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#61
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Bill,
the most efficient diesel engines (large, like container ship large) are only thirty-something % effecient. Noise, jacket and exhaust temperature increase make up the rest of the power otherwise put in. Small engines, like those even in your american supersize cars, are pitifully inefficient in comparison to a ship size diesel. Low 20s % is pretty good for new technology. But hey! Someone wants to re-power a self-launcher with hydrogen, LI batteries (more than 2 birds needed!) nuke - I dont care, bring it on! The best place for a rotax is on a lawnmower Bagger (diving, rolling for cover) :-) |
#62
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Tow cars and trailers
Actually, the enormous Sulzer 2-stroke diesels used in container ships get
more than 50% thermal efficiency and produce more than100,000 HP at ~100 RPM. In general, the bigger they are, the higher the efficiency. See: http://people.bath.ac.uk/ccsshb/12cyl/ The much maligned American V8 actually can top 40% effeciency if operated carefully. That number results from recovery of reject heat energy inherent in the V8 concept. As they are normally operated, they get more like 25% thermal effeciency, however. If I run my 5.2L V8 at 1500RPM (45mph) on a straight and level road it gets 37 MPG. As for electrics, one of the really far out ideas under vigorous research right now is "Beta Voltaics". It is a device that captures the energy of beta electrons from the radioactive decay of tritium much like a solar cell captures energy from photons. Combine this with Lithium cells and you have a "self charging" battery. Bill Daniels "bagmaker" wrote in message ... Bill, the most efficient diesel engines (large, like container ship large) are only thirty-something % effecient. Noise, jacket and exhaust temperature increase make up the rest of the power otherwise put in. Small engines, like those even in your american supersize cars, are pitifully inefficient in comparison to a ship size diesel. Low 20s % is pretty good for new technology. But hey! Someone wants to re-power a self-launcher with hydrogen, LI batteries (more than 2 birds needed!) nuke - I dont care, bring it on! The best place for a rotax is on a lawnmower Bagger (diving, rolling for cover) :-) -- bagmaker |
#63
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OT: Tow cars and trailers
Can you imagine the change that would occur in our atmosphere if
millions of vehicles around the world would be burning Hydrogen and producing water vapor as a by-product? This vapor will be condensed at some point and most likely just when you want to fly. Over-developing sky and increase precipitation. The clouds would reflect the suns energy and we would enter a new ice age. Maybe it is an antidote to global warming. |
#64
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OT: Tow cars and trailers
On May 22, 1:37 am, "Bill Daniels" bildan@comcast-dot-net wrote:
Hmm... I'd suggest reading this article by no less than EV Weekly: Fuel Cells - a Reality Checkhttp://www.evworld.com/article.cfm?storyid=730 That article is three years old - as I said, fuel cells are getting the funding because of their *potential*. Three years later usable fuel cars exist: http://www.autobloggreen.com/2007/05...-with-hydrogen OK, they're $35m each, but it shows what is feasible :-). In the last few days, one of the national labs, Los Alamos I think, reported doubling the energy density of lithium ion batteries while virtually eliminating thermal runaway. Yes, the manganese electrode from Argonne. Quite an interesting development, not least as the researchers didn't expect that level of success and don't know how come it worked! Currently has severe issues with the manganese being consumed and excessive oxygen production (lithium+oxygen=bang). Still, could lead to some interesting developments. But laptop fuel cell batteries already have 20 hour endurances, so even a doubling of capacity wouldn't bring li batteries close to the same level of performance. Re your efficient V8 - is your engine one which shuts down a bank at low load? I believe quite a few US V8s do that nowadays, so you were actually getting 37mpg from a 2.7l I4 :-). Also I can't say I fancy driving at 45mph everywhere - I measured my European petrol car at 39mpg last year after a 200 mile drive at 90mph. Dan |
#65
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OT: Tow cars and trailers
Re your efficient V8 - is your engine one which shuts down a bank at low load? I believe quite a few US V8s do that nowadays, so you were actually getting 37mpg from a 2.7l I4 :-). Also I can't say I fancy driving at 45mph everywhere - I measured my European petrol car at 39mpg last year after a 200 mile drive at 90mph. Dan Nothing that fancy. It runs on 8 all the time. My point that the roughly round shape of a V8 has minimum surface area for heat leakage and has some low tech but effective heat redistribution passages that increase efficiency. Henry Ford figgured that out back in the 1930's. The biggest problem with a V8 isn't the number of cylinders which have the advantage of increasing the total piston area and decreasing pumping losses. The real problem is internal friction from all those moving parts. A somewhat plausable comparison is a 4 cylinder Lycoming 360 Cu In airplane engine which can be easilly turned over by hand - something that is impossible with my 318 Cu In V8. There are low friction thin films that can be vapor deposited onto engine parts. Motorcycle racers use them to get 8 - 10% more efficiency. I'd like to see what that would do for the venerable V8. Combining our two ideas it seems that what you get with a more fuel efficient car is the ability to drive it faster while using about the same amount of fuel. I can get good economy by just slowing down while retaining the capability of towing a heavy trailer. Bill Daniels |
#66
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OT: Tow cars and trailers
If this appears twice, it's cos I'm having trouble posting (anyone
