Modern Oils

I read somewhere that modern detergent oils when used in old motor dissolve the crap in the motor and distribute it. Surely it would be OK in a reconditioned, clean engine ? Or does it adversely affect the Norton oil seals ?

acotrel said:

I read somewhere that modern detergent oils when used in old motor dissolve the crap in the motor and distribute it. Surely it would be OK in a reconditioned, clean engine ? Or does it adversely affect the Norton oil seals ?

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I have seen no adverse affects. Jim

acotrel said:

I read somewhere that modern detergent oils when used in old motor dissolve the crap in the motor and distribute it. Surely it would be OK in a reconditioned, clean engine ? Or does it adversely affect the Norton oil seals ?

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Same for aircraft engines before they went to detergent oils. You were "allowed" to go to the better oils only after a complete teardown, typically once it reached max hours for an overhaul. That way, the years of grime adhering to the innards didn't come loose in one gigantic mess inside the engine.

Nathan

"Detergent" was probably a poor choice of a term to name these oils when they first came out. The difference between them and nondetergent oil is their ability to hold the soot particals that are the byproduct of combustion in suspension. These are too small to be trapped in an oil filter. The reason these oils seem to turn black so quickly is because they are holding all this potential sludge in suspension. With the nondetergents this would have built up inside the engine. They have no solvent ability and don't "scrub down" the inside of an engine.
Besides they have been the predominant type available for the last 40 years. Unless you are the original owner chances are any old Brit bike that has been ridden at all during that time has had detergent oil in it.
I've run two old Brit bikes on detergent oils without rebuilding the engines and run it in the Norton that has had a rebuild. No problems.
Now I do run motorcycle specific oil and not car oil but that is another discussion.

The oil filter (If your bike has one) should catch any swarf that might break free.
The bottom of the oil tank is probably the worst offender.
My Atlas motor innards were "clean as a hounds tooth" when I tore it down.

Pretty sure they still use detergent-dispersant (DD additives) in modern oils.

acotrel said:

I read somewhere that modern detergent oils when used in old motor dissolve the crap in the motor and distribute it. Surely it would be OK in a reconditioned, clean engine ? Or does it adversely affect the Norton oil seals ?

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How much riding of old bikes have you actually done?

That post makes me think "not much."

Modern " detergent' oils came out in the late 60"s, so you have always had the opportunity to use them. Like it says above, they hold the soot in suspension. When they first came out, Caltex didn't mention it to the mechanics, [ or someone didn't pass the info on ] , so when the used it for the first time, it turn black before the vehicle left the workshop. My dad got caught with this , and changed the oil again immediately, but the same thing happened again so he then got in touch with the oil company, and was then told what was happening.

All this who-ha about oils when I have been using oils like the Caltex or Valvoline 20-50 for years and never had a problem associated with oil. People say red line is great because [ blah blah blah ] and it costs so much in NZ that its not worth using. We have heard the story of the guy who rode through south America and put in whatever oil he could get hold of [ any oil is better than none ]. If you have got deep pockets, and don mind wasting money on high priced oils, use them. As Andy chain said, "any thing with racing or motorcycle in its name is going to cost heeps more."
Honda's cars love 10-30 oil, but don't put it in a vehicle that likes 20-50 or it will slide past the rings.

Use your brains. Read the label. If it has an SE rating or better [ SD,SE, SF = BEST ]use it in your Commando. [ Don't use an economy oil as this is made thin for less resistance, unless it says you can use it in your Commando, which it probably wont ].

Dereck

Dereck and I old enough to remember about the time detergent oils came out and put into used sludged engines clots of sludge broke loose to clog oil passages so next they invented oil filters to catch passage clogging size stuff but not hardly any the wear causing particles. Its a total non issue to our Commandos as its sludge layers are detergent and slovent proof requiring physical removal that then builds back up pretty fast again if not keeping constant fresh oil or a bypass fine filter. I don't understand the reasoning behind non-detergent nil junk suspending oil on initial start ups as that as dirty particle sheding condition it will face unless a blow up. Diesel grade makes most sense to me then and afterwards.

