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  1. JSteve2

    Lets take a step from reality. Engine theory and efficiency

    You can only achieve the efficiencies you seem to be suggesting at extremely high combustion temperatures - truly extreme to take the 42% or so theoretical maximum on current combustion engines up to 80%+. Because of the very efficient fuel cell competitor for your technology, you will have to...
  2. JSteve2

    MPG loss with 10% ethanol---

    Ethanol is more volatile than standard gasoline, and in many areas is allowed to test at a higher vapor pressure. I think those must be places where the allowance is not in place. If you can get your gasoline with ethanol to test within the standard, it can be used in those places. This map is...
  3. JSteve2

    MPG loss with 10% ethanol---

    The ethanol could also be causing something in the system to change, like a temperature somewhere in the system, that causes a different fuel map to be utilized.
  4. JSteve2

    diesel vs gas

    BigClive, I don't think there's anything technically incorrect with what you are saying. Here is why I wouldn't state things that way - first if I make an engine with high CR relative to low CR, and run the thing without fueling it, the exhaust temperature of the high CR is higher than the low...
  5. JSteve2

    diesel vs gas

    Greg, I agree. I was emphasizing that a high compression ratio is not a synonym for, and does not imply, a manipulated expansion ratio.
  6. JSteve2

    diesel vs gas

    @PEW - I bet starting that thing was a challenge.
  7. JSteve2

    diesel vs gas

    BigClive, I'm not sure what you mean by that, but without modification that is a misleading way to think about it. The single greatest effect is that you have a more efficient heat engine from a greater temperature difference enabled by the high compression ratio. Since one side of this is...
  8. JSteve2

    diesel vs gas

    CI runs cooler because more of the energy is going to work rather than heat, and because there is so much inert material to absorb the heat energy. At load, they can run very high exhaust temperatures. Expansion ratio and nonhomogeneous fuel air mixtures are not the correct way to view this...
  9. JSteve2

    diesel vs gas

    Some pretty typical numbers - a commercial diesel engine will run (at some loaded value) around twice the compression, and per unit volume maybe 4 times the moles of cylinder gas, and maybe 2.5 to 3 times the mass of fuel. The peak combustion pressures and temperatures are both much higher than...
  10. JSteve2

    % Engine Load vs. % Power

    The correct answer to your question, within limits, is yes. Torque (if that is what you mean by "load") multiplied by engine speed is proportional to the engine power output. If, by load, you mean the torque at the engine tailshaft, then cutting load in half at the same speed cuts the power...
  11. JSteve2

    Electric Handbrake / Emergency brake - Why?

    Rod - no offense taken. I may know how cars work, but I don't get involved in the maintenance. I even (gasp) get my oil changed at Jiffy Lube. Not that they are better than me (although maybe) but at least they will buy me a new engine if they screw it up. I think many consumers, the folks car...
  12. JSteve2

    Electric Handbrake / Emergency brake - Why?

    A few thoughts: Every car I've owned before the year 2000 had a failed brake. Usually, a previous owner drove with it engaged. It would hold a parked car generally, but was worthless as an auxiliary braking device. Granted, we're talking about a long line of old, crappy cars. @Mike - you are a...
  13. JSteve2

    Electric Handbrake / Emergency brake - Why?

    I understand that a number of skilled drivers have opinions on the many ways they can use the hand brake to enhance their driving experience. However, given that these situations are few, even skilled drivers rarely think of them at the needed moment of duress. Hand brakes are often failed...
  14. JSteve2

    Diesel over gasoline engines

    Warpspeed, There is more energy per unit volume in diesel, but less energy per unit mass. That sort of wipes out the airplane theory. And the difference is modest (maybe 10% net specific energy per volume). The bulk of the fuel efficiency difference really is the combustion mechanism. See my...
  15. JSteve2

    Water electrolysis HHO conversion. Thermodynamics

    If you make gas out of water and then burn it, if water is the product of the burning, then you must lose useful energy in that cycle. If the product is something having a lower energy level than water, then theoretically you could have some net energy there to recover. Unfortunately, water is a...
  16. JSteve2

    Diesel over gasoline engines

    I have a few additions or modification to what has already been suggested. One, it is more efficient in the global oil cycle to have a significant fraction of the fuel oil go to each diesel and gasoline due to the natural fractions of hydrocarbons in crude oil. Thus, cost competition between...
  17. JSteve2

    Straight Line Reciprocating Engine...

    @dicer: I think the basic design of the IC engine will, at some point, be significantly improved upon. It will probably occur because something that is viewed as a constraint today will no longer be a constraint someday. Materials, computerization, or some other breakthrough will change...
  18. JSteve2

    Ceramic Adiabatic Engine

    jmc41, the first two lines of your last post are just not correct. I'm trying to understand if you mean something else and that's just not stated correctly, since much of the rest of your post seems reasonable.
  19. JSteve2

    Fossil Fuel Stabiliser

    This is utter garbage. If one of these things worked, the inventor would sell it to one of the oil companies and it would be on the refinery outlet or the gas pump.
  20. JSteve2

    Dyno correction factor vs air density

    black2003cobra, Good info - thank you. Is it only good for a narrow range because that's where the assumptions are good?

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