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Can anyone confirm this comment from thermodynamics book?

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In my thermodynamics textbook I noticed a comment about 2-stroke engines and wondered if anyone on here has more data/information about this.

"Major car companies have research programs underway on two-stroke engines which are expected to make a comeback in the future."

I know there are a lot of people on this forum who think 2 strokes will make a comeback, but I thought it was interesting to see it in a school textbook. This was the first time I have heard of modern car companies researching two strokes presently. Just thought I would see what people on here know/think. I did a quick google search and didn't see anything to support this statement.

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When was the book written? Not sure what's going on currently, but in the early/mid 90's companies were doing some major developement with Orbital's direct injection 2 stroke systems. Ford had a lot of Festiva's with Orbital systems in them, and even had this "2010" concept in 1993.

(click first article in link)

http://www.google.com/search?tbm=bks&tbo=1&q=ford+orbital+2+stroke&btnG=

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That is an interesting article about the Ford. Very cool.

This version of the book was released in 2011, but it is the seventh edition. The book companies tend to change a few pictures and problems then call it a new edition and charge more for it. So it wouldn't surprise me if this was outdated information that keeps getting copied into newer editions.

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The most fuel efficient engines in terms of fuel consumption per horsepower hour are 2-strokes. These engines also have very long strokes, a valve, and rely heavily on turbocharging for waste heat recovery. But, their efficiency comes from a massively long stroke, low operating speed, and extremely high peak firing pressures. These are all things that don't scale down well.

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Big diesels. Ship board engines and rail prime movers. Even with the inevitable loss of energy associated with the conversion from diesel to electric power, freight trains roll up about 436 MPG per ton. That of course is true and interesting, but it's only remotely related to engines under eight liters, never mind two. As you say, it just doesn't scale down.

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As far as it being in your thermo book, i dont see why it would mention 2 stroke engines other than for referencing its different style of heat/energy exchange compared to other motors. I believe (if i remember correctly) that my thermo book did this with the wankle engine.

Now as far as the two stroke making a comeback, i would have to say that one of the biggest reasons its ability to create considerably less pollution from the exhaust. I know that seems odd because two strokes make so much smoke, but if you can use direct injection with a 2T engine, exhaust gasses are really really low. There have been some companies, and even some individuals take a shot at it.

I believe there were rumors of KTM coming out with a direct injection 2T a couple of years ago.

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