Page 154 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

Petrol Mix Lubrication System: This method is used in two stroke engine of two wheelers is done. An oil sump
is not used to store the lubricating oil in this system. Lubricating oil is mixed with petrol in a suitable ratio of 20%
to 50%. Lubricating oil along with petrol enters the crankcase and combustion chamber to lubricate the piston,
piston ring, piston pin, cylinder liner, bearing and crankshaft.
• Splash lubrication system: This Lubrication Oil in the system is stored in a sump. A spoon-like scoop is
provided on the big end of the connecting rod. So when the engine rotates, it dips into the oil and as it rises, it
acts to blow the oil onto the cylinder liner. Also crankshaft, bearing, piston they also have lubrication. But the
valve mechanism, timing gear and external parts of the engine do not get lubrication. So this method is not
used in automobiles
• Dry sump lubrication system: In this method oil is not stored in the sump. Hence it is called dry sump
lubrication system. There is a separate tank for oil storage and an oil pump is used to deliver the oil from the
sump to the tank and another pump is used to supply the oil from the tank to the engine. Even if the engine
reverses, there is no interruption in the supply of lubrication oil. This method is used in airplanes, racing cars
and ships. Pumps that draw oil from the sump are also called scavenging pumps.

• Pressure Lubrication System: Pressure Lubrication of engine parts are done by sending lubricant under
pressure in the system. Oil is stored in a crankcase. The oil pump in the oil sump draws it through the strainer
and sends it to the filter at the correct pressure through the pressure relief valve. The pressure of the oil sent
by the oil pump is 2 kg. / cm to 5 kg. / cm There is so much. From the main gallery, the oil enters the crankshaft
main journal and crankpin. The big end of the connecting rod is mounted on the crankpin. Lubrication of
the piston also takes place through the connecting rod. Some of the oil splashes from the crankshaft main
journal fly onto the cylinder wall to lubricate the cylinder wall. Also a separate internal passage is provided
for conveying the oil from the main gallery to the rocker arm. Pressured oil through these passages supplied
each rocker arm goes Some of the oil dripping down provides lubrication to the valve stem and guide. Also, a

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CITS : Automotive - Mechanic Diesel - Lesson 39 - 46 CITS : Automotive - Mechanic Diesel - Lesson 39 - 46