Frank F. Matthews

The Reid wrote:
    > Following up to walter

    >>Yes, as many drivers of cheap cars have a jealousy complex when they
    >>see an expensive one: "You drive a 100000 buck Mercedes. I have only a
    >>Harakiri 1200 from Korea, and I blame you for this!"
    >>Very common here in Germany.

    > Yes, Walter, I drive a BMW and many people in the driving
    > newsgroup here exhibit all the symptoms of jealously of
    > BMW/Mercedes etc drivers. (although to be honest BMW drivers do
    > tend to be fast drivers here and are disliked by the "middle lane
    > whatever, clenching the wheel with white knuckles, mouth open"
    > type of driver).

Nah! It's the arrogance of some of them that gets to me. I enjoy
complaining to security and getting the cars improperly parked booted.
Strangely, they tend to be almost always Lexus, Mercedes, or BMWs. FFM

Earl Evleth

On 3/03/04 16:34, in article
[email protected] , "Tim Challenger"
<"timothy(dot)challenger(at)apk(dot)at"> wrote:

    > On Wed, 03 Mar 2004 09:17:13 -0600, Olivers wrote:
    >
    >>> That makes 165kg / trabi / year.
    >>
    >> No, if it was a Trabi, you get to count the weight of the parts and pieces
    >> which annually became detached from the corpus indelectus.
    >
    > :-)
    >
    > But could be replace by a bit of papier mache and airfix paint.

Any estimate on the pollution performance of a 2CV??

Earl

Jesper Lauridsen

On Sun, 29 Feb 2004 12:50:41 -0000, "Keith Willshaw" <[email protected]> wrote:

    >"Tim Kroesen" <[email protected]> wrote in message
    >news:[email protected]...
    >> Why would carrying any argument to the nth degree be logical for every
    >> subject and instance?
    >It isnt , but it shows that a statement that safety is the only thing that
    >matters is patently false. Policy in this area is a compromise between
    >safety, cost and convenience.

Yes, the argument that "X deaths are X too many" is crap, as the only way to
reach zero is to force everyone too stay home. Unless one is prepared to go
that far, one has to accept that accidents will happen and that it's possible
to go too far in the pursuit of safety.

Keith Willshaw

"Tim Challenger" <"timothy(dot)challenger(at)apk(dot)at"> wrote in message
news:[email protected]...
    > On Wed, 3 Mar 2004 13:52:41 -0000, Keith Willshaw wrote:
    > > "Earl Evleth" <[email protected]> wrote in message
    > > news:BC6B9A86.28826%[email protected]...
    > >> On 3/03/04 13:15, in article [email protected], "Keith
    > >> Willshaw" <[email protected]> wrote:
    > >>
    > >>> Trouble as studies have shown it emits 10 times more
    > >>> pollutants than the average western car
    > >>
    > >> Since there only are a couple running around, no big deal!
    > >>
    > >> Earl
    > >>
    > >
    > > In Germany perhaps but at the peak there were 120,000
    > > of them on the roads of Budapest and the city council
    > > estimated that taking just 2,000 off the roads reduced the
    > > pollution load by 331,000 kg per year
    > >
    > > Keith
    > I think your figures ar a bit suspect.

The figures came from the Hungarians

    > That makes 165kg / trabi / year.
    > The 1995 average CO2 for cars in the EU was 186g/km.
    > So assuming the average car does say 15000km year (just guessing what a
    > trabi might do),it would produce : 186x15000/1000 = 2790kg CO2 per year.
    > This would mean that a trabi would on avearage drive only 887km per year,
    > OR only emmit 1/16th the pollution per km of an average car.

They were looking at pollutants that cause immediate damage, specifically
particulates, unburned hydrocarbons and NOx which the Trabi produces
at 10 times the rate of modern western cars

One Hungarian official described the Trabi as "a mobile chemical weapon that
ought
to be tabled at the Geneva talks on chemical weapons disarmament".

