manufacturer:Daihatsu Motor Co., Ltd., Mikuni Corporation
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Classification:Design drawings, literature
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Current status:No example in storage: open to the public
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Model / Manufacture
Company name:Daihatsu Motor Co., Ltd.
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Familiar name:Daihatsu Oilmatic System
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Location:None
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Installation model:Daihatsu Fellow L37
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Year of manufacture:1966~1977
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Designed by:Daihatsu Motor Co., Ltd.
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Specification
Cylinder arrangement, number of cylinders:Inline 2-cylinder
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Cycle / cooling method:2/forced water-cooled circulation
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Combustion method:Hemispherical type
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Total displacement:356 cc
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Bore x stroke:62×59 mm
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Compression ratio:9
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Mass (weight):58 kg
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Performance
Max. output:16.9 kw [35 ps]/5000 rpm
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Max. torque:34.3 Nm [3.5 kgm]/4000 rpm
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Device
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Points of interest, topicality:The development of the Oilmatic System started when a separate lubrication method using a oil pump was employed in local tests preparing for exporting the Midget to the U.S. around 1958 because of the difficulty in obtaining mixed oil and white smoke emissions, etc.
At first, the oil was injected to the intake pipe. Later, the system was completed with better lubricating performance by the addition of forced lubrication to the crank shaft center bearing portion and discharged control of the pump.
The then-president Yuji Koishi opened this system to the automotive industry, and it is now used in motorcycles.
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Reference materials:Daihatsu Motor Co., Ltd., Service Dept., Sankaido Publishing Co., Ltd., Nov. 1967
"Daihatsu Fellow No Seibi", pp. 51-55.
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