Synthetic lubricants VS. Petroleum

[Duke W.]

Oiless engine demo

Yeah, I remember seeing a similar demo at the Pomona swap meet years ago. It was an old Chrysler slant six with no oil pan, just barely turning over at maybe 400 RPM. When I was a kid I remember seeing a demo at the Seattle Auto Show. This guy had a rotating cup with three big ball bearings. He poured in some motor oil then brought down this cone with a lever to load up the bearings. Within a few seconds the cup started smoking and the bearings seized together. Then he ran the test with a miracle additive, and, of course, they just kept turning now matter how long and hard he pulled on the lever. Years later I asked one of my professors who taught a bearing design and lubrication class about this demo. He knew the drill. These formulations have a heavy dose of EP (extreme pressure) additives that will provide good low speed "boundary lubrication", but in an automotive engine, most lubrication is between high relative velocity surfaces and a hydrodymanic film is developed which keeps the surfaces apart. It's like hydroplaning on the freeway in the rain with bald tires. Most guys think of oil pressure in terms of feed pressure from the gallery, but the pressure developed inside the bearing is several THOUSAND pounds per square inch. One exception is the rings, which come to a complete stop twice per revolution, and they are loaded by gas pressure every other trip to the top. This is why bores taper, but modern oils have sufficient EP additives to keep taper wear reasonable, and nobody has ever proved that more EP additives will reduce taper wear during normal use. The old slant six is probably still idling, because at a 400 RPM idle with no load, the EP additives provide enough boundary lubrication to keep the bearings from seizing.

Regarding the Porsches, they have a 12 quart sump and an oil change interval of 15,000 miles or one year.

Duke

[Michael W.]

Re: Oiless engine demo

You're not inferring that this was the dreaded SNAKE OIL again are you? Heavens!


Quebec NCRS Chapter

[Duke W.]

A slick story

I read Flying magazine on occasion. It's the industry bible for genaral aviation guys. Toward the back they have a section that summarizes recently released accident investigation reports. One in particular, about ten years ago, caught my attention. It involved an in flight engine seizure. Subsequent tear down and inspection of the engine revealed that an oil gallery had been blocked by "teflon" where two gun drillings came together to form a 90 degree direction change. These "teflon" additives are long stringy molecules and are actually dissolved solids. Apparently, the centrifugal force of making the corner had flung the teflon to the dead spot and it built up, finally blocking the gallery and starving the bearings. A few year ago I asked an A&P mechanic if there were ever any bulletins about Slick 5O or any other "teflon" additives, and he said he was not aware of any. As far as additives are concerned I follow the advice of the General. I don't ever recall reading a GM owner's manual that did not specifically recommend AGAINST using any supplemental oil additives. Their advice has always been to use the proper API spec oil and change it at the recommended mileage or time interval, WHICHEVER COMES FIRST!

[Doug Flaten]

Re: Good Information Duke

I like what I am hearing. The motorcycle industry is thick with snake oil sales, many of which are loaded up with anti wear additives. I have held the opinion that extreme amounts of anti-wear additives were not necessary. They claim those additives bond with the parts and provide additional protection especially in hotter air cooled engines. It seems to me that if this is what is supposed to save your engine, then the lubricating film of your base stock has broken down and you aren't going to last long anyway. Besides, these additives end up depositing more carbon in your cylinder which leads to pre-ignition. As your other post points out, aviation lubes have very little additives due to the ash content. I often wonder why those lubes are not used for cycles and autos. I can only surmise that do to FAA requirements, airplanes get more maintenance and inspection and the average auto driver is relatively neglectful of scheduled maintenance.

[motorman]

Re: I'll give it a shot

GM has put a engine oil life test system in the C-5 corvettes and it checks things like number of starts, oil temp. and from this it tell how much oil life is left. you can go up to 10,000 mile under some conditions before it tells you to change the oil. GM said there is too much good oil dumped every year and if the oil supply runs out they are out of business.

[Doug Flaten]

Re: I'll give it a shot

GM will be in business for a while. Unocal was the last to shut down their oil shale project in the late 80's or 90's after the gov't subsidies ceased. It is not cheap oil put they can mine shale, crush and cook it and extract and synthesize a crude. The project almost got to be a break even proposition. Years down the road when prices are much higher and assuming "mining" is not completely outlawed, it may be viable again.

[motorman]

Re: I'll give it a shot

we even did some shale oil work when i was at westinghouse.trying to come up with ways to extract oil from shale.

[Bill Braun]

Re: A slick story

Duke,

Just as a general question: Here is Switzerland, used motor oil is treated almost like toxic waste. I know it is collected by various recycling companies. Is it possible to "recycle" oil? Can one filter the impurities and "recondition" it to yield a usable lubricant? Just wondering... Bill Braun

[Duke W.]

Used motor oil uses

Used motor oil is also considered "hazardous material" over here and most areas of the US have recycling programs for both commercial shops and the DIY crowd. When I was a kid working in a gas station we sold "re-refined oil", which was some kind of processed used oil, but I don't know anything about the process. At two-bits a quart it was popular with out customers who drove beaters.

My understanding is that the used motor oil collected in Southern California is processed by filtering and then added (about five percent) to bunker oil that is used the by the huge compresssion ignition (diesel) engines that power modern ships.

Duke