CO2 while a greenhouse gas is not normally considered in the list
of pollutants in such surveys.

Keith

Tim Challenger

On Wed, 3 Mar 2004 16:54:56 -0000, Keith Willshaw wrote:

    > "Tim Challenger" <"timothy(dot)challenger(at)apk(dot)at"> wrote in message
    > news:[email protected]...
    >> On Wed, 3 Mar 2004 13:52:41 -0000, Keith Willshaw wrote:
    >>> "Earl Evleth" <[email protected]> wrote in message
    >>> news:BC6B9A86.28826%[email protected]...
    >>>> On 3/03/04 13:15, in article [email protected], "Keith
    >>>> Willshaw" <[email protected]> wrote:
    >>>>> Trouble as studies have shown it emits 10 times more
    >>>>> pollutants than the average western car
    >>>> Since there only are a couple running around, no big deal!
    >>>> Earl
    >>> In Germany perhaps but at the peak there were 120,000
    >>> of them on the roads of Budapest and the city council
    >>> estimated that taking just 2,000 off the roads reduced the
    >>> pollution load by 331,000 kg per year
    >>> Keith
    >> I think your figures ar a bit suspect.
    >
    > The figures came from the Hungarians
    >
    >> That makes 165kg / trabi / year.
    >> The 1995 average CO2 for cars in the EU was 186g/km.
    >> So assuming the average car does say 15000km year (just guessing what a
    >> trabi might do),it would produce : 186x15000/1000 = 2790kg CO2 per year.
    >> This would mean that a trabi would on avearage drive only 887km per year,
    >> OR only emmit 1/16th the pollution per km of an average car.
    >
    > They were looking at pollutants that cause immediate damage, specifically
    > particulates, unburned hydrocarbons and NOx which the Trabi produces
    > at 10 times the rate of modern western cars
    >
    > One Hungarian official described the Trabi as "a mobile chemical weapon that
    > ought
    > to be tabled at the Geneva talks on chemical weapons disarmament".
    >
    > CO2 while a greenhouse gas is not normally considered in the list
    > of pollutants in such surveys.
    >
    > Keith

Point taken. I couldn't find any NOx figures easily.

I suspect most of the pollutants are because of the ridiculous 2-stroke oil
they use. If they used a decent synthetic one for motorbikes, for example
the figures would be better.
Still, I think the biggest problem is the pollution caused when the car
bursts into flame when filling it up with petrol and you spill some on the
hot engine. The filler is under the bonnet right on top of the engine.

--
Tim.

If the human brain were simple enough that we could understand it, we would
be so simple that we couldn't.

Earl Evleth

On 4/03/04 9:15, in article
[email protected] , "Tim Challenger"
<"timothy(dot)challenger(at)apk(dot)at"> wrote:

    > I suspect most of the pollutants are because of the ridiculous 2-stroke oil
    > they use. If they used a decent synthetic one for motorbikes, for example
    > the figures would be better.


The 2CV used the same 2 stroke and I suspect that a number of motorized
bikes (not motorcycles) are still, outboards, snowmobiles?


My impression is that the 2-stroke engine designs had improved over the
recent years (the web says so but they are interested party postings).
Fuel injection avoids some of the older problems.

In fact, the auestion arises as to whether 2-strokes can be made
to function better than 4-strokes, what the possibly superiority
might be. The alternate consideration Is rotary engine designs?

Any people out there who know what the various pros and cons are?

One known advantage of electric motors is that the develop maximum
torque at zero RPM and that internal combustion engines have to
rev up a bit before reaching maximum torque.

Earl

Tim Challenger

On Thu, 04 Mar 2004 10:21:58 +0100, Earl Evleth wrote:

    > In fact, the auestion arises as to whether 2-strokes can be made
    > to function better than 4-strokes, what the possibly superiority
    > might be. The alternate consideration Is rotary engine designs?

If you can solve the lubrication problem (which is why 2-strokes have to
mix oil with the fuel) they can be pretty clean. There are some new
materials out that reduce the need to burn oil for lubrication.
Unfortunately they have a bad reputation which is difficult to shake off,
so little development is being made.

Compared to 4-strokes they are smaller, much lighter, much simpler (no
cams, chains, timing gears, no heavy valves and springs), and when running
well are very efficient and powerful for a given displacement. The downside
is they have a fairly narrow rev range at which they work efficiently.
There are numerous partial solutions to this problem, mostly involving
variable resonance-tuning in the exhaust/inlet systems to aid exhaust gas
scavenging. Eg The Yamaha YPVS and Aprilia power valve systems. Not totally
effective on the whole, but still an improvement.

I've heard about and seen documentaries about some major car makers
developing 2-strokes but I'm damned if I can find anything out about them.

A practical use would be in the hybrid cars, where the car runs on
electricity from a battery which is charged by petrol engine. A 2-stroke
would be free to work at its most efficient, charging the system.

--
Tim.

If the human brain were simple enough that we could understand it, we would
be so simple that we couldn't.

Keith Willshaw

"Earl Evleth" <[email protected]> wrote in message
news:BC6CB3C6.28A89%[email protected]...
    > On 4/03/04 9:15, in article
    > [email protected] , "Tim Challenger"
    > <"timothy(dot)challenger(at)apk(dot)at"> wrote:
    > > I suspect most of the pollutants are because of the ridiculous 2-stroke
oil
    > > they use. If they used a decent synthetic one for motorbikes, for
example
    > > the figures would be better.
    > The 2CV used the same 2 stroke and I suspect that a number of motorized
    > bikes (not motorcycles) are still, outboards, snowmobiles?

I dont think so, the 2CV's had a 2 cylinder air cooled engine
but ISTR it was a 4 stroke. The Wartburg had a 2 stroke engine
as did some early SAAB's

    > My impression is that the 2-stroke engine designs had improved over the
    > recent years (the web says so but they are interested party postings).
    > Fuel injection avoids some of the older problems.

2 strokes tend to produce more power for a given engine capacity
since they produce power every second dtroke and can be
simpler but they tend to be less efficient

    > In fact, the auestion arises as to whether 2-strokes can be made
    > to function better than 4-strokes, what the possibly superiority
    > might be. The alternate consideration Is rotary engine designs?

Rotary engine designs have their own problem with tip seals
but Mazda have made them work. Frankly modern 4 strokes
are pretty efficient.


    > Any people out there who know what the various pros and cons are?
    > One known advantage of electric motors is that the develop maximum
    > torque at zero RPM and that internal combustion engines have to
    > rev up a bit before reaching maximum torque.

The problem with electric motors is generating and storing the
power to drive them. The thermal efficiency of the typical
fossil fuelled power plant is around 30% which is BELOW
that of an efficient 4 stroke engine.

Keith

The Reid

Following up to Earl Evleth

    >Most drivers are not trained to drive at high speeds.

IMO training isn't the thing, if you need training then you
should steer clear of speed. Many are naturally technically
competent drivers after a bit of practice, what they need is
experience and maturity, luckily insurance costs keep the new
driver away from fast cars. The ""gripping the wheel, mouth open"
type of driver could never be "trained" to drive fast and the
need for experience on the part of the technically competent
driver is largely to be able to anticipate the actions of those
drivers, not to keep the car on the road.

    >Second, the least error and you have had it.

I think you may have an exagerrated idea of how difficult to
drive at high speed in the appropriate place. The driver you
mention drifting of the road onto the verge must have been either
asleep or totally incompetent. It *isnt* hard to control a
suitable car at say 130mph.
Are you sure most fatalities are from single car acidents?
--
Mike Reid
"Art is the lie that reveals the truth" P.Picasso
Walking, Wasdale, Thames path, London etc "http://www.fellwalk.co.uk" <-- you can email us@ this site
Spain, food and walking "http://www.fell-walker.co.uk" <-- dontuse@ all, it's a spamtrap

Tim Challenger

On Thu, 4 Mar 2004 09:44:33 -0000, Keith Willshaw wrote:

    > "Earl Evleth" <[email protected]> wrote in message
    > news:BC6CB3C6.28A89%[email protected]...
    >> On 4/03/04 9:15, in article
    >> [email protected] , "Tim Challenger"
    >> <"timothy(dot)challenger(at)apk(dot)at"> wrote:
    >>> I suspect most of the pollutants are because of the ridiculous 2-stroke
    > oil
    >>> they use. If they used a decent synthetic one for motorbikes, for
    > example
    >>> the figures would be better.
    >> The 2CV used the same 2 stroke and I suspect that a number of motorized
    >> bikes (not motorcycles) are still, outboards, snowmobiles?
    >
    > I dont think so, the 2CV's had a 2 cylinder air cooled engine
    > but ISTR it was a 4 stroke. The Wartburg had a 2 stroke engine
    > as did some early SAAB's
    >
    >> My impression is that the 2-stroke engine designs had improved over the
    >> recent years (the web says so but they are interested party postings).
    >> Fuel injection avoids some of the older problems.
    >
    > 2 strokes tend to produce more power for a given engine capacity
    > since they produce power every second dtroke and can be
    > simpler but they tend to be less efficient
    >
    >> In fact, the auestion arises as to whether 2-strokes can be made
    >> to function better than 4-strokes, what the possibly superiority
    >> might be. The alternate consideration Is rotary engine designs?
    >
    > Rotary engine designs have their own problem with tip seals
    > but Mazda have made them work. Frankly modern 4 strokes
    > are pretty efficient.
    >
    >> Any people out there who know what the various pros and cons are?
    >> One known advantage of electric motors is that the develop maximum
    >> torque at zero RPM and that internal combustion engines have to
    >> rev up a bit before reaching maximum torque.
    >
    > The problem with electric motors is generating and storing the
    > power to drive them. The thermal efficiency of the typical
    > fossil fuelled power plant is around 30% which is BELOW
    > that of an efficient 4 stroke engine.
    >
    > Keith

I think you're right. It has a 2-cylinder boxer engine.
--
Tim.

If the human brain were simple enough that we could understand it, we would
be so simple that we couldn't.

Earl Evleth

On 4/03/04 10:28, in article
[email protected] , "Tim Challenger"
<"timothy(dot)challenger(at)apk(dot)at"> wrote:

    > On Thu, 04 Mar 2004 10:21:58 +0100, Earl Evleth wrote:
    >
    >> In fact, the auestion arises as to whether 2-strokes can be made
    >> to function better than 4-strokes, what the possibly superiority
    >> might be. The alternate consideration Is rotary engine designs?
    >
    > If you can solve the lubrication problem (which is why 2-strokes have to
    > mix oil with the fuel) they can be pretty clean. There are some new
    > materials out that reduce the need to burn oil for lubrication.

That is where fuel injection comes in, this avoids the fuel mix.

    > Unfortunately they have a bad reputation which is difficult to shake off,
    > so little development is being made.

People are generally willing to accept new technology if the advantage
is net. For a small improvement, it is not worth the change over.

    > Compared to 4-strokes they are smaller, much lighter, much simpler (no
    > cams, chains, timing gears, no heavy valves and springs), and when running
    > well are very efficient and powerful for a given displacement.

In fact looking at all of this, 4 strokes appear unnecessarily complicated.
Remember the Rube Goldberg contraptions!


    > I've heard about and seen documentaries about some major car makers
    > developing 2-strokes but I'm damned if I can find anything out about them.

If you look at the long history of great technological advances as predicted
by Popular Mechanics or Popular Science you get the feeling that nothing
is predictable! Remember those futuristic predictions of everybody
flying to work in their helicopter, circa 1948!

