OIL FILTERATION SYSTEM

[T.A]

My marina chandlery have advised me of a new oil filteration system called, "Purgemaster" with all the associated benefits? Does anyone have any experience of this system?

[John Orentas]

The guys in TW Marine showed me one and told me a bit about the system.

 

A small percentage of the oil that passes around your engine is forced through an ultra fine filter material which takes out a massive percentage of the particles, it can extend your oil change intervals by a factor of up to four.. It seems many hire firms have started using them, not that they are that new, haulage companies have been using the system for many years.. But new to boats !

[Yoda]

I would be very guarded using a very fine filter without a pressure differential guage across it. Even if it only filtered part of the oil flow it is liable to block up very quickly on an old engine or one that's running on synthetic /chemical oil.

[onthecut]

Hi. T.A.

 

I understand the idea of removing particles, but if you considerably extend the time the oil is in the sump, does its detergency factor not diminish, plus the oil gradually become acidic ?

 

Mike.

[Yoda]

Modern oils are very good at scavenging dirt from around the engine. This is especially true of synthetic/chemical oil. If used constantly these oils have a very long life in what are very low-stressed engines. The main point is to get them hot enough to boil any water out and filtered to remove any carbon from combustion. Fine filters will extend the life of the oil as particles are held in suspension and cause wear on the motors metal parts.

[Sir Nibble]

it can extend your oil change intervals by a factor of up to four..

 

Oil reaches the end of it's life because the long chain polymer molecules are broken. No amount of filtration will alter that, and if your oil really needs changing 'cos it's full of crap, the engine needs a flush. What is the saving anyway between changing a filter full of particles over changing oil full of particles?

[Yoda]

I know that I would be happier to change a filter than change a high spec oil frequently. It is true that the oil life is limited by polymer breakdown but this is now something like 10 times longer than it was thirty years ago. Oil should now be 'on condition' and usage. That means light usage and gets hot equals long life. Assuming its relatively clean and well filtered, I will not change it. However in my turbocharged engine it is the temperature of the oil in the turbo bearings that limit the life of the oil. Therefore it requires changing more frequently even though it is well filtered. All of the above assumes that an oil of the highest spec is used.

[onthecut]

Hi Yoda.

 

Think you have hit one of the nails on the head there. Those with older, low revving units simply don't use modern, high spec, high design temperature oil. I suspect if you're in the 'CC' spec. camp, you will still be better off -- in every sense -- using a cheaper diesel oil and changing it regularly.

 

Mike.