On Mon, 13 Feb 2006 11:57:59 +0100, Frithiof Andreas Jensen wrote:

...funding available).

Ladies and gentlefolk, I believe we have a winner!

Cheers!
Rich
--
"We have met the enemy and he is us." - Pogo Possum

On Mon, 13 Feb 2006 08:54:55 -0700, Jim Thompson wrote:
On 13 Feb 2006 07:48:29 -0800, "carneyke"

Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with and
you.........

And you...? You are ignorant.


Yes, Jim. That means he's "teachable". You, on the other hand, are merely
a fool.

Good Luck!
Rich
--
"We have met the enemy and he is us." - Pogo Possum

On Mon, 13 Feb 2006 08:06:58 -0800, carneyke wrote:

Sorry. That was a little pompous on my part.

Don't ever apologize for exposing the folly of a fool. ;-P

And learn how to operate googlegroups - don't click the "reply" link at
the bottom of the post - scroll up to the top of the post, at the header,
and click the "show options" link - then, click _that_ "reply" link, and
google will quote context for you.

Thanks!
Rich
--
"We have met the enemy and he is us." - Pogo Possum

On Mon, 13 Feb 2006 16:20:18 +0000, Pooh Bear wrote:
carneyke wrote:
Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with and
you.........

I was simply pointing out that the heat generated is in direct relation to
the quantity of fuel used, as opposed to internal working temperatures
where higher temps often means improved efficiency which actually reduces
the overal heat output, like for like.

Of course if certain countries in particular would consider using smaller
engined vehicles then this problem could be vastly ameliorated. Many of
today's cars have power well beyond what is actually reasonably *required*
for personal transportation and as such, this profiligate use of energy
can be considered to be a luxury use.

Graham

Hey! That's it! Tax The Rich!

Wonder howcome nobody's thought of that yet? ;-P

Cheers!
Rich (not "the" rich, that's just my name. )-; )
--
"We have met the enemy and he is us." - Pogo Possum

On Mon, 13 Feb 2006 09:38:35 -0700, Jim Thompson wrote:
On Mon, 13 Feb 2006 16:20:18 +0000, Pooh Bear
carneyke wrote:

Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with and
you.........

I was simply pointing out that the heat generated is in direct relation to
the quantity of fuel used, as opposed to internal working temperatures
where higher temps often means improved efficiency which actually reduces
the overal heat output, like for like.

Of course if certain countries in particular would consider using smaller
engined vehicles then this problem could be vastly ameliorated. Many of
today's cars have power well beyond what is actually reasonably *required*
for personal transportation and as such, this profiligate use of energy
can be considered to be a luxury use.

Naaah! I find 340 HP and 333 ft-lb just right ;-)


Have you beat the train to the crossing yet? ;-)

Conspicuous consumption is, after all, the hallmark of the rich, white,
fat, happy idiot savants.

Good Luck!
Rich

--
"We have met the enemy and he is us." - Pogo Possum

On Mon, 13 Feb 2006 08:45:23 -0800, carneyke wrote:

Graham , Jim & John
Sorry for being rude and ignorant.

You're sucking up to the wrong trolls.

"Ignorant" means "teachable." "Stupid" means "I refuse to learn".
Graham, Jim, and at least one of the Johns around here are kind of
brain-damaged, and need adult supervision.

And just because some neocon weenie calls you "rude" doesn't mean
you're supposed to bow and scrape before them - don't cast your
pearls before swine, and all that.

Cheers!
Rich
--
"We have met the enemy and he is us." - Pogo Possum

On Mon, 13 Feb 2006 16:20:18 +0000, Pooh Bear
wrote:


Of course if certain countries in particular would consider using smaller
engined vehicles

Countries don't use vehicles, people use vehicles. But yes, all those
Land Rovers and Rolls and Jags are energy hogs.

John

On Mon, 13 Feb 2006 19:21:22 GMT, Richard the Dreaded Libertarian
wrote:

On Mon, 13 Feb 2006 08:45:23 -0800, carneyke wrote:

Graham , Jim & John
Sorry for being rude and ignorant.

You're sucking up to the wrong trolls.

"Ignorant" means "teachable." "Stupid" means "I refuse to learn".
Graham, Jim, and at least one of the Johns around here are kind of
brain-damaged, and need adult supervision.


I always welcome adult supervision, as long as they work for me.

John

But yes, all those
Land Rovers and Rolls and Jags are energy hogs.

=================================

Amongst the most polluting of energy hogs are aircraft engines.

Ban all motor vehicles and airliners and let the World slow down!

Pooh Bear writes:

Ken Smith wrote:

In article ,
Charles Schuler wrote:
[...]
Global warming is a widely disputed theory.

