Description

It is critical to understand that an oil cooler is not designed to last the life of the car. Sound maintenance practice tells us that whenever we are doing a major engine overhaul, we should not fail to replace the cooler as it is almost impossible to get the debris and sludge out of a used cooler. You would not rebuild your motor with an old oil pump, nor should you reuse a cooler. This 13-row cooler is a direct replacement. In the past, fitting an oil cooler was mandatory once an engine had been even slightly uprated. The main cause for this was the quality of motor oils available at that time. If the oil temperatures exceeded a specific point engine failure was almost guaranteed. Modern motor oils are generally of a much higher quality, especially the ‘brand names’ and have far superior high temperature tolerance than those of 10 or 15 years ago. Fully synthetic oils have extremely high heat tolerance but not advisable for the mini gear box as baulk rings require different lubrication. Use of any type of synthetic type oils makes an oil cooler less of a necessity where engine outputs do not exceed about 90 horsepower. It is as bad to run the oil temperature too cool as it is to let it get too hot. The ideal operating range is 200 to 230 degrees F (sump temp). At these temperatures the oil is working efficiently to produce the best power, economy and release of combustion by-products. If the oil is too cool, these by-products are absorbed into the oil, requiring more frequent changes to avoid bearing and bore damage. It is worth noting that keeping the oil at the correct temperature helps cool the engine; high oil temperatures will create higher water temperatures. Therefore, fitting an electric fan for road use is more practical than an oil cooler.

Various sizes of oil coolers and fitting kits, including pipes, are available. To help control temperature there is a thermostat MOCOT1 that fits into the engine cooler pipes (cannot be used with braided steel pipes) that operates at 74 degrees C (165 degrees F). An oil temperature gauge adapter MOCOT2 is also available that fits into one of the cooler pipes, not compatible with the braided steel pipes.

A smaller 10 row cooler is available where temperature of the oil is not extreme. See MOC10ROW. The same applies to the water radiators-you need to keep the engine at the correct temperature and with all the varieties available beware of over cooling your engine. If you have not fitted an oil thermostat and only use the car for the road no matter what state of tune warm your car up gently to get the oil working at correct temperature and in the winter blank your oil cooler off.

Rover decided in 1991 that with current oils available the best solution was to fit an electric radiator fan to overcome any engine or coolant over heating problems. See C-ARA4401