Why hasn't the internal combustion engine been replaced?

[DougC]

• • • Electric motors are better in theory than gasoline engines. Electric motors can operate from zero RPM and many types can operate in both directions of rotation. There have been “demonstrator” cars built that used a motor mounted inside the hub of each wheel, eliminating the need for any sort of mechanical transmission or driveline, and in that system it would even be possible to use the electric motor for either active or regenerative braking, eliminating the need for conventional brakes as well. The practical problem with electric motors is that nobody has yet found a really good way to store lots and lots of electricity without resorting to using a conventional combustion engine as a generator.
• As to why we still use piston engines for IC, it’s because compared to what’s available, piston engines have a fairly-wide RPM range that they can operate at, and their powerband can be spread over a fairly-wide part of that range, as well as easily be engineered to peak at some specific RPM if need be.
  …Turbine engines can be more efficient, but because their compression and exhaust stages are “unsealed”, only at one speed–their efficiency basically increases with RPM, so they are operated at very-near their top RPM limit, up around 95% is usually the duty RPM rating–and at lower speeds their fuel efficiency drops WAY off. They are essentially considered to be single-speed engines.
  …Rotary engines (as used in the RX-series of cars by Mazda motor company) are more efficient than piston engines by some measures but are also considerably more expensive to produce, and they have a few mechanical weaknesses unique to them. If rotary engines were better on all criteria, Mazda would be using them for all their cars.
  ~

[Bryan_Ekers]

What’s fire done for us lately? Unholy pagan stuff, it is.

[R.P.McMurphy]

@DougC

• • • Electric motors are better in theory than gasoline engines. . .
• As to why we still use piston . . .
  …Turbine engines . . .
  …Rotary engines . . .

1.) Which is the reason for all of the work on the hybrid technology.

2.) Until we come up with something better.

3.) Chrysler tried to develop a turbine car. One huge problem was the amount of heat they give off. On a side note, when the military developed a tank with a turbine engine the heat signature made it a sitting duck for a technologically advanced enemy.

4.) Correct me if I’m wrong but I thought that a major limitation of the rotary was fuel economy. Performance was good but they sucked a lot of gas. Also the combustion chamber seals wore out which is a very expensive maintenance and repair consideration.

[Hoodoo_Ulove]

@Spartydog

4.) Correct me if I’m wrong but I thought that a major limitation of the rotary was fuel economy.

Right. The combution chamber has a very high surface to volume ratio, thus greater heat losses. But don’t say “was”; Mazda is selling them again.

[Tuckerfan]

@Spartydog

3.) Chrysler tried to develop a turbine car. One huge problem was the amount of heat they give off. On a side note, when the military developed a tank with a turbine engine the heat signature made it a sitting duck for a technologically advanced enemy.

Which Chrysler turbine car? The 1963 model? Or the 1981 model which was scheduled to go into production until the Feds ordered the program killed.

When the Corporation was in such dire straights, back in 1979, we all know what happened, or do we?

Chrysler got some loans from the US Government…that much is certain. That Chrysler (as a condition of those loans) had to sell off Chrysler Defense and the M1 turbine-powered tank program is somewhat lesser known, but still public knowledge.

What is known only to a priveleged few is that the government killed a dream of a lifetime for a group of 70 people at the Chrysler “skunkworks” in Highland Park.

Believe it or not, Chrysler was days away from making a production decision (one which Iacocca favored) on a rather unique vehicle…

1981 Chrysler New Yorker Turbine car (M-body)… the car was ready to be tooled according to the head of the program, Mr. George Scheckter, whom I met when I got to see and touch the 1963 Turbine Car again in 1989. There was no more design work to be accomplished, just tool and start production.

The Turbine Engine was a fifth generation (not a 3rd generation like the 1963 car) engine capable of 22mpg in the EPA test cycles. To really make this sink in, one of the prototypes is still in existence (at least it was in 1989), stored in the same building as the 1963 car, its tooling and all the remaining spare parts (enough to build 3 more of the '63 cars).

Your government thought it was too much of a risk and ordered the car cancelled as “too risky, from an economic standpoint.” Just imagine what COULD have happened!

(emphasis in the original)

4.) Correct me if I’m wrong but I thought that a major limitation of the rotary was fuel economy. Performance was good but they sucked a lot of gas. Also the combustion chamber seals wore out which is a very expensive maintenance and repair consideration.

I think you’re right about the fuel economy standpoint, but I also believe that Wankels tend to have higher emission levels as well.

[robby]

@Raguleader

I remember having it pointed out to me in a History of US Seapower class that all ships have been essentially using the same type of engine since the early 1800s. Whether it uses a paddlewheel or a screw, pistons or turbines, coal, diesel, jet fuel, or Uranium, practically all ships use steam engines. The only thing that changes are how you MAKE the steam, and what you DO with the steam (including some novel concepts, such as using the steam to physically toss airplanes off the end of the ship with a catapult)

There are indeed ships being used today still powered by steam. The nuclear submarine I was on had a steam plant. I’m sure there are still some fossil-fueled steam plants out there as well.

However, most new non-nuclear ships have nothing to do with steam. These include the common diesel power plants, and the fancy gas-turbine ships.