Truths about Engine Oil Heating


Why do I need to heat the engine oil? We have an engine heater so I don’t need to heat the oil.

Heating an engine before use is great but it’s like only putting one shoe on! Only half the job is done! Sure any oil that is in the pan will get some heat transfer from the heated cooling system, but the oil inside a dry sump tank is still cold. What happens when you start the engine is that the oil pump tries to suck the cold oil from the tank into the engine. When oil is cold the viscosity is very thick. On a racing engine with tight clearances this could be catastrophic! It can cause bearing failure, valve train failure and excessive wear on the cylinder walls. Any failure will cost money! The thick viscosity of the cold oil may not allow it to flow through the tight orifices of an oil system meaning that the oil cannot lubricate the entire engine properly. Additionally, due to the high oil pump pressures it may get the oil to the top of the engine but when the oil tries to drain back unpressurised it takes an extended amount of time creating unwanted oil pooling in the cylinder head.

By heating the oil in the dry sump oil tank prior to engine starting will allow the oil pump to flow the oil throughout the engine as designed for optimum performance.

Should I only heat the oil at the start of the night?

Not always. Have you seen cars start a feature race and blow smoke for the first few laps? This can be caused by the oil losing temperature from the last race. The oil viscosity increases and is pumped to the top of the engine but is still too thick to drain back to the pan. All the oil is “stuck” at the top of the engine and finds a way to leak out the valve cover and drips onto the hot headers.

It is best to keep your oil warm throughout the nights racing. Oil heating all night is common in the Spring and Autumn months of the racing season but may be required in summer if the ambient temperature drops in the evening.

P1 Australia’s oil tank heat mats quickly allow you to heat the oil inside the dry sump tank to optimum temperature.