Welcome to this article that highlights the fundamental differences between the two types of oil cooler. I don’t go over the subject of what size Laminova is equal to how many rows on a regular oil cooler or the difference in cost between the two – that sort of information is a by-product of the facts and whilst interesting it does not convey the real differences or values that each system has.
There are just three areas:
- Stamped Plate Oil Cooler
- Laminova Oil Cooler
- Thermostatic Oil Controls
The way in which heat is transferred to atmosphere and how that process is designed to take place is very different between the Laminova oil to water oil cooler and the well-known stamped plate oil to air oil cooler. I want to say at that I do not have an axe to grind with either type of oil cooler, they are both good, but ultimately very different in the way they deliver oil cooling.
Stamped Plate Oil Cooler
A traditional stamped plate oil to air oil cooler has a constant flow of oil through it and the heat being transferred to atmosphere is not regulated or controlled positively by any means. On a cold day it’ll transfer heat to atmosphere more than on a hot day for any given operational cycle. Fitting thermostatic controls to the oil supply does not stop the positive flow of oil to the oil cooler even when the oil is already cold (engine start up) – I explain why in the last paragraph on this page. When the engine is cold, oil is being cooled and when the engine is hot, oil is also being cooled. The result is that you have oil circulating through the cooler and being exposed to a constant unregulated atmospheric air temperature and supply that varies from day to day (the weather), regardless of the oil temperature it has the same atmospheric cooling influence applied to it. The oil flow and cooling medium (atmosphere) are unregulated with the primary method to tune oil cooling being the size of oil cooler. The result is that this can mean a lag in getting the engine up to operating temperature. More so on cold days and during the winter which is the opposite of what your engine really needs. It also means the oil cooling is independent of the thermostatically controlled engine coolant, this can lead to variations during the engines working cycle in temperature difference between oil and coolant. You will indeed cool your oil but it is not controlled or maintained with regard to the engines operational status in a harmonised way that the Laminova delivers.
Laminova Oil Cooler
The Laminova oil cooler or heat exchanger, allows a two-way migration of heat between oil and coolant whilst always having the overall target temperature maintained by the coolant thermostat and radiator. The result in normal use is less time to achieve engine operating temperature from cold start and oil temperatures moderated downwards towards that of the engine coolant temperature – what is referred to as ‘temperature harmonisation’. This helps reduce oil temperature spikes during competition and a more general reduction in oil to coolant temperature difference across the whole operating cycle.
It follows that the coolant radiator must be up to the job of dissipating to atmosphere the gross heat output generated in a controlled manner. The cooling system will need to have a radiator able to dissipate the total heat output being carried by the coolant. In all cases the radiator will have some sort of cooling fan to assist air flow. The ability to harmonise these temperatures and to transfer the heat to atmosphere in a controlled manner has a number of benefits:
- Quicker engine warm up from cold start.
- A reduction or levelling out of oil temperature spikes during peak engine demand.
- A general overall engine oil temperature reduction when engine oil temperature is above that of the coolant.
- Over cooling of the engine oil is not possible.
- Greater engine efficiency.
Thermostatic Oil Controls
I just want to explain why a thermostatic oil control does not stop oil circulating to your oil cooler when the oil is cold. I don’t want you to not use a thermostatic device, but I do want to you to know what it does and what it doesn’t do.
The thermostatic valve is a normally open (when cold) by-pass either within the sandwich plate or as an additional piece of equipment that fits into both oil lines (remote thermostat). These valves act as a safety feature when oil is below the temperature of 78C by allowing oil to by-pass your oil cooler. The thermostatic valve starts to close at 74C and is fully closed by 78C.
The thermostatic by-pass is designed to get enough oil to the bearings to stop any damage or excess wear should your remote oil cooler not allow oil to flow through it when below 74C. Your engine already has an internal by-pass in the oil pump to allow oil to get to the bearings should a blockage at any temperature occur. But the oil that by passes here isn’t filtered. The oil that goes through the thermostatically controlled by-pass still goes through the oil filter and that is a key difference, so much so that some engine builders will insist a thermostatic by-pass is used on any remote oil cooling that is then fitted by the user – a belt and braces approach to a problem that seldom occurs or is symptomatic of something more serious. The thermostatic by-pass isn’t that large and would struggle to maintain oil flow through the rev range if your oil cooler (for what ever reason) would not allow oil to flow.
At no time does the thermostatic control stop or restrict the flow of oil to and from your oil cooler, such a device is not commercially available that I know of. A thermostatic control of this sort does not and will not monitor or control the cooling effect of the oil cooler, this is not something it has the design capability to do. It is a safety feature for your lubricating system.
In summary, the thermostatic oil controls are safety features and not positive oil controls that a lot of people think they are.