Diesel has the highest "detergent" of all and good for cleaning diesels. It is not recommended fore petrol engines, and a diesel mechanic once told me he used diesel oil in his triumph for years [ because he had it ]. He used to wonder why it used oil though and didn't really think anything of it [ its an old triumph what the hell ] . One day he was discussing this with his oil rep, and the rep told him the bike was using oil because he was using diesel. He gave the mechanic friend a 5 l of "engine oil" and said you don't have to pay for this if it doesn't work. He ended up paying for it and buying a 20l pail of it.
So it just goes to show you, even mechanics can suffer from lack of information.
All the best for the new year. Dereck

ps the point I made earlier is that there was no excuse to use shit oils when Commandoes were new. The good oil wasn't expensive either, otherwise the service garages would not have bought it.

OK got it, leak prone BI engines may leak more with diesel level detergent oil cleaning the sealing sludge out, ugh.

Ta.

needing said:

Not my field either but as an consumer I'll add some further questions to keep the guesses coming.

You assume it is combustion blow-by but has anyone bothered to have their mucky black oil analysed? How much of the muck suspended in the car oil you use in your air-cooled motor bike engine is the 'burnt' oil itself?

I know it has been said before but "Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants."
Source: http://en.wikipedia.org/wiki/Surfactant

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I have had the oil from my bike analyzed a few times. When I was using conventional oil it was black due to oxidation.
It takes a long time to get black now that I use synthetic. Jim

Ta.

I got a 350 chevy engine out of my friends van that had a blown head gasket. When I took it apart, the inside of the oil pan looked like it had just come out of a hot tank or better yet a new pan. I asked him if he changed the oil every weekend. He said ,nope, never changed it. But, would add a can of Red Line whenever it was low. Amazing detergent package in that stuff I would say. Remember 20% of oil consists of additives.

OMG! Another oil thread full of hearsay, old wives tales, oil company reps, diesel mechanics, and Buddhist monks. Stop already; never start an oil thread on a forum. If you want to know anything check the oil company's website; it may actually have some facts.

Better yet, if you get the chance, talk "off the record" to one of the people who do oil analysis. They have seen the results and are not trying to defend their product. Jim

So am I hurting my old air cooled engines using diesel grade oil instead of cycle specific or automotive oils? Good luck finding department or auto store with C prefix grade oils.

The lighter weights of oil, 10W-30 and lighter, are now formulated to be "Energy Conserving".We don't want this ! These energy saving oils have additives that may cause clutch slipping and other problems. They are also short on additives that bike engines need like Phosphorous. These oils will have a "Starburst" on them and will say "Energy Conserving".Starburst Right now the heavier oils like 10W-40, 20W-50, 15W-40, and 15W-50 aren't labeled energy conserving and should be all right to use. If your bike needs one of the lighter oils, you could use a light diesel rated oil with a C designation like CG or CH. The diesel oils are not required to be "Energy Conserving". They have come out with a MA and MB designation, but I don't have a lot of info about them right now. Bottom line... A 10W-40 or 20W-50, automotive oil with no "Starburst" symbol, and no "Energy Conserving" label This Ones OK !, should be just fine. If you are really worried, get a motorcycle specific oil. However, they do cost a lot more.

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http://www.dansmc.com/4stroke_oil.htm

Well the Penrite 15w-50 Diesel oil i buy (20Ltr) for all my diesel vehicles indicate on the back that it is suitable for all modern engines..... and they show motor cycle as one of there so called "modern engines" pictures..... I use it in all my engines lawnmower, lancruiser, isuzu 4cyl 4wd, 865 triumph, 2 x Nortons, ducatti etc... I have used Penrite for more than 15 yrs with no oil related wear issues...
Though i dont race any engine but i change all at 5K no question ............. And if you think new Norton seals and rubbers are made of the same "rubber" as they were 40-50yrs ago.... :roll: :roll: :roll: :roll: :roll: :roll:

Plenty of the folks here use diesel oils in their old moderboikes.
It says on the tin its good in heavy duty petrol engines, and it is.....

Its always worth looking inside any engine pre 1960-ish though,
the sludge and layers of crud and carbon can be scary.