Is it possible to "polish" engine oil?

Bertramdriver

Bertramdriver

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I'm just about to polish my diesel (many thanks to Rotrax) and got to thinking that with the price of 40 mono grade in Greece it could be worth reviving my engine oil by polishing it. Is it possible and what are the downsides?
If it's feasible I will make up my own rig and save serious wonga.
 
Ships use Glacier centrifuges but they also sample and have their oil tested to check the condition.

Diesel Engine oil has many functions one of which is a detergent that washes away build ups, combustion products etc and holds them in solution as well as holding particles, eventually engine oil loses its lubrication properties and does not protect the engine in the same way as new oil.

I would look for a more cost effective source for your oil rather than skimping on oil changes. Bear in mind oil samples are £30 a pop.

Cool a diesel engine and give it clean oil, clean air, clean diesel and regular maintenance and inspections and it will serve you well .
 
Bandit said:
Cool a diesel engine and give it clean oil, clean air, clean diesel and regular maintenance and inspections and it will serve you well .
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Although it was an interesting question to post. This sounds like very clear and good advice to me.:encouragement:


RR
 
RogerRat said:
Although it was an interesting question to post. This sounds like very clear and good advice to me.:encouragement:


RR
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+1 lots. Your engines are the most expensive component in the boat. An oil change is not a huge amount of money. My engines take 50 litres between them, and I use the best recommended oil. Total cost inc filters is £150 ish. Far from a significant cost in my boating.
 
Think you'll burn more $$ building the rig than what years of supply would cost you ...

Monograde should not be in short supply in Greece as those lumps are all over the place .... have you spoken to ;

BP OIL HELLENIC SA, 26 Kifissias Ave & 2, Paradissou str., uMaroussi, Athens 15125
Telephone 30 210 6887 - 111
Fax 30 210 6887 698

and asked for the cost of a couple of 20L drums of their Tection DD Monograde 40 ... or if they have a local supplier in your area? ... set me back approx. £120 here for 40L .... delivered to the boat.
 
Err.... I polish my oil all the time the engine is running....... I have a pump and a filter set-up built into my engine..... don't you??

(I'll get my coat!)
 
Jegs said:
I believe that is how large commercial vessels are operated: with a 24 hour system.

John G
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The short answer to can I polish my engine oil is yes, Scania commercial trucks have one system, plus there is a company that will supply a system ( I need to find their address) for example military vehicle in war can not stop to do a oil/filter change,,,,,plus many diesel engines run 24/7 all need a system,,,,
 
The key issue with oils used as the direct lubricant in any internal combustion engine is the exposure to the combustion process. Each sweep of the piston leaves a small film of oil on the cylinder wall and some of this oil burns during the power stroke as the fuel itself burns.

Mostly this leaves a minute carbon film, but also other products of combustion, and for this reason the oil contains a package of additves to control these products from damaging the engine, but after a period of operation these additives get used up. Primarilly this carbon exposure is why the oil in an engine rapdily gets black as soot. The filter removes any large particles, but will not replace the additives as they get used up.

Polishing diesel fuel removes contaminants to protect the finely machined injection pump and injector systems, which is why we filter the fuel in the first plce, but for engine oil just removing the particulates does not restore the additives, and for the relatively small volume in most boat engines a restorative system that wil maintain the fine balance of extras provided by the manfacturers is generally impractical.

The converse here is the gearbox oil which does not experience the contaminant exposure and generally lasts the life of the gearbox.
 
Thanks for all contributions to what has been an interesting thread. The conclusions I take away are that the Alison gear boxes can last a few seasons before the oil is changed whereas I'll probably stick to changing the engine oil every 100/150 hours or two years. However I'll change the filters each season.
Thanks for the contacts Alf. Clearly being a heavyweight commercial operator is more effective than being a penny pinching pensioner. I'll use the direct approach next time.
So, thanks all for your collective wisdom.
 
There is a MAJOR benefit if you change the oil at the end of the season as part of the storage regime. Because boat engines run cool the oil accumulates corrosion causing acidic combustion byproducts.

So if you change the oil you get rid of the problem.

I am on a sailie thing and some years only use the engine for 20 hours, however it still gets it's oil changed annually although I might skip the filter.
 
TQA +1

The other one people forget is the anodes in the engine, these need changing annually.

Skimping on oil and filter changes, impeller and anode changes, belt and air filter changes is in my mind a false economy and can be a recipe for disaster.

I assume you have a twin engine boat. I assume you have engines that are no longer in production. So if you have a catastrophic failure of one engine and it is beyond economic repair or major parts are not available then you may have to replace both engines and gear boxes. This is mucho expensive!

I have out of production engines and I look after them well, give them all the TLC I can, change out likely problems to future proof them and wrap them in cotton wool
 
Your Alison's have a good filter as well, so if you want to keep the gearbox oil longer, you could change the filter and pour out the oil in the canister and replace this now new straight 40... give you a top-up and gets rid of some of the pollutants...
I buy my oil from commercial outlets and they are very happy to deal with individuals and what appears to be relatively low volumes... and you have to remember that these guys also deals with fishermen, crane operators etc., so are quite used to sell lube in 20L lots....
 
Bertramdriver said:
I'm just about to polish my diesel (many thanks to Rotrax) and got to thinking that with the price of 40 mono grade in Greece it could be worth reviving my engine oil by polishing it. Is it possible and what are the downsides?
If it's feasible I will make up my own rig and save serious wonga.
Click to expand...

The oil we use is blended from " Bright Stock " supplied by refiners, with additives and chemicals put in for specific reasons.

The Ford Motor Co. supplied all its new UK built cars-untill the plant burnt down in Derbyshire-with reclaimed oil. In those relativly low tech days it helped the old generation cars run their engines in.

This plant, operated-IIRC- by Silkolene would centrifuge used oil collected from garages and repair depots and return it to bright stock.

The oil specialist who told me this also said that only REALLY high tempreture would damage bright stock beyond use. He demonstrated by heating some oil in a spoon with a welding torch. It turned into a charred sticky mess with a distinctive smell-a smell I can recall to this day.

So- it is possible to reclaim used engine oil, but only in large amounts and with pretty huge centrifuges.

For your small amount probably not worth it.

Hope you sort your tanks out!
 
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