Car Alternator as Human Powered Generator

On 28 May 2004 23:14:56 -0700, Robin@HimalayanHandicraft.org (Robin)
wrote:

Hello All,

I do some volunteer work that provides rural villagers in Nepal with
WiFi communication (See http://NepalWireless.net if you are
interested). As part of this work, we need to develop a human powered
generator to charge our solar batteries when there is no sun for
months on end. Is a car alternator and a bicycle a possibility? How
much current/voltage does a typical alternator produce and what RPM is
necessary? These are both readily available in Nepal, so they would
be idea. Thanks very much.

Robin Shields
Click to expand...
I'd guess that a car alternator would be serious overkill... too much
windage and bearing loss, and even the field excitation would exhaust
the peddler pretty quick. A smaller permanent-magnet motor would
probably be a better match at this power level. Maybe


A motorcycle generator (PM rotating field)

An auto window-winder motor. New ones are super-magnet field things

A PM stepper motor, maybe from an old printer. Maybe several.


John
 
X-No-Archive: yes
"Robin" <Robin@HimalayanHandicraft.org> wrote in message
news:af190b62.0405282214.1c145968@posting.google.com...
: Hello All,
:
: I do some volunteer work that provides rural villagers in
Nepal with
: WiFi communication (See http://NepalWireless.net if you are
: interested). As part of this work, we need to develop a human
powered
: generator to charge our solar batteries when there is no sun for
: months on end. Is a car alternator and a bicycle a possibility?
How
: much current/voltage does a typical alternator produce and what
RPM is
: necessary? These are both readily available in Nepal, so they
would
: be idea. Thanks very much.
:
: Robin Shields

Nepal produces 81% of it's electricity from Hydro. Why not use it?
Why go to all the trouble of manually generating a few watts to
power a WiFi terminal?

Also when the sun doesn't shine, Monsoon rains are pouring down,
funnel it into a small hydro generator for recharging the
batteries.
 
Jim Thompson <thegreatone@example.com> wrote in
news:me8ib0ps5kigjlm4gk89g2o1usbq11pahg@4ax.com:

On Sat, 29 May 2004 22:50:22 -0000, "Rich.Andrews" <spmaway@ylhoo.com
wrote:

Robin@HimalayanHandicraft.org (Robin) wrote in
news:af190b62.0405282214.1c145968@posting.google.com:

Hello All,

I do some volunteer work that provides rural villagers in Nepal with
WiFi communication (See http://NepalWireless.net if you are
interested). As part of this work, we need to develop a human powered
generator to charge our solar batteries when there is no sun for
months on end. Is a car alternator and a bicycle a possibility? How
much current/voltage does a typical alternator produce and what RPM is
necessary? These are both readily available in Nepal, so they would
be idea. Thanks very much.

Robin Shields


It takes a fair amount of power to run an alternator at full output. If
you take a 50 amp alternator, ground the output and fully energize the
rotor coil, ir will stall out a large 6 cylinder Cummins diesel engine.
As a matter of fact it will stall it out so quickly, that a bystander
would say that you shut the engine off.

r


Where in the world did you get that idea? Must be some weenie engine!

12V at 50A is only 600W, even presuming something like 50% efficiency
that's only 1.6hp.

IIRC a typical automotive 50A alternator takes about 6hp input at
(alternator) 14,000RPM.

...Jim Thompson
Click to expand...

Jim,

As unbelievable as it sounds, my boss told me this when I was working as a
truck and heavy equiment mechanic. The next time I had an opportunity, I
tried it on a CCC (Crane Carrier Co.) truck. This was a older version of
the Redi-Mix truck pictured at http://www.cranecarrier.com/specialty.htm
and as a matter of fact it was very close to the one pictured at
http://www.cranecarrier.com/images/hist_picture_015.jpg

Anyway, the truck featured a Cummins 6 cylinder diesel engine similar to
the GMC 671 series diesel engine. It had similar displacement, (about 71
cu inches per cylinder), and 6 cylinders. Of course the Cummins did not
have a supercharger like the GMC, but since the GMC is a 2 cycle diesel,
it has to have a supercharger. Anyway the engine was idling and when I
applied 12 volts to the rotor of the alternator with it's output shunted
directly to ground, the engine stalled and stopped almost as if one had
shut off the fuel. Yes, the fuel shutoff valve was bypassed just to make
sure there was no doubt that this was NOT a rigged demo.

If you want another unbelieveable true story, let me tell you about the
time I fired up a GMC engine in a International truck and it started
running backwards. Smoke was pouring out the intake and it lacked all
manner of power. Reverse was forward and forward gear was reverse. Once
I figured out what was going on, I shut it off, restarted and everything
was fine.

r





--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.
 
Roger Gt wrote:
X-No-Archive: yes
"Robin" <Robin@HimalayanHandicraft.org> wrote in message
news:af190b62.0405282214.1c145968@posting.google.com...
: Hello All,
:
: I do some volunteer work that provides rural villagers in
Nepal with
: WiFi communication (See http://NepalWireless.net if you are
: interested). As part of this work, we need to develop a human
powered
: generator to charge our solar batteries when there is no sun for
: months on end. Is a car alternator and a bicycle a possibility?
How
: much current/voltage does a typical alternator produce and what
RPM is
: necessary? These are both readily available in Nepal, so they
would
: be idea. Thanks very much.
:
: Robin Shields

Nepal produces 81% of it's electricity from Hydro. Why not use it?
Why go to all the trouble of manually generating a few watts to
power a WiFi terminal?
------------------
Click to expand...
No power distribution wiring.


Also when the sun doesn't shine, Monsoon rains are pouring down,
funnel it into a small hydro generator for recharging the
batteries.
--------------------
Click to expand...
Not bad, but it would take a lake. Not portable.

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
Rich.Andrews wrote:
Anyway, the truck featured a Cummins 6 cylinder