Engine oil serves two primary functions: lubrication and cooling. These are interrelated roles because proper lubrication will also enhance the cooling that is required in most applications. Now let’s see how oil meets each of these functions:
1. LubricationIn its simplest form, engine oil is meant to act as a lubricant to minimize contact between rubbing surfaces.
It separates two metal surfaces by forming a very slim layer between them and not only does this minimize wear and tear but also minimizes heat produced by friction.
Again, less friction is less heat, and this is the first way oil aids in maintaining the engine temperatures.
2. CoolingOil’s cooling role is much more straightforward and simple, although not as well-known as the other functions of oil.
When the oil is in the engine it lubricates moving parts and at the same time cools parts such as the crank shaft, the pistons, the cam shaft and the bearings.
These parts are exposed to high temperatures resulting from combustion and friction, and while coolant cannot penetrate many of these areas, oil can.
The metal surface of the oil transfers the heat to the oil and proceeds in its circulation to the oil pan or cooler.
In high-performance engines, this heat is usually removed by using oil coolers before the oil is circulated again.
This process is very important because if the oil did not take and dissipate this heat to the cooler parts of the engine, these components would get very hot and fail which would result in rapid wear of the components.
How Engine Cooling Functions with the Circulation of OilTo understand the mechanics behind oil’s role in engine cooling, let’s explore the oil circulation process:Oil Pickup and Pumping:The first process starts with the oil pan that contains the oil. Oil is pulled through the oil pan by the oil pump through a pickup tube and then forced through oil galleries, which are channels within the engine block and head.Heat Absorption:The oil circulates through the galleries where it performs functions such as lubrication and cooling of essential parts of the engine.
For instance, it supplies oil to the crankshaft bearings that move around per minute, and this is accompanied by a lot of friction and heat production.
It also cools the pistons and cylinder walls, which form the chamber where combustion takes place.Heat Transfer: After absorbing heat, the oil returns to the oil pan. In high-performance or heavy-duty engines, an oil cooler is often placed in this circuit to cool the oil further before it is recirculated.Cycle Continuation:
