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Very roughly, Motor car engine oil viscosities are half the quoted aviation grade. So, a car 40 is equal to an aviation 80.When I frequented the local flying club many years ago, I heard technicians say that they used "100 viscosity" lubricating oil for the piston engines of small touring planes. At the time, common car engine oils had grades of 10W/40 or so. I've always wondered why airplanes needed such high viscosity, guessing it was the same for WWII era.
Very roughly, Motor car engine oil viscosities are half the quoted aviation grade. So, a car 40 is equal to an aviation 80.
Eng
Frankly, so far I'm a bit confusedSo, how do you think using your example of 10W/40 in a mid life aero-engine designed for straight 80 would effect?
Frankly, so far I'm a bit confused. Mainly because I miss a criterion for aeronautical oil. On Wikipedia, I read that there's a standard for automotive, the SAE J300. According to it the 10W/40 equals a centipoise viscosity of 7000 at -25°C and between 12.5 and 16.3 centistokes at 100°C. But what about aviation piston engine oils?
How drunk is it?.. It is another world of science, like what compressive load can the molecular bonds of an oil withstand?
Yup, I started to have thoughts like that. I concluded that producing oils needs the oil companies and engine designers to know a lot of clever stuff and left it at that.How drunk is it?
That is just LOL funny. Imagine the time and money involved in developing a sintered bearing that does just what you want it to as regards lubricant flow and load bearing? Then someone has an idea to make things better.When I was at OC-ALC we had a problem with sintered bearing (kind of a porous sleeve made from compressing powdered metal) was not doing the job. Turned out that the manufacturer had coated it with an anti-corrosion oil that was preventing the oil that was supposed to impregnate it from getting down into the nooks and crannies. The answer was to boil the things in the proper oil for a while.
As I said a couple of posts up, there is a lot of very clever stuff involved, some of it being the opposite of "common sense" which isnt sense or common.Eastman Kodak used sintered bronze bearings with an attached metal clip which held a piece of one inch square by 1/8 inch thick felt in contact with the bearing. Six month maintenance on the equipment meant a couple drops of 30W oil on the felt. These bearings seemed to last forever if kept lubricated, as the heat of the shaft running in them pulled the oil to the shaft surface. The only problems happened if seldom lubed or a new guy thought he just discovered WD-40 as a "better" lubricant. Two weeks after the new guy finished, every bronze bushing need to be replaced as the alcohol in the WD-40 reversed the oil flow and drove out the oil impregnated within the bronze. Newer equipment by the 1970s did away with felt as it appears the bearing composition changed and now direct oil drops were applied at the shaft/bearing surface. Bearings were now often changed due to wear.
As I said a couple of posts up, there is a lot of very clever stuff involved, some of it being the opposite of "common sense" which isnt sense or common.
WD-40 was not designed as a lubricant but was created for Water Displacement on the Atlas ICBM. You could not paint the tank on the Atlas because it was made of thin stainless steel and since it was a balloon, tended to flex and pop the paint off, assuming the cryogenic temperatures on the LOX tank even left any. Our converted Atlas ICBM space boosters typically had all the paint gone off the LOX tank, leading to a truncated national star insignia which was painted along the LOX and RP-1 tank interface. The original producer was the Rocket Chemical Company of San Diego. As a water displacing substance, WD-40 contains DMSO, a cleaning chemical, and so will clean out other lubricants or other substances already there, including water.thought he just discovered WD-40 as a "better" lubricant
Hi Greybeard, There are many different standards and specifications for lubricants, but possibly the SAE J1966 and J 1899 might cover your interest. As I said, many specific standards are only available to purchase, but you can usually find product specifications with details online. The standards are produced by many institutions and government bodies. They include SAE, ASTM, JASO, ACEA and API to name but a few. Military standards are held by many different countries.Sorry guys, I think there is a gigantic misunderstanding: I see we slipped from a simple question of mine to rocket science. Probably my fault since English is not my native language.
So far I believe first answer by Engineman is clear enough for me: unit of measure of aviation oil viscosity is about half of automotive one, so the values are twice. In addition, I was just wondering which is the standard for viscosity of aeronautical oils, like the SAE J300 is for automotive. Nothing more. Thanks anyway to all who kindly replied.
The DMSO is why people used it for a topical arthritis pain remedy.WD-40 was not designed as a lubricant but was created for Water Displacement on the Atlas ICBM. You could not paint the tank on the Atlas because it was made of thin stainless steel and since it was a balloon, tended to flex and pop the paint off, assuming the cryogenic temperatures on the LOX tank even left any. Our converted Atlas ICBM space boosters typically had all the paint gone off the LOX tank, leading to a truncated national star insignia which was painted along the LOX and RP-1 tank interface. The original producer was the Rocket Chemical Company of San Diego. As a water displacing substance, WD-40 contains DMSO, a cleaning chemical, and so will clean out other lubricants or other substances already there, including water.