One of the first items that enthusiasts or weekend racers add to their vehicle is an impressive set of engine gauges across the dashboard. Coolant temperature, turbo boost, oil pressure, tachometer, the number of gauges can be endless. The one gauge that is often overlooked is engine oil temperature. Maybe this is because it can be a bit harder to install, or is it due to the fact that most people don’t understand the importance of measuring engine oil temperature. Spending around $100 on a gauge, and a few hours of installation work, could save you the heartache of an engine rebuild and the thousands of dollars this can cost.
There are many characteristics of an engine oil that are affected by temperature and if you are looking to provide the best lubrication and protection for your high performance engine monitoring your oil temperature may hold the key. Oil temperature monitoring is not only recommended for the racetrack. Vehicles used for off roading, towing a heavy caravan or boat, or serious commercial work will all benefit from the knowledge that their engine oil is operating within its temperature limits
An oils ability to separate moving components inside your engine is determined by the oils viscosity. A high viscosity, or thick oil, can form a comprehensive fluid layer between components which reduces friction and prevents wear as this layer separates the surfaces. This is known as hydrodynamic lubrication. An oil with a lower viscosity, thinner oil, produces a thinner fluid layer between component surfaces and eventually if an oils viscosity is too low the surfaces begin to touch and this will create wear and friction.
The viscosity of an oil changes with temperature and as temperature rises oil becomes thinner and thinner. This alone is enough reason to install and monitor an oil temperature gauge. Even the best oils on the market have this characteristic of thinning under high heat and once your oil becomes too thin premature engine wear will occur, or in extreme cases dramatic engine failure may be the result.
When oil gets cold the opposite occurs and viscosity increases. This can cause problems to areas of your engine that require a good flow of oil to provide lubrication. Certain engine components are supplied oil by splash or spray mechanisms. Timing gears are an example of this. When an oil has thickened due to low temperatures the oil may not reach its intended location. A recent case that comes to mind involved two engine failures in a 3500 Hp V8 drag racing engine. The top end of the push rods are lubricated via spray mechanisms and investigations of the failed engines found that the oil spray had not reached the intended area because the oil was too thick due to the cold temperature on race day. An oil temperature gauge and the correct warm up procedure could have saved $20,000 worth of engine parts.
There are many other performance characteristics of an engine oil that are affected by its temperature as modern engine oils contain a vast array of complex additives. These characteristics, and how to manage engine oil temperature, This includes running an oil cooler and setting the car up to run at one temperature. we will also look at the pros and cons of a dry sump setup, will be discussed in future posts