Lubrication System Parts and Functions

Without access to the engine’s moving components, even the greatest oil is worthless. In order to deliver oil to the engine’s moving components, the 4 stroke engine lubrication system must be properly designed.

In the latest of our continuing series on automotive lubrication basics, we’ll discuss how the oil system in a car functions. Also, we’ll present a specific brand of synthetic motor oil that may extend engine life to as much as 350,000 miles!

How Oil Works

When oil is introduced into a bearing, it spreads between the bearing surface and the shaft, forming a film that isolates the components. The components then rotate independently of one another. When the engine is turned off and the oil supply is cut off, the shaft settles into the bearing, forcing the oil film apart.

A little amount of residual oil (oil that adheres to the components) will be preserved. Moving parts are limited to a certain extent by the top of the film that touches the shaft journal, as well as the bottom of the film that contacts the bearing. Oil slides over the surface of the film at a point near the middle of the film.

This sliding motion enables the journal to rotate freely while remaining free of contact with the bearing surfaces. For the initial few seconds of operation, the shaft will only be lubricated by residual oil. Consequently, once the oil light or oil pressure gauge needle starts rising, motors should be permitted to idle in park or neutral.

In order to enable the oil to circulate properly in cold weather, more time should be allotted. Engine components such as the valve train and cylinders, which are subjected to the same load at all times, would not be adversely affected if the engine is operated before the motor oil is introduced. The following will be a discussion on engine oil lubrication system parts and functions.

“When used in harsh circumstances, AMSOIL synthetic motor oils are engineered to generate a long-lasting oil layer that protects hard-working engines from heat and damage. AMSOIL synthetic engine oils are designed to help engines run at top efficiency and for the longest possible life.”

What is Bearing Clearance?

All bearings must have the proper clearances in order to function properly. The proper bearing clearance is determined by striking a balance between oil flow and pounding resistance in the bearing. In fact, the oil clearances are only.002″ (0.05 mm).

Three Types of Lubrication Systems

Three distinct lubrication methods are used to lubricate the engine bearings and the rest of the engine’s moving parts. They are as follows: Combination Pressure-Splash System, Splash system, and Full pressure system.

Combination Pressure-Splash System

The crankshaft and camshaft bearings are lubricated by the use of an oil pump in this arrangement. Engine components and other elements are lubricated by the movement of the crankshaft. To keep the cylinder walls, piston pins and other parts lubricated, connecting rod oil spurt holes are employed to disburse oil.

The cylinder head also receives oil injection to ensure that the camshaft, rocker arms, and valves are properly lubricated as required.

The rocker arms and valve stems are lubricated by the pressurized oil that shoots out of the pushrods. The timing gears and chain may be lubricated using a nozzle. A dipper is sometimes used in combination systems to squirt oil.

Splash system

Dippers are attached to the bottom of the connecting rods in the most basic splash system, which distributes oil to the moving components. Dippers like this may be used in shallow trays or directly into the sump. The oil is sprayed all over the engine’s interior by the rotating dippers. Oil is pumped into the connecting rod bearings via the dipper’s holes.

To ensure that the oil trays are never empty, an oil pump might be utilized. Engines with only one cylinder employ the simple splash system.

Full pressure system

As one of the different types of lubrication systems, the full pressure system has been in use for years. An oil pump is used to take oil from the oil pan, which is then used by the full pressure system. Afterward, the pump pumps oil via drilled and cast tubes, known as oil galleries, to reach the journals of the camshaft and crankshaft.

In order to keep the connecting rod journals well lubricated, the crankshaft is bored. To enable oil to reach the wrist pin bushings, some engines drill their rods to their entire length. Using spurt holes in the rod to lubricate the camshaft lobes and cylinder walls may aid in bearing throw-off.

It’s also important to lubricate the timing gears, chains, rocker arms, and pushrods. Bearings in the pressure system are lubricated by either pumping oil into the bearings or by squirting or dripping it on. Additionally, the lubricating system supplies the hydraulic lifters with the pressure they need to operate.

Components of the Pressure-Splash System

It is virtually universally recognized that the pressure-splash combination system best satisfies the requirements of current engines. Of the types of lubrication systems in automobiles, this one rates highly. Oil is continually being pulled from the bottom of the engine, pressured, and delivered to the various engine components in a continuous stream.

The oil then drops to the bottom of the oil pan sump, where it completes the circuit once again and starts the process all over. This has become the most popular 4 stroke engine lubrication system. Next, let’s dig deeper into the oil system in a car and components of engine lubrication systems.

“In order to keep engines clean and operating correctly, AMSOIL synthetic motor oils are specially designed to prevent oxidation and sludge development. They also have a high resistance to thickening, allowing them to provide the best wear protection.”

What is an Oil Pan Sump?

The next engine lubrication system components area we’ll discuss concerns the oil pan sump. Oil is put into the engine first, after which it drains into the oil pan reservoir. Sump is a term used to describe a reservoir formed when one side of an oil pan is lowered to produce a reservoir.

It is common to utilize baffle plates and screens to keep the crankcase oil from sloshing about and hitting the crankshaft. The drain plug is inserted into the sump’s side or bottom.

What is an Oil Pickup?

The majority of engines have a stiff pipe that leads down into the sump’s oil. To prevent gathering up sludge, the oil pickup does not come in contact with the bottom. There are certain instances when engines with floating pickups are employed. This pickup floats on top of the oil and draws only from the sump’s top.

A vital element of the operation is to lower the pickup in order to keep the flow of oil consistent. To prevent bigger particles from entering the system, all oil pickups are equipped with screen filters. A tiny valve may be included that will be pulled open in the event that the screen gets blocked, enabling the pump to circumvent the screen and gain access to the oil.

Types of Oil Pumps

An oil pump plays a critical role in the oil system in a car. Engine oil pumps may be broadly classified into three categories. The gear, rotary, and vane pumps are among them. The gear and rotary types are the most often utilized in the industry.

Gear Pump

The moving force for the gear pump is provided by the driving and driven gears. All of these gears are contained inside a small enclosure. Unlike the driving gear, which spins on a small shaft, the driven gear is attached to a long shaft. It is spun by a spiral gear that meshes with a gear that is similar to that on the camshaft.

Both gears’ teeth must mesh with the smallest amount of clearance possible. The housing is just slightly larger than the top, bottom, and sides of both gears and does not interfere with their operation. An intake pipe enables oil to be sucked into the gear teeth by the rotation of the gear teeth. A vacuum is created by the teeth moving apart on the inlet side, which sucks oil into the system.

The oil is transported around to the opposite side of the tank. Oil is pressurized when the teeth move together, and the pressure causes the oil to discharge out the pump outlet. After that, the pressured oil is introduced into the remainder of the lubricating system. This kind of pump is very efficient and can provide high pressure and flow as required.

“Depending on the engine operating temperature, certain motor oils might boil out, or volatilize, increasing oil consumption and detrimental engine deposits, resulting in less wear protection and fuel efficiency. Using thermally stable base stocks found in AMSOIL synthetic engine oils ensures that your engine runs cleanly and efficiently at high temperatures.”

Another kind of gear oil pump has two gears, one of which has internal teeth and the other which has external teeth, both of which deliver oil to the pump in turn. The motor oil is delivered through the filter block and into the gear teeth with each rotation of the gears. These deposits of motor oil may be visible in the output region. There is no route for oil to escape due to the meshing of the gears, and as a result, pressure rises, forcing the oil out through the outlet.

Rotary Pump

A rotary pump is composed of three components: a housing, an inner rotor, and an outer rotor. The outer rotor is shaped like a star with rounded tips. The inner rotor is fashioned like a cross with rounded tips that fit within the star of the outer rotor. The inner rotor is much smaller than the outer rotor. It is powered by a camshaft-driven shaft. To make the star-shaped outer rotor move around in the inner rotor, the inner rotor is positioned off-center.

As a result, the outer rotor spins as well. Oil flows into and out of each of the outer rotor’s intake and outlet ports as the inner rotor traverses the outer rotor. As the inner and outer rotor points get closer together, it is pushed out. Because the inner rotor fits securely against the outer rotor at a single point, the oil cannot circulate around the rotor.

Vane Pump

The vane pump is comprised of a circular casing with a rotor that is offset from the center. This rotor is comprised of two or more vanes, also known as rotor blades, that are designed to fit into slots in the rotor. The vanes are kept out against the spherical housing by springs located between the vanes and between the housing and the vanes.

Some designs provide oil to the inner vane ends under pressure, whereas others do not. This pressure, along with centrifugal force, aids in maintaining strong contact between the vanes and the housing wall. In order to maintain the vanes in contact with the housing, the shaft rotates, causing the vanes to move in and out.

