Lubrication System

The lubrication system is a very vital link within the engine. There are two differnet ways of lubrication within different engines they are: the splash system and the pressure-feed system. The pressure-feed system is used in more modernized engines while the splash sytem is used in most fractional horse power and outboard engines. In this paragraph we will be talking about the pressure-feed system. In this system oil is forced by the oil pump through oil lines and drilled passageways. As the oil passes throught the drilled passageway it is under pressure and lubricates the crankshaft main bearings, the connecting rod bearings, camshaft bearings, piston-pin bushings, camshaft bearings, hvalve lifters, valve push rods and rocker studs. The cylinder walls are lubricated by the spinning of the connecting rod and piston bearins, as they spin oil is throw of and thus lubricating the cylinder walls. In some engines there are oil spit holes which line up with drilled holes and in revolution throw the oil against the cylinder walls thus another way of lubricating the cylinder walls.
For oil to be able to pass the drilled pasageways in the engine block to the crankshaft the main bearins need to have oil-feed holes which line up with the drilled holes in the crankshaft which line up each time the crankshaft turns. This is the same case for the connecting-rod bearings and the drilled passageways in the connecting-rod. The oil in the drilled passageways is under pressure so when the holes line up the oil is forced through them. After the oil has been forced into the required area it falls back down into the oil pan ready to be picked up again and circulated on and on. While the oil falls to the oil pan it is splashed against parts of the engine that need lubrication.
Now I'm going to go into detail about the splash sytem of lubrication. The splash system is only used on small engines such as a lawn mower engine or a small dirt bike. While the engine is running, dippers from the connecting rods enter the oil supply and pick up enough oil to lubricate the connecting rod bearings which will splash oil up to the top parts of the engine. When the oil is thrown it is something like a spray and then lubricates the cylinder walls and the pistons pins. The crankshaft main bearings are lubricated by small oil cups which catch oil and splash it again.
Main Parts of the Lubrication System
Oil supply - The main supply of oil which is held in the oil pan, this is poured into the case by the oil filter, and the amount you have in your engine is read by reading the graduated oil-guage rod also known as the dip stick.
Oil Pump - The oil pump is used to make the pressure needed to make sure all the oil is circulated to every part of the engine. It is customary for the oil pump to be submerged in the oil supply.
Oil Regulator and Relief Valve - This is used to free high pressure that has been produced by high engine speed. This consists of either a ball and spring or a plunger and spring.
Oil Filter - This is exactly what it says. It filters the oil. We need to do this because the oil is running through the engine all the time and it may pick up particles of stuff that can harm or break or scratch parts of the engine and the oil filter helps prevent this.


--->>Modern vehicle engines use a pressure or force-feed lubrication system where the oil is forced around the engine under pressure. Let’s look at gasoline engines first.
Oil won’t flow up into the engine by itself so a pump collects it through a pickup tube and a strainer, and forces it through an oil filter, then into passageways in the engine block, called galleries.
The galleries allow oil to be fed to the camshaft bearings, the valve mechanism, and the crankshaft main bearings. Holes drilled in the crankshaft webs allow the main bearings to supply oil to the big-end bearings.
After circulating through the engine, the oil falls back to the sump to cool. This is called a wet-sump lubrication system because the oil is kept in the sump ready for the next time it’s used.
Some special engines use a dry sump lubrication system. It uses all of the parts that make up a wet sump system and it lubricates the engine in the same way.
It differs from the wet sump system in the way the oil circulates. In a dry sump system, the oil falls to the bottom of the engine into an oil collection pan. A scavenge pump then pumps it to an oil tank where it is stored until the normal oil pump collects it and pumps it through the filter and engine in the normal way.
Because there is no oil storage sump under the engine, the engine can be mounted much lower than in a wet sump system.
The oil tank can be positioned away from the engine where it can get best cooling. And the amount of oil in the system can be much greater than in the wet sump system.
Diesel engines are lubricated in much the same way as gasoline engines but there are differences.
Diesel engines typically operate at the top end of their power range so their operating temperatures are usually higher than those in similar gasoline engines, so the parts in diesel engines are usually more stressed.
As a result, diesel oils need a different range of properties and are classified differently.
It’s common for some diesel engines to use an oil cooler to cool the oil in the engine. The cooler and oil filter are usually on the same mounting on the cylinder block.