The warming isn't very disputed. It is the cause that is being argued
about these days.

Very true.

Even the US contingent that say it's *not* due to human activity don't dismiss
the effect of CO2 in the atmosphere though AFAIK. They simply dispute how much
an influence it is.

The sane conclusion therefore is to limit CO2 ( and other greenhouse gas )
emissions since it can at worst do no harm to do so !

Judging from some responses I see here, the USA will go directly from
"there's no problem" to "it's *too late* to do anything about it
anyway". Skipping entirely the "it looks like there is a problem,
perhaps we shouldn't make it worse" phase.

--

John Devereux

"carneyke" wrote in message
oups.com...
Yeah, I am a little behind the times (Climate Change terminology being
in Vouge). On a serious note, this summer I read an article on
automobile registration in the USA. In 1975 (year I graduated from High
School) there were roughly 130 million cars registered. Today it is
around 280 million cars (I may be off on these numbers slightly).
Anyway, if you remember, cars ran at 160 degree F back then and today
they run at 200 degree F. They also have that hot little catalytic
converter. I truly believe, the doubling of cars (with catalytic
converters) and the 25 % increase in engine temperature must have some
effect on the atmosphere. I know this has been kicked around but the
article really opened my eyes to the heat generated by cars. I guess
this is a case of fixing one problem and creating another. Take Care

High school physics: the amount of heat produced by an automobile
corresponds directly to the amount of fuel that's burned. Considering that
the percentage of fuel that's burned today is just slightly higher than it
was then, the operating temperature has nothing to do with it.

In the old days, more heat just went out the tailpipe.

--
Ed Huntress

"carneyke" wrote in message
oups.com...
Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with and
you.........

Too much "common sense." Too little understanding of physics.

That's the kind of "common sense" that had people telling us their vehicles
got their best fuel mileage at 65 mph.

--
Ed Huntress

On Mon, 13 Feb 2006 20:49:47 +0000, John Devereux wrote:
Pooh Bear writes:
Ken Smith wrote:
Charles Schuler wrote:
[...]
Global warming is a widely disputed theory.

The warming isn't very disputed. It is the cause that is being argued
about these days.

Very true.

Even the US contingent that say it's *not* due to human activity don't dismiss
the effect of CO2 in the atmosphere though AFAIK. They simply dispute how much
an influence it is.

The sane conclusion therefore is to limit CO2 ( and other greenhouse gas )
emissions since it can at worst do no harm to do so !

Judging from some responses I see here, the USA will go directly from
"there's no problem" to "it's *too late* to do anything about it
anyway". Skipping entirely the "it looks like there is a problem,
perhaps we shouldn't make it worse" phase.

Or, maybe, one day, they'll outgrow the "I AM MASTER OF THE WORLD, AND I
SHALL DICTATE WHAT THE CLIMATE OF THE ENTIRE PLANET WILL BE" phase.

Lotsa Luck!
Rich

On Mon, 13 Feb 2006 11:38:44 -0800, John Larkin wrote:
On Mon, 13 Feb 2006 16:20:18 +0000, Pooh Bear

Of course if certain countries in particular would consider using smaller
engined vehicles

Countries don't use vehicles, people use vehicles. But yes, all those
Land Rovers and Rolls and Jags are energy hogs.


I'd be willing to bet real money that if the USA stood down their military,
and called off all of the invasions and crusades and other mischief
they're perpetrating all over the world, that worldwide oil consumption
would decrease by 25-50%.

Cheers!
Rich
--
Elect Me President in 2008! I will:
A. Fire the IRS, and abolish the income tax
B. Legalize drugs
C. Stand down all military actions by the US that don't involve actual
military aggression against US territory
D. Declare World Peace I.

On Mon, 13 Feb 2006 22:43:08 GMT, Rich Grise wrote:

I'd be willing to bet real money that if the USA stood down their military,
and called off all of the invasions and crusades and other mischief
they're perpetrating all over the world, that worldwide oil consumption
would decrease by 25-50%.

I'd be willing to bet real money that you just pulled that number out of
your ass.

"Pooh Bear" wrote in message
...

carneyke wrote:

Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with and
you.........

I was simply pointing out that the heat generated is in direct relation to
the quantity of fuel used, as opposed to internal working temperatures
where higher temps often means improved efficiency which actually reduces
the overal heat output, like for like.

Of course if certain countries in particular would consider using smaller
engined vehicles then this problem could be vastly ameliorated. Many of
today's cars have power well beyond what is actually reasonably *required*
for personal transportation and as such, this profiligate use of energy
can be considered to be a luxury use.

Graham

Compared to some others in this thread, Graham, you're a physics genius.
However, putting relative efficiency aside, engine size is not as great a
factor as some think, and is far less of a factor today than it was 20 years
ago.

If it requires 50 hp to drive a car at a certain speed, it doesn't matter
(in theory) whether that comes from an engine that produces 50 hp or one
that can produce 200. However, the 200 hp engine would have to be geared
down (lower rpm for a given speed) to produce comparable efficiency, because
the big factor here is effective compression ratio. The larger engine is
running at a lower compression ratio, if it's producing only a fraction of
its potential torque at a given number of rpm, and that hurts it thermal
efficiency. (We're assuming spark-ignition engines here; diesels are another
kettle of fish.)

The peak-efficiency range of an engine is fairly narrow: too high, and you
have too much internal friction. Too low, and you have too much heat loss to
cylinder walls, piston crown, and combustion chamber.

But modern fuel injection and ignition timing can result in similar
*combustion* efficiency over quite a range of rpm. When the engine gets too
big relative to its normal operating demands, "gearing it down" will put it
in the too-low range of rpm. If you gear it for somewhat higher rpm (and
this is the normal condition), the engine is operating at a fraction of its
design compression ratio, and thermal efficiency goes to hell.

Overall, the mpg of cars with larger engines vs. smaller ones falls in a
narrower range than it used to. But there is still a spread, for the reasons
above. The big factors are total car weight and total drag (air drag plus
rolling resistance) and internal friction in the total driveline. Bigger
cars suck up more gas, even with relatively small engines.

Here's a sidelight that you may find interesting: When direct-port injection
had reached a fairly good level of sophistication, BMW ran tests on how much
fuel was required to reach a given speed. Unlike the conventional wisdom,
best efficiency in reaching speed was achieved at FULL THROTTLE, but also by
shifting at relatively low rpm. Effective compression ratio was near its
max; heat loss to cylinders was balanced by internal friction; and there was
nothing to be gained by accelerating more slowly.

So much for conventional wisdom. It goes in the crapper, along with "common
sense."

--
Ed Huntress

On Mon, 13 Feb 2006 17:32:38 -0500, "Ed Huntress"
wrote:

"carneyke" wrote in message
roups.com...
Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with and
you.........

Too much "common sense." Too little understanding of physics.

That's the kind of "common sense" that had people telling us their vehicles
got their best fuel mileage at 65 mph.

I had occasion to drive a 1977 280Z from Phoenix to Houston, solo...
the wife and children flew, so I conducted an experiment, driving one
hour intervals at fixed speed.

(I was working on fuel metering at the time, so I had a breadboard in
the car that gave me accurate consumption readings.)

The mileage did indeed peak pretty close to 65MPH... around 28MPG
IIRC, but had only fallen to 23MPG at 100MPH.

But the 280Z was fairly light (2355#), pretty aerodynamic, and was
rated at around 21MPG _average_. (1977 was when the 5-speed manual
tranny was added.)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

Yellow Journalism has returned with a new definition... I'm afraid!

"carneyke" wrote in message
oups.com...
I think my point is for everything we do there
will always be a "bad" side and its a shame it gets so political. So
please accept my appollogy for being rude and as Jim wrote "Ignorant".
Sorry Jim.....

Gee, you must be coming from an awfully polite newsgroup. g

FWIW, most of the fuel you burn in your car goes out the tailpipe. A
super-efficient spark-ignition engine turns something like 24% of its fuel
into motive power (if my memory of this number is not accurate, someone
please correct me; I haven't looked it up for years). Of that, something
like 60% makes it to the drive wheels. So a spark-ignition-engined car, on a
good day, delivers somewhere around 15% of the thermal potential of the
fuel, as motive power to the wheels.

It doesn't get a lot better with other engine types. A large, efficient,
stationary diesel is good for something like 28% at the shaft. The number is
similar for a huge, stationary, multi-stage steam turbine. And, believe it
or not, also for a Stirling, running with helium or hydrogen for a working
fluid, at very high internal gas pressure and with a high-efficiency heat
exchanger at each end.

Sucks, doesn't it? And that's on a good day. d8-)

--
Ed Huntress

"Jim Thompson" wrote in
message ...
On Mon, 13 Feb 2006 17:32:38 -0500, "Ed Huntress"
wrote:

"carneyke" wrote in message
roups.com...
Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with and
you.........

Too much "common sense." Too little understanding of physics.

That's the kind of "common sense" that had people telling us their
vehicles
got their best fuel mileage at 65 mph.

I had occasion to drive a 1977 280Z from Phoenix to Houston, solo...
the wife and children flew, so I conducted an experiment, driving one
hour intervals at fixed speed.

(I was working on fuel metering at the time, so I had a breadboard in
the car that gave me accurate consumption readings.)

The mileage did indeed peak pretty close to 65MPH... around 28MPG
IIRC, but had only fallen to 23MPG at 100MPH.

But the 280Z was fairly light (2355#), pretty aerodynamic, and was
rated at around 21MPG _average_. (1977 was when the 5-speed manual
tranny was added.)

To the degree that was an accurate measurement, Jim, it likely was a factor
of the crappy thermal efficiency that resulted from running that car at
part-throttle and resulting low effective compression ratio, combined with
the crappy combustion efficiency we got from carburetors or throttle-body
fuel-injection (or even some of the early direct-port injection) running at
less than their top cruise flow-rates.

So, what did you get at 45 mph? It should have been much better, except for
the factors above.

--
Ed Huntress

On 13 Feb 2006 22:47:04 GMT, Dave Hinz wrote:

On Mon, 13 Feb 2006 22:43:08 GMT, Rich Grise wrote:

I'd be willing to bet real money that if the USA stood down their military,
and called off all of the invasions and crusades and other mischief
they're perpetrating all over the world, that worldwide oil consumption
would decrease by 25-50%.

I'd be willing to bet real money that you just pulled that number out of
your ass.

While smoking pot ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

Yellow Journalism has returned with a new definition... I'm afraid!

Ed Huntress wrote:

"carneyke" wrote in message
oups.com...
I think my point is for everything we do there
will always be a "bad" side and its a shame it gets so political. So
please accept my appollogy for being rude and as Jim wrote "Ignorant".
Sorry Jim.....

Gee, you must be coming from an awfully polite newsgroup. g

FWIW, most of the fuel you burn in your car goes out the tailpipe. A
super-efficient spark-ignition engine turns something like 24% of its fuel
into motive power (if my memory of this number is not accurate, someone
please correct me; I haven't looked it up for years). Of that, something
like 60% makes it to the drive wheels. So a spark-ignition-engined car, on a
good day, delivers somewhere around 15% of the thermal potential of the
fuel, as motive power to the wheels.

It doesn't get a lot better with other engine types. A large, efficient,
stationary diesel is good for something like 28% at the shaft. The number is
similar for a huge, stationary, multi-stage steam turbine. And, believe it
or not, also for a Stirling, running with helium or hydrogen for a working
fluid, at very high internal gas pressure and with a high-efficiency heat
exchanger at each end.

Sucks, doesn't it? And that's on a good day. d8-)

Even electricity generation is no better than 37% efficient apparently ( recent
UK figure ).

Graham

"Pooh Bear" wrote in message
...


Ed Huntress wrote:

"carneyke" wrote in message
oups.com...
I think my point is for everything we do there
will always be a "bad" side and its a shame it gets so political. So
please accept my appollogy for being rude and as Jim wrote "Ignorant".
Sorry Jim.....

Gee, you must be coming from an awfully polite newsgroup. g

FWIW, most of the fuel you burn in your car goes out the tailpipe. A
super-efficient spark-ignition engine turns something like 24% of its
fuel
into motive power (if my memory of this number is not accurate, someone
please correct me; I haven't looked it up for years). Of that, something
like 60% makes it to the drive wheels. So a spark-ignition-engined car,
on a
good day, delivers somewhere around 15% of the thermal potential of the
fuel, as motive power to the wheels.

It doesn't get a lot better with other engine types. A large, efficient,
stationary diesel is good for something like 28% at the shaft. The
number is
similar for a huge, stationary, multi-stage steam turbine. And, believe
it
or not, also for a Stirling, running with helium or hydrogen for a
working
fluid, at very high internal gas pressure and with a high-efficiency
heat
exchanger at each end.

Sucks, doesn't it? And that's on a good day. d8-)

Even electricity generation is no better than 37% efficient apparently (
recent
UK figure ).

Graham

Well, even that is somewhat higher than I recall, because the steam-turbine
example above is for one engaged in generating electricity.

However, my memory isn't that precise, and is getting less so, and
technology no doubt has improved. A turbine's practical efficiency isn't a
factor of theoretical heat cycles as much as it is a matter of how much heat
and erosion it can tolerate.

In regard to gas turbines, I visited Pratt & Whitney's engine division
decades ago on a press junket, to hear them tell us how they'd raised the
operating temperature of a jet engine by roughly 100 degrees F, from 2,200
to 2,300 degrees. I remarked that didn't really sound very impressive. An
old P&W engineer sitting next to me said, "Son [I was much younger then
g]," there are men here who would sell their grandmothers for another
hundred degrees."

--
Ed Huntress

On Mon, 13 Feb 2006 18:19:34 -0500, "Ed Huntress"
wrote:

"Jim Thompson" wrote in
message ...
On Mon, 13 Feb 2006 17:32:38 -0500, "Ed Huntress"
wrote:

"carneyke" wrote in message
roups.com...
Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with and
you.........

Too much "common sense." Too little understanding of physics.

That's the kind of "common sense" that had people telling us their
vehicles
got their best fuel mileage at 65 mph.

I had occasion to drive a 1977 280Z from Phoenix to Houston, solo...
the wife and children flew, so I conducted an experiment, driving one
hour intervals at fixed speed.

(I was working on fuel metering at the time, so I had a breadboard in
the car that gave me accurate consumption readings.)

The mileage did indeed peak pretty close to 65MPH... around 28MPG
IIRC, but had only fallen to 23MPG at 100MPH.

But the 280Z was fairly light (2355#), pretty aerodynamic, and was
rated at around 21MPG _average_. (1977 was when the 5-speed manual
tranny was added.)

To the degree that was an accurate measurement, Jim, it likely was a factor
of the crappy thermal efficiency that resulted from running that car at
part-throttle and resulting low effective compression ratio, combined with
the crappy combustion efficiency we got from carburetors or throttle-body
fuel-injection (or even some of the early direct-port injection) running at
less than their top cruise flow-rates.

So, what did you get at 45 mph? It should have been much better, except for
the factors above.

It actually was worse. The 1977 280Z had injection into the
(straight-6) manifold at multiple points with "air-door" control.

Instrumentation was a combination of a positive displacement flow
meter plus a calibrated float in the tank... a precursor to modern
"miles-to-go" systems... with a _discrete_logic_ "microprocessor"
doing all the data churning ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

Yellow Journalism now has a new definition... guess what it is?

Reg Edwards wrote:

But yes, all those
Land Rovers and Rolls and Jags are energy hogs.

=================================

Amongst the most polluting of energy hogs are aircraft engines.

Ban all motor vehicles and airliners and let the World slow down!

Airbus quote 3 litres of fuel used per 100 pasenger km - approx
equivalent to ~ 50 UK mpg or ~ 40 US mpg. Better than a car with a
sole occupant at least.

Of course the long distance of many airline flights means a large
amount of fuel is used. Chances are most ppl would think twice about
the need to visit their their destination if they had to drive.

Graham

Ed Huntress wrote:

Even electricity generation is no better than 37% efficient apparently (
recent
UK figure ).

Graham

Well, even that is somewhat higher than I recall, because the steam-turbine
example above is for one engaged in generating electricity.

However, my memory isn't that precise, and is getting less so, and
technology no doubt has improved. A turbine's practical efficiency isn't a
factor of theoretical heat cycles as much as it is a matter of how much heat
and erosion it can tolerate.

I came across that figure in a thread in another ng recently. Apparently up from
35% only a few years ago. There's been quite a lot of new generation built
recently in the UK using natural gas which may explain the improvement. It also
entertainly shows how short term thinking ( natural gas is cheap - so lets burn
it ) can blow up in your face !


In regard to gas turbines, I visited Pratt & Whitney's engine division
decades ago on a press junket, to hear them tell us how they'd raised the
operating temperature of a jet engine by roughly 100 degrees F, from 2,200
to 2,300 degrees. I remarked that didn't really sound very impressive. An
old P&W engineer sitting next to me said, "Son [I was much younger then
g]," there are men here who would sell their grandmothers for another
hundred degrees."

A friend of mine works in aeropsace design. I'm awed by the tricks they use to
cool those turbine blades. They would melt otherwise !

Graham

Maybe you are right, but when they converted to the catalytic convertor
and raised the operating temperature, the engine compartment through
off much more heat. I guess you are right, putting it in a common sense
way (either the heat went up the tailpipe or given off by the engine
compartment). I didn't take High School Physics, went the electric shop
route with the other "sparkies". Made a damn good living at it too....

Too much "common sense." Too little understanding of physics.

That's the kind of "common sense" that had people telling us their vehicles
got their best fuel mileage at 65 mph.

--
Ed Huntress

"Jim Thompson" wrote in
message ...
On Mon, 13 Feb 2006 18:19:34 -0500, "Ed Huntress"
wrote:

"Jim Thompson" wrote in
message ...
On Mon, 13 Feb 2006 17:32:38 -0500, "Ed Huntress"
wrote:

"carneyke" wrote in message
roups.com...
Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate
much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense, I was blessed with
and
you.........

Too much "common sense." Too little understanding of physics.

That's the kind of "common sense" that had people telling us their
vehicles
got their best fuel mileage at 65 mph.

I had occasion to drive a 1977 280Z from Phoenix to Houston, solo...
the wife and children flew, so I conducted an experiment, driving one
hour intervals at fixed speed.

(I was working on fuel metering at the time, so I had a breadboard in
the car that gave me accurate consumption readings.)

The mileage did indeed peak pretty close to 65MPH... around 28MPG
IIRC, but had only fallen to 23MPG at 100MPH.

But the 280Z was fairly light (2355#), pretty aerodynamic, and was
rated at around 21MPG _average_. (1977 was when the 5-speed manual
tranny was added.)

To the degree that was an accurate measurement, Jim, it likely was a
factor
of the crappy thermal efficiency that resulted from running that car at
part-throttle and resulting low effective compression ratio, combined
with
the crappy combustion efficiency we got from carburetors or throttle-body

fuel-injection (or even some of the early direct-port injection) running
at
less than their top cruise flow-rates.

So, what did you get at 45 mph? It should have been much better, except
for
the factors above.

It actually was worse. The 1977 280Z had injection into the
(straight-6) manifold at multiple points with "air-door" control.

Instrumentation was a combination of a positive displacement flow
meter plus a calibrated float in the tank... a precursor to modern
"miles-to-go" systems... with a _discrete_logic_ "microprocessor"
doing all the data churning ;-)

All else being equal, light cars typically get their best mileage at just
over 50 mph, and heavy ones somewhere between 45 and 50 mph. There are many
factors involved, including engine design.

The 280Z had a pretty advanced FI system -- yours might have been an early
Bosch L-Jetronic -- and it was fairly slick. Even so, though, to get peak
mileage at 65 mph, where drag has already become a significant factor,
speaks more to how lousy the system worked at lower speeds. g The
semi-sporty nature of that engine may have involved a lot of valve overlap
or large exhaust valves, both of which knock your low-rpm, low-load mileage
to hell.

In any case, even getting peak efficiency at 50 mph tells us not that the
car has high efficiency at higher speeds, but that the car has poor
efficiency at lower speeds, mostly for the reasons we've discussed.

--
Ed Huntress

"carneyke" wrote in message
oups.com...
Maybe you are right, but when they converted to the catalytic convertor
and raised the operating temperature, the engine compartment through
off much more heat. I guess you are right, putting it in a common sense
way (either the heat went up the tailpipe or given off by the engine
compartment). I didn't take High School Physics, went the electric shop
route with the other "sparkies". Made a damn good living at it too....

Well, that beats what's happened in *my* field lately. g

As a couple of people have intimated, the heat from the cat is just heat (or
unburned fuel) that would have gone straight out the tailpipe, without the
cat. It's true that today's engines burn more inside the engine and less
goes out as heat or as unburned hydrocarbons. But not that much as a
percentage, overall. Some of that which *doesn't* go out the tailpipe goes
off as waste heat from the cat (as you've identified) and some goes off in
engine cooling (as you've also identified). But some very small portion
winds up as power at the wheels -- where it then gets turned into heat of
friction. d8-)

It all goes out as heat, one way or another, or as polluting, unburned
hydrocarbons or products of them (such as carbon monoxide, which will burn).
'Ain't no free lunch.

--
Ed Huntress

In article ,
Richard the Dreaded Libertarian wrote:
On Sun, 12 Feb 2006 22:57:32 +0000, Ken Smith wrote:
[snipped global warming hysteria rants]
... we
have concluded that it is best to "play it safe".


First, who's "we"? Got a mouse in your pocket?

No, "we" means evereyone else but you. We are conspiring against you. I
thought you'd figured that out.


[...]
Is that an experiment we really want to undertake?

We are doomed to be part of the experiment no matter what we do. We will
either continue to make more and more CO2 or we will reduce it. Our cars
can average 15 MPG or 30. In either case we can't back up and try the
other way to see if it comes out different.

--
--
forging knowledge

In article .com,
carneyke wrote:
Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense,

This is wrong. Todays cars use less gas partly because they make less
heat than those of the 70's
--
--
forging knowledge

In article ,
Jim Thompson wrote:
[...]
Naaah! I find 340 HP and 333 ft-lb just right ;-)

So what kind of motorcycle is it?
--
--
forging knowledge

"Jim Thompson" wrote in
message ...


Sorry but I remembered poorly. Thinking about it, I was never below
55MPH, so it's possible with that manifold style injection the MPG got
better at lower speeds. But 65MPH was definitely better than 55MPH.

It would be interesting to see how that worked out on a complete curve, but
there are so many factors involved in a car that has anything special about
it for performance that it wouldn't tell us much about the generalities.

My '58 Alfa Romeo with full-race Tom O'Brien motor would hardly run at all
below 40 mph. I think it sprayed raw gas out of the tailpipe at that speed.
g

--
Ed Huntress

Good ****ing grief, Charlie Brown.

Do you ever watch the weather?

You know, when they say the high today was 46, and in 1941, the high for
today was 66? If global warming was a reality, and the temperature rose
since 1941, it probably would have been 146 degrees today!

Temperatures are freaky spikes in nature. Up one year and down the next.

Reading anything else into it is utter paranoia.

Get over it. Or go get some therapy.

Steve

"Steve B" wrote in message
news:8EcIf.38834$JT.22325@fed1read06...
Good ****ing grief, Charlie Brown.

Do you ever watch the weather?

You know, when they say the high today was 46, and in 1941, the high for
today was 66? If global warming was a reality, and the temperature rose
since 1941, it probably would have been 146 degrees today!

Temperatures are freaky spikes in nature. Up one year and down the next.

Reading anything else into it is utter paranoia.

Get over it. Or go get some therapy.

Steve

Steve, is that supposed to be an argument regarding global warming? I'm
serious here. I think an average 10-year-old can do better.

You're looking at ONE DAY, comparing ONE PAIR OF YEARS. Does the inanity of
that not strike you right between the eyes?

I mean, c'mon. Nobody is that numb.

--
Ed Huntress

On Mon, 13 Feb 2006 18:03:39 -0500, Ed Huntress wrote:
"carneyke" wrote in message
oups.com...
I think my point is for everything we do there
will always be a "bad" side and its a shame it gets so political. So
please accept my appollogy for being rude and as Jim wrote "Ignorant".
Sorry Jim.....

Gee, you must be coming from an awfully polite newsgroup. g

FWIW, most of the fuel you burn in your car goes out the tailpipe. A
super-efficient spark-ignition engine turns something like 24% of its fuel
into motive power (if my memory of this number is not accurate, someone
please correct me; I haven't looked it up for years). Of that, something
like 60% makes it to the drive wheels. So a spark-ignition-engined car, on a
good day, delivers somewhere around 15% of the thermal potential of the
fuel, as motive power to the wheels.

It doesn't get a lot better with other engine types. A large, efficient,
stationary diesel is good for something like 28% at the shaft. The number is
similar for a huge, stationary, multi-stage steam turbine. And, believe it
or not, also for a Stirling, running with helium or hydrogen for a working
fluid, at very high internal gas pressure and with a high-efficiency heat
exchanger at each end.

Sucks, doesn't it? And that's on a good day. d8-)

Speaking of losing memory neurons, I seem to recall seeing a sort of
diagram, back in the '50's, when they had flat-head straight 6's, that
something like 2% of the potential power in the fuel actually got to the
wheels.

There were HUGE thermal losses, and friction, and yadda yadda yadda...

Thanks!
Rich

On Tue, 14 Feb 2006 00:09:30 +0000, Pooh Bear wrote:
Ed Huntress wrote:
Even electricity generation is no better than 37% efficient apparently (
recent
UK figure ).

Well, even that is somewhat higher than I recall, because the steam-turbine
example above is for one engaged in generating electricity.

However, my memory isn't that precise, and is getting less so, and
technology no doubt has improved. A turbine's practical efficiency isn't a
factor of theoretical heat cycles as much as it is a matter of how much heat
and erosion it can tolerate.

I came across that figure in a thread in another ng recently. Apparently up from
35% only a few years ago. There's been quite a lot of new generation built
recently in the UK using natural gas which may explain the improvement. It also
entertainly shows how short term thinking ( natural gas is cheap - so lets burn
it ) can blow up in your face !


In regard to gas turbines, I visited Pratt & Whitney's engine division
decades ago on a press junket, to hear them tell us how they'd raised the
operating temperature of a jet engine by roughly 100 degrees F, from 2,200
to 2,300 degrees. I remarked that didn't really sound very impressive. An
old P&W engineer sitting next to me said, "Son [I was much younger then
g]," there are men here who would sell their grandmothers for another
hundred degrees."

A friend of mine works in aeropsace design. I'm awed by the tricks they use to
cool those turbine blades. They would melt otherwise !


I was on a document coding project where somebody was suing somebody else
about inferior turbine blades. They're like, a single crystal of titanium
that's grown in a mold, and if you drop one on the floor, you have to
scrap it. I think maybe even if you touch it with bare fingers, you have
to scrap it. It seems a new jet engine is about $2,000,000.00, but an
overhaul, where they basically replace all of the turbine blades and
bearings, is only about $250,000.00. Or, was in the 1990's. :-)

Cheers!
Rich

On Mon, 13 Feb 2006 23:32:42 +0000, Pooh Bear wrote:
Reg Edwards wrote:

But yes, all those
Land Rovers and Rolls and Jags are energy hogs.

Amongst the most polluting of energy hogs are aircraft engines.

Ban all motor vehicles and airliners and let the World slow down!

Airbus quote 3 litres of fuel used per 100 pasenger km - approx
equivalent to ~ 50 UK mpg or ~ 40 US mpg. Better than a car with a
sole occupant at least.

Of course the long distance of many airline flights means a large
amount of fuel is used. Chances are most ppl would think twice about
the need to visit their their destination if they had to drive.


I've been on a couple of excruciatingly long overseas flights - like,
14 hours of cruising across the Pacific[1], and I wonder where the hell
they keep all of that fuel? The fuel lines on those engines are, like,
2" (5 cm) or so in diameter! (well, the ones I've seen on USAF fighter
jets.)

Thanks!
Rich
[1] I took along a copy of Frank Herbert's "Dune", and it turned out
that watching the ocean go by in the moonlight was measurably less boring,
and infinitely more comprehensible! ;-)

On Mon, 13 Feb 2006 22:47:04 +0000, Dave Hinz wrote:

On Mon, 13 Feb 2006 22:43:08 GMT, Rich Grise wrote:

I'd be willing to bet real money that if the USA stood down their military,
and called off all of the invasions and crusades and other mischief
they're perpetrating all over the world, that worldwide oil consumption
would decrease by 25-50%.

I'd be willing to bet real money that you just pulled that number out of
your ass.

I'm not gonna take that bet, 'cause you'd win. ;-) Did you know that in
The Netherlands, that same expression translates to "sucked it out of your
thumb"? ;-P I explained to my coworker, a Hollandaise guy, ;-) that
sometimes it's "pulled it out of the air". ;-) He also taught me
"zaadvragende ogen". leer, snort ;-P

Cheers!
Rich
--- - munged siggie thingie, to promulgate my campaign. :-)
Elect Me President in 2008! I will:
A. Fire the IRS, and abolish the income tax
B. Legalize drugs
C. Stand down all military actions by the US that don't involve actual
military aggression against US territory
D. Declare World Peace I.

On Mon, 13 Feb 2006 16:20:18 -0700, Jim Thompson wrote:
On 13 Feb 2006 22:47:04 GMT, Dave Hinz wrote:
On Mon, 13 Feb 2006 22:43:08 GMT, Rich Grise wrote:

I'd be willing to bet real money that if the USA stood down their military,
and called off all of the invasions and crusades and other mischief
they're perpetrating all over the world, that worldwide oil consumption
would decrease by 25-50%.

I'd be willing to bet real money that you just pulled that number out of
your ass.

While smoking pot ;-)


Does that disturb your delicate little puritan sensibilities?

Thanks!
Rich
--
Elect Me President in 2008! I will:
A. Fire the IRS, and abolish the income tax
B. Legalize drugs
C. Stand down all military actions by the US that don't involve actual
military aggression against US territory
D. Declare World Peace I.

On Mon, 13 Feb 2006 06:10:13 +0000, Pooh Bear
wrote:



John Popelish wrote:

Don Klipstein wrote:
(snip)
Looks like some recent record-big blizzards did not stop the world from
having its hottest year on record as a continuation of a recent-decades
upward trend, and less lignificantly the USA from having its hottest
January on record - should one more blizzard make much difference?

Global warming does not necessarily imply less snow, since warmer air
holds more moisture than colder air, allowing it to deliver more snow.
Only when global warming brings a particular location above the
freezing point, does it imply rain instead of snow. Expect places
that normally have had dry, cold winters to have warmer winters with
lots more snow. Till it gets lots warmer.

The warming is best measured by sea temp not air temp. There's a lot more
energy tied up in seawater than the atmosphere.

Note also that Katrina was as bad as it was due to higher sea temps in the
Atlantic and Gulf that also ensured that the air was moisture-laden thus
helping to increase the severity of the Hurricane.

Graham




If I recall correctly, the planet has been experiencing "global
warming" since the last ice age, about 13,000 years ago.

And before that ice age was a "global warming" that lasted several
thousand years until the ice age arrived.

And so on going back for severa such several-millenia l cycles.

But of course it's SUV's that are the root cause of THIS warming
trend..

Nevermind the fact that a single volcanic eruption can dump more
"greenhouse" gases into the atmosphere in a week than the human race
has produced since the first hominoid climbed out of the trees, it's
STILL SUV's that are the root cause of THIS warming trend.

I think some people have an inflated opinion of the human race's
importance.

Mike

Mike Patterson
Please remove the spamtrap to email me.
"I always wanted to be somebody...I should have been more specific..." - Lily Tomlin