They produce a vacuum that sucks oil into the input port as they travel outward. Pressure is built up in the oil as the vane is pushed in on the opposite side, causing it to be pushed out. Oil is produced when a continuous charge is taken up, transported, and squeezed out by the pump.

“Unlike conventional engine oils, AMSOIL synthetic motor oils have low pour points, enabling them to stay fluid at temperatures as low as minus 53 degrees F. Their improved cold temperature fluidity makes cold-weather starts safer and enables the oil to move more rapidly through the engine for quicker and improved protection.”

How a Pressure Relief Valve Works

It is possible to achieve pressures significantly in excess of those required for lubrication with an oil pump in excellent working order. Oil is transported by the pumps in substantial volumes; however, when the useable pressure limits are reached, a pressure relief valve opens, allowing oil to flow back into the reservoir.

Relief valves enable a certain pressure to be maintained in the bearings. Pressure may be increased or decreased by adjusting the spring tension. If the relief valve isn’t close to the pump, it might be placed anywhere in between the pump and its bearings.

Oil Galleries and Lines

The networks & pathways that are found in the oil system in a car are called oil galleries and lines. The oil that is permitted to enter through the pressure relief valve is transported to the bearing via the oil galleries.

The block’s central oil gallery extends longitudinally and is linked to the majority of the other galleries. The majority of engines have two or three plugs located at the rear of the block near the end of the main gallery. If you’re doing an engine overhaul, you should take the plugs out and clean the gallery out.

Bearings are connected to the main gallery by drilled passages. The crankshaft has holes bored into it to allow oil to flow from the main journals to the rod journals. Parts of the oil flow are transported through different lines in certain engines. Oil is carried to the wrist pins on certain rods by drilling all the way through their length. Some feature small holes that match up with the journal of the crank once per rotation.

Oil is squirted through the spit hole and onto the cylinder wall when the two holes align. In certain engines, spit holes are also utilized to lubricate the camshaft lobes. Oil is applied to the timing chain in a variety of ways, including spray, oil released from the No. 1 camshaft bearing, and oil sprayed from an oil nozzle.

When operating overhead valve engines, oil is sprayed into the valve train, and in the case of reciprocating engines, oil is injected into the rocker arm shaft, through the rockers, and into the valves. By using hollow push rods, oil may also be delivered to the rocker arms.

Certain engines do not use rocker arms and instead control the valves directly through the camshaft lobes. Camshafts are lubricated by oil that is forced into their journals. Oil spray is used to lubricate the lobes.

“Each and every one of AMSOIL’s synthetic engine oils are designed to provide protection. The enhanced protection provided by certain AMSOIL motor oil families is so great that you may opt to lengthen drain intervals if you so choose, enabling you to change oil on your own schedule, save on maintenance, and minimize waste oil.”

How Oil Enters Bearings

The oil is supplied to the bearing via a hole bored through the bearing support. The insert has a hole that is aligned with the hole in the bearing support, and the insert may be removed. While the oil travels through the insert, it becomes engaged with and dragged around by the rotating journal. Some inserts have shallow grooves carved into them to aid in the spreading of the oil. Oil is pumped through the bearings on a continuous basis.

When oil is released from a bearing, it is pushed forcefully outward. This contributes to the production of fine oil mist inside the engine, which is beneficial for lubricating difficult-to-reach regions. All of the oil finally finds its way back into the reservoir or sump.

Hydraulic Valve Lifters

There are a variety of engines that employ hydraulic valve lifters. An oil-under-pressure-driven hydraulic valve lifter forces oil into the tappet when the valve is shut. Consequently, valve clearance is eliminated as a result of the plunger being extended in the tappet. In order to elevate the tappet, the camshaft lobe swings around and forces oil up into the lower chamber.

This seals the ball check valve, preventing oil from leaking out. This is because oil does not compress and so the valve is hoisted on a column of oil, which supports it when open.

“In order to minimize friction, AMSOIL synthetic motor oils are engineered to reduce friction, resulting in not only improved performance and protection, but also the most efficient use of gasoline. Engines are able to perform at full efficiency and give the most possible miles per gallon because of the reduced resistance to internal moving components.”

Pressurization in the lower chamber of the tappet is alleviated when the cam lobe moves from beneath the tappet and the spring forces the valve to shut as a result. The bottom chamber’s oil loss is compensated for by the lubricating system’s oil pressure.

Hopefully, this post helped in understanding the lubrication system parts and functions found in the oil system in a car.

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