else?) On May 22, 1:37 am, "Bill Daniels" bildan@comcast-dot-net wrote: Hmm... I'd suggest reading this article by no less than EV Weekly: Fuel Cells - a Reality Checkhttp://www.evworld.com/article.cfm?storyid=730 That article is four years old - as I said fuel cell's promise is in the potential, and now there are (proper, not lightweight specials) cars capable of 300 miles on a single fill of hydrogen: http://www.autobloggreen.com/2007/05...-with-hydrogen In the last few days, one of the national labs, Los Alamos I think, reported doubling the energy density of lithium ion batteries while virtually eliminating thermal runaway. T'was Argonne using manganese electrodes. It's interesting as the researchers neither expected the results nor can explain them! Still plenty of issues - limited life cycles and excessive production of oxygen (lithium+oxygen+heat=BANG). Even with a doubling of capacity li batteries can't match fuel cells though - Panasonic has a fuel cell laptop battery with a 20 hour endurance. Much more expensive to produce of course but demonstrates the much greater performance possible with FCs. Re your efficient V8 - is yours one of those new ones which shuts down a bank at light loads? If so you got 37mpg from a 2.7l I4, not a 5.2l V8 :-). Mind you I don't fancy driving everywhere at 45mph - I measured 39mpg from my Euro petrol over a 200 mile 90mph drive last year. Dan |
#67
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Tow cars and trailers
I absolutely agree and I admire those European diesels. Unfortunately few
of them are available in the US. Until very recently the only passenger car available with a diesel was the VW Passat. Id love to trade my V8 for a diesel. Bill Daniels "Asbjorn Hojmark" wrote in message t... On Tue, 22 May 2007 09:17:04 -0600, "Bill Daniels" bildan@comcast-dot-net wrote: If I run my 5.2L V8 at 1500RPM (45mph) on a straight and level road it gets 37 MPG. Many European cars rutinely do 35-45 MPG *on average* and close to 50 MPG on a straight and level road. That's running on diesel, but with only e.g. 150 g/km CO2 emission. Your 5,2L is likely more than double. -A -- http://www.hojmark.org/soaring.html |
#68
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Tow cars and trailers
On May 19, 2:06 pm, Stewart Kissel
wrote: Your diatribe reminded me of a line from a long forgotten movie from the '70's called 'Rancho Deluxe'. I clipped the quote below from a review of that movie. Oversized SUV's rate right up there with Coca-Cola and MacDonalds as proof what clever marketing combined with US tastes can produce And I happen to drive a F150-great tow vehicle, lousy gas mileage. 'I've seen more of this state's poor cowboys, miners, railroaders and Indians go broke buyin' pickup trucks. The poor people of this state are dope fiends for pickup trucks. As soon's they get ten cents ahead they trade in on a new pickup truck. The families, homesteads, schools, hospitals and happiness of Montana have been sold down the river to buy pickup trucks!... And there's a sickness here worse than alcohol and dope. It is the pickup truck death! And there's no cure in sight.' Conversely, I cannot understand why people would want to drive something the size of a Tahoe, or Suburban or whatever on a daily basis. Most of these are simply marketing exercises to improve profits. Cheap, relatively unsophisticated light truck design. Add massive body (to cart sprung bendy chassis) - way up high so the CG gets even worse, and market it as a lifestyle. Give it slab sides to look macho - Very good for profits, even if the roll over accident rate soars...- Hide quoted text - - Show quoted text - I own a 2001 VW Eurovan camper. It has the Passat engine (6 cyl, 24 valve) and 16 " wheels. It tows like a dream and gets near 20 mpg. They quit importing to the US in 2003 and now are in high demand. I paid a little over 30k for mine. A year later for the exact same vehicle the price went to 40k and now people are paying up to 50k for a low mileage version of the 2001-2003 models. It also doubles as a good around town vehicle (unlike most RVs) It seats six and drives and parks like any midsize car. George |
#69
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Tow cars and trailers
bikensoar wrote:
I own a 2001 VW Eurovan camper. It has the Passat engine (6 cyl, 24 valve) and 16 " wheels. It tows like a dream and gets near 20 mpg. They quit importing to the US in 2003 and now are in high demand. I paid a little over 30k for mine. A year later for the exact same vehicle the price went to 40k and now people are paying up to 50k for a low mileage version of the 2001-2003 models. I've had a '97 Eurovan Camper for 10 years and 100,000 miles. It still gets over 20 MPG on the highway, tows beautifully, and had no trouble pulling our Duo over the steepest mountain passes in California, Nevada, and Utah... Marc |
#70
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Tow cars and trailers
Don't forget that in the US you are shortchanged whenever you
buy a gallon of fuel: 1 gallon = 4.54 litres 1 US gallon = 3.78 litres this can make US prices and mpg ratings appear artifically low. Similarly 1 pint = 16/20 fluid ounces. In the US you are also shortchanged in weight: their "short ton" = 2000lb whereas the "long ton" is 2240lbs. Similarly 1cwt = 100/112lbs. The next lessons will discuss the difference between the rod/pole/ perch, plus the relationship between the acre, the length of a cricket pitch, a (statute) mile and the amount of land that can be ploughed by two horses in one day. On May 22, 9:13 pm, Asbjorn Hojmark wrote: On Tue, 22 May 2007 09:17:04 -0600, "Bill Daniels" bildan@comcast-dot-net wrote: If I run my 5.2L V8 at 1500RPM (45mph) on a straight and level road it gets 37 MPG. Many European cars rutinely do 35-45 MPG *on average* and close to 50 MPG on a straight and level road. That's running on diesel, but with only e.g. 150 g/km CO2 emission. Your 5,2L is likely more than double. -A --http://www.hojmark.org/soaring.html |
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