Engine without oil?

Yeah, why can’t autos use turbine engines?

Check this out:


The Wikipedia article touches on the drawbacks. In short there’s no advantage to a turbine and a few disadvantages (loud, nitrogen oxide output, poor acceleration unless you keep the damn thing spinning all the time, etc.)

None of those drawbacks apply to the Capstone turbine when used in a hybrid electric vecle. The Chrysler turbine car tried to integrate it into a conventional transmission, which created the acceleration problems. Emissions from the Capstone turbine meet California standards, the toughest in the nation.

Turbine engines were predicted to be displace piston engines in ‘The Future’.

Sure, because a hybrid had an IC engine for decent acceleration. The OP is asking about engines without oil and the hybrid doesn’t get rid of that need for oil as it still has the IC.

Capstone hybrids have no internal combustion engine.

Huh, just googled “Capstone hybrids” - very interesting, kind of like a modern locomotive setup.

Indeed. My high school physics teacher predicted that it wouldn’t be long before either the electric car or the turbine engine version would replace 90% of internal combustion, piston engines. “By time your kids are driving…”

He thought it would take 20 years, tops. Imagine his surprise if he had lived to find out that, after 55 years, it still hasn’t happened and isn’t likely to happen soon.

But the turbine has an internal combustion chamber…not sure what the difference is between that and a cylinder.

Oil is both a lube and a heat removal method. Having less oil in the motor means changing it more, and also less effective heat removal, so that in itself not that helpful. Some of the larger issues is oil contamination and dilution by blowby (products of combustion getting into the oil), that can be reduced, and that can increase oil life.

I remember the discussions in the 60s. Was a turbine engine an Internal combustion engine or external. One argument that combustion (turning chemical energy into heat energy) occurred outside the engine (the part that converts heat energy to mechanical energy). Therefore an external engine. On a true IC engine the combustion happens in the same place that heat energy is converted to mechanical energy. The other argument was because the combustion happened between the compressor and the turbine, and the turbine was linked to the compressor it was all one engine therefore an IC engine.

The Future turned out to be impractical, so we have to make do with The Past with cosmetic improvements.

Don’t some types of engines use the fuel as lubricant, thus not requiring a separate “oil”?

Do electric cars still need oil?

Oil does so many jobs in most typical internal combustion engines, that it cannot be eliminated or easily reduced.

  1. Oil acts as a lubricant to reduce friction, and thus prevent excessive localized heat. Between bearings, bushings, gears, chain links, lobed rotors, sliding followers, sliding pistons and rings, and several other actions that create a lot of friction in an engine, oil keeps the friction down and, consequently, less heat is built up.

  2. Oil acts as a lubricant to reduce friction, and thus prevent excessive wear of moving components. Most of the moving parts in a properly lubricated and maintained engine will last for many tens or hundreds of thousands of miles due to low wear aided by oil lubrication, but might not make it around the block in a dry engine.

  3. Oil acts as an overall coolant. Though the water-based cooling system removes most of the excess heat produced in an engine, oil splash, drainage, coverage and return count for a significant amount also.

  4. Oil acts as a localized coolant. Some parts in an engine cannot be cooled by the standard coolant system, and general oil windage isn’t sufficient. A good example is the bottom of the pistons. These parts get quite hot mostly from transference of combustion chamber heat, and can fatigue or fail under certain conditions. Many engines are set up so that a squirt or stream of oil is directed right at the bottom of the piston, which provides extra oil cooling and those critical parts.

  5. Oil acts as a hydraulic fluid. Though many newer engines do not have the same hydraulically pumped cam followers and valve lifters of older engines, there are many engines that have components that adjust and operate using engine oil as a hydraulic fluid.

  6. Oil washes and removes contamination from ordinary use of an engine. Small particles of metal from the many moving parts and carbon buildup from the combustion chamber that bypass the rings - these are all removed from the working areas and drain to the crankcase, where the oiling system filters them out of the oil before sending it back on its way again. If not for oil filtration, these parts would compromise the chemical quality of the oil and introduce abrasive and corrosive elements into the engine in an ongoing basis.

A lot of changes have been made in standard automobile combustion engines in the last 20 years or so that have reduced the requirement for oil in some areas of operation, and many other improvements are possible, but not yet implemented due to cost or further development needed, but the basic engine design has not been replaces because it is still to simple and efficient of a design, even in modern times.

Gas turbines are clearly internal combustion engines; the only difference being that it’s not entirely closed at some point in the cycle. The working fluid is the combustion by-products, not something heated by combustion somewhere else before it’s within the engine itself.

A steam turbine is an external combustion engine, since the combustion is used to heat up the working fluid in a boiler separate from the turbine, but the fuel or exhaust isn’t actually used to generate power directly. Same goes for steam locomotives- the coal or oil heats up the steam which goes through the cylinders.

I think you need to reconsider, by your definition a campfire is internal combustion.

The reason I asked this is that oil is the weakest link in engines. Engine wear due to insufficient or dirty oil causes engines eventually to die. How many people neglect their oil and end up with problems? If engines could be designed so that they didn’t wear out in this way it would be great.

I understand what you are saying, but lubercation is also a strength that allows such things to exist. There is a show on Modern Marvels that highlights ‘lubrication’ and all the benefits it gives. It is a reason that the modern world exists. I would suggest trying to find that episode, I think it is on the discovery channel, and may be netflixable.

It is not so much as a design flaw and neglected maintenance that would cause such a failure. But yes excessive oil consumption could cause a large part in this.

If you have ever seen an old movie showing an aeroplane losing oil pressure in the piston engines, you know that this is not a trivial matter. Though nothing is perfect and things do wear out, I think eliminating oil from engines would be wonderful if it could be achieved.


Not to mention maintenance mistakes…


I’m not disputing that, and engine oil failure was the reason why the marines let Gus Griffon’s capsule sink, though it does seem manageable, and there does seems ways that can prolong it’s life that have not been implemented.