Earl

Earl Evleth

On 4/03/04 10:44, in article [email protected], "Keith
Willshaw" <[email protected]> wrote:

    > The problem with electric motors is generating and storing the
    > power to drive them. The thermal efficiency of the typical
    > fossil fuelled power plant is around 30% which is BELOW
    > that of an efficient 4 stroke engine.


First, are you sure of that figure?

1) My memory is that the Carnot efficiency of the auto gasoline engine was
about 25%, Diesel higher since they run hotter.

for example on the web one will quickly run into by googling
"carnot efficiencies".

"Thermal Efficiencies of Common Devices. Spark ignition engines : 25-30 %;
Diesel engines : 35-40%; Power plants: 40-60%."

2) Thermal power generation plants running with super heated steam
technology, I thought, had up to 40% Carnot efficiencies (I don`t
remember anything as high as 60%!)

Nuclear power plants are the 25% converters since one has a lower
limit on the temperature of the reactor.

3) The idea of the electric motor, eventually, would be to run
off fuel cells, which escape the thermodyanmic trap of heat engines.
Over all chemical to electrical energy conversions should reach the
practical level of 80%. The electric motor, I believe, has a
about a 90% efficiency for electrical => mechanical energy conversion?

The problem is, of course "the fuel cell", what fuel cell? The hydrogen
economy proposition has it own set of problems, I would not like to
fool around with stored (in whatever form) hydrogen gas. One proposition
is to go over to a methanol economy, using it as the carrier, for which,
I understand, there exists now a good fuel cell.

Earl

Tim Challenger

On Thu, 04 Mar 2004 12:22:12 +0100, Earl Evleth wrote:

    > That is where fuel injection comes in, this avoids the fuel mix.

Not at all. It's got nothing to do with fuel injection whatsoever.

The oil mix in 2-strokes provides the lubrication for the cylinder/piston.
This is provided by the normal engine oil in a 4-stroke - squirted up
underneath the piston on each stroke. Where the oil can lubricate and cool
the cylinder and piston rings.
You can't do this on a 2-stroke as the piston is longer and acts as the
valve-timing mechanism. So the oil can't physically get to the place where
the piston-rings are = no lubrication = seized engine in a very short time.

The oil has to get to the piston rings one way or another. From below is
out, that only leaves the top, via the combustion chamber. That's why the
oil is currently put into the fuel either as a pre-mix (from the petrol
pumps in many fuel stations) or from a seperate oil tank which is mixed
into the fuel near the carbs.

I'm sure it would be feasable to inject the fuel and oil either together
or, better, seperately into the combustion chamber.

    >> Unfortunately they have a bad reputation which is difficult to shake off,
    >> so little development is being made.

    >People are generally willing to accept new technology if the advantage
    >is net. For a small improvement, it is not worth the change over.

How true.
Still, I think Toyota, Peugeot and Renault are all working on new 2-strokes
for petrol and diesel fuels.

    >In fact looking at all of this, 4 strokes appear unnecessarily complicated.

They are. Take a 4-stroke and remove ALL the stuff needed for any valve
timing: that's the whole top end- valves, cam shafts, springs, timing
chains, chain adjusters. Replace that with a couple of reed-valves (not
unlike the reed in a wind-instrument) which weigh a couple of ounces at
most. Quite a weight and complexity saving.
On the up-side, 4-strokes do have the advantage of a wider power spread and
more torque. Plus they are cleaner at the moment (want to count the amount
of money spent on getting 4-stroke engines cleaner over the years?)

--
Tim.

If the human brain were simple enough that we could understand it, we would
be so simple that we couldn't.

Tim Challenger

On Thu, 04 Mar 2004 12:41:11 +0100, Earl Evleth wrote:

    >> The problem with electric motors is generating and storing the
    >> power to drive them. The thermal efficiency of the typical
    >> fossil fuelled power plant is around 30% which is BELOW
    >> that of an efficient 4 stroke engine.

