Oil & Detergents

[nimrod650]

not something i have done but my father always drained the oil replaced the bung put a couple of pints of parrafin into oil tank ran  the bike for 30 seconds then drained tank and crankcase and re- filled with castrol xl

[coater87]

 My dad did things like that too. Except he used about a half gallon of kerosene in the family car, poured it in on top of the old oil.

 He would fire up the Oldsmobile, let it run about 1 minute then drain the whole mess out.

 I think the job of cleaning out the sludge today is being done by the modern detergents in the oil we buy. I dont think this would do much for cleaning of the engine or be very good for it now. I think it would be like running it for one minute with sewing machine oil as the only lubricant.

[ellis]

Always used to add a pint of diesel engine oil in the car engine 100 miles before the oil change. Good detergents in diesel oil to keep the engine clean.

[muskrat]

The trouble with using a high detergent oil (or a solvent) in our motors is that if the sludge trap has any crap in it the detergent will wash it out straight into the bigend bearings.
Cheers

[beezermacc]

Ditto what Musky says. Do not, under any circumstances, do anything to flush the engine. The whole point of the sludge trap is to 'trap' particles before they have a chance to squeeze between the big end shells and crank journal surfaces. Any attempt to flush the engine will loosen the particles in the sludge trap and flush them through the big end shells...... instant death to the engine!

[BSA_54A10]

The trouble with using a high detergent oil (or a solvent) in our motors is that if the sludge trap has any crap in it the detergent will wash it out straight into the bigend bearings.
Cheers

Well no it won't.
The exact same certrifugal forces that caused it to collect in the sludge trap will keep it in the sludge trap only doubly so as it is being spun out of a thinner solution. Have a little think about it.

Next detergent oils are not penetrant, degreasers scourers, or solvents and will do absolutely nothing to "clean" up an old dirty engine.
A detergent, like the one you use on your dishes simply attaches to anything and everything else that is not a detergent.
In an oil the detergent addative does nothing more than envelope tiny particles of anything that is not oil so that they can not join together and become big lumps of crud commonly called sludge but stay as fine particles suspended in the oil so that the filter can remove them easily.
They will not brake up the sludge in the sludge trap unless they are being forced through the oil galleries at hundreds of PSI and many gallons per minute while the crank is stationary.

You don't usually put high detergent oils in engine with full flow centrifugal oil filters because the two work against each other.
The one is trying to force all of the particulate matter into a big solid lump in the sludge trap or setteling tank while the other is trying to keep all of the particulate matter as discreet particles so they can be strained out easily by the filter.

A detergent oil KEEPS THE OIL CLEAN it does not CLEAN A DIRTY ENGINE,

Adm edit: moderated, some content removed.

[bsa-bill]

The detergent in oil does not keep the oil clean, the filter does that (which should be employed when using  such oil)

[muskrat]

I know you know what your talking about Trevor but I do have to differ a bit here. Not from any scientific knowledge but form experience. I have seen many an OLD Holden/Ford (OK their not A7/10 BSA's) motors destroyed by using diesel type oils washing away the years of built up crud, blocking oil ways and strainer.
 
Cheers

Don't really want to start another oil thread!)

[mugwump]

I have to confess to ruining a Ford Zephyr engine many years ago by using flushing oil. Just thought it was a good idea at the time, before an oil change. Engine sounded like a bag of nails afterwards.

[East_Coast_BSA]

Motor oil with detergents include chemicals that aid in trapping particles, dispersant additives that break down coagulating sludge in channels, rust preventers and alkaline to offset the acidic nature of oil in general as it begins to oxidize.  If you run detergent oil in a vehicle (such as older farm equipment for example) that has previously spent it's life on a steady diet of non-detergent oil, it will leak most everywhere (especially around the seals).  It will also loosen sludge deposits and clog small galleys and passageways.  I've seen it happen more than once.  BTW, I'm not a member of any of your "categories" either.

[nimrod650]

i remember i used to buy a 5 gallon drum of green duckhams from a rep very cheap he used to say they would never make a racing oil as the green standard oil was good enough for racing engines i remember  doing an oil test at tech  were a drum with large ball bearings was spun at high speed till they stuck together due to the oil failing duckhams came out on top every time beating all other  well known brands

[chaterlea25]

Hiya
Duckhams ! sadly missed 

John

[BSA_54A10]

I know you know what your talking about Trevor but I do have to differ a bit here. Not from any scientific knowledge but form experience. I have seen many an OLD Holden/Ford (OK their not A7/10 BSA's) motors destroyed by using diesel type oils washing away the years of built up crud, blocking oil ways and strainer.
 
Cheers

Don't really want to start another oil thread!)

In a wet sump situation the sludge formed is quite loose.
I am sure you have cleaned out a sump or two in your time.
The goo that blocked off the oil pick up screen was an emulsion caused by one addative package being incompatiable with another addative package and generally a redox type reaction

[BSA_54A10]

Motor oil with detergents include chemicals that aid in trapping particles, dispersant additives that break down coagulating sludge in channels, rust preventers and alkaline to offset the acidic nature of oil in general as it begins to oxidize.  If you run detergent oil in a vehicle (such as older farm equipment for example) that has previously spent it's life on a steady diet of non-detergent oil, it will leak most everywhere (especially around the seals).  It will also loosen sludge deposits and clog small galleys and passageways.  I've seen it happen more than once.  BTW, I'm not a member of any of your "categories" either.

Yes of course they do.
All motor oils contain those and a lot more such as surface tension modifiers also called anti- foam agents, plasticisers to aid keeping rubber seals soft, anti emulsification agents to allow small amounts of water to be boiled off and not held in suspension in the oil. I could go on but this is getting too long already

From Lubricants , Cutting Fluids & Coolants  by W.J.Olds which was the text book my students had to  use.
Glossary, page 193

DETERGENT :- In lubrication either an additive or a compounded lubricant having the property of keeping insoluble matter in suspension thus preventing its its deposition where it would be harmful. A detergent may redisperse deposits already formed.

DISPERSANT ;- In lubrication a term usually used interchangeably with detergent.

All detergents are dispersants.

If you can read it on Google books then I suggest you read chapters 3 ( The miracle of additives ) and chapter 17 ( the myths about motor oil ), I have & I have taught it for several years. If you can find a copy the other books we used were "the anatomy of modern oils" and "the chemical compatability of additives in oils & greases "
I could not put my hands on them right now so they may be out on loan.

[duTch]

 So Trev, I don't wish to go further off the G-glitter story, and could ask a few questions other than what do you know about Abiotic oil? - maybe not to be answered here