I think figure this takes into account losses across the grid as well. By
the time the electricity has actually got to the consumer the original 60%
odd has dropped considerably.
--
Tim.

If the human brain were simple enough that we could understand it, we would
be so simple that we couldn't.

Keith Willshaw

"Earl Evleth" <[email protected]> wrote in message
news:BC6CD467.28B0F%[email protected]...
    > On 4/03/04 10:44, in article [email protected], "Keith
    > Willshaw" <[email protected]> wrote:
    > > The problem with electric motors is generating and storing the
    > > power to drive them. The thermal efficiency of the typical
    > > fossil fuelled power plant is around 30% which is BELOW
    > > that of an efficient 4 stroke engine.
    > First, are you sure of that figure?

Yep

    > 1) My memory is that the Carnot efficiency of the auto gasoline engine was
    > about 25%, Diesel higher since they run hotter.
    > for example on the web one will quickly run into by googling
    > "carnot efficiencies".
    > "Thermal Efficiencies of Common Devices. Spark ignition engines : 25-30 %;
    > Diesel engines : 35-40%; Power plants: 40-60%."
    > 2) Thermal power generation plants running with super heated steam
    > technology, I thought, had up to 40% Carnot efficiencies (I don`t
    > remember anything as high as 60%!)

The Carnot efficiency is the upper limit of heat engine efficiency
based on operating temperatures. For Steam plants its usually measured
by calculating the heat contained in the steam at input and comparing
it with the work done by the turbine. It doesnt take into account losses
in the boiler or transmission and distribution.

What you need to measure is what is the ratio between energy
released in combustion of the fuel and the energy delivered
at the power socket. This is termed the electrical efficiency and
is typically in the range 14-35%. The VERY best figure I have
seen was produced by the German Scwarze Pumpe power plant
near Dresden which when new operated at 41% electrical efficiency
at point of distribution

For a modern gas turbine power plant the figure is typically in the
30-35% range at full power

Diesel engines are typically around 35-45% with spark ignition
engines 27-40%

If you have a combined heat and power system then the
thermal efficiency of the system can be much higher
as the heat that a power utility disperses into the
atmosphere via the cooling tower can be usefully used

    > Nuclear power plants are the 25% converters since one has a lower
    > limit on the temperature of the reactor.
    > 3) The idea of the electric motor, eventually, would be to run
    > off fuel cells, which escape the thermodyanmic trap of heat engines.

Not really. You need to produce, store and distribute the H2
used by the fuel cells and that is typically done by the steam reforming
of natural gas (a process producing LARGE amounts of CO2) or
electrloysis.

This turns out to be LESS efficient than using the natural gas
to drive closed cycle gas turbines.

    > Over all chemical to electrical energy conversions should reach the
    > practical level of 80%.

No Mam. The electrical efficiency of most fuel cells is closer
to 45% due to losses in fuel reformer, the cell stack, the inverter
and the auxiliary equipment. There are some new designs using
micro-turbine/fuel cell systems that approach 60%

Essentially natural gas is used in the fuelcell and the exhaust drives
a small gas turbine. The main problem at present is the high
capital cost of the system compared with conventional closed
cycle gas turbine plant

    > The electric motor, I believe, has a
    > about a 90% efficiency for electrical => mechanical energy conversion?

Indeed but first you have to produce and store the electricity

    > The problem is, of course "the fuel cell", what fuel cell? The hydrogen
    > economy proposition has it own set of problems, I would not like to
    > fool around with stored (in whatever form) hydrogen gas. One proposition
    > is to go over to a methanol economy, using it as the carrier, for which,
    > I understand, there exists now a good fuel cell.

Methanol of course is also an excellent fuel for conventional
spark ignition engines but you must first produce your methanol
which has its own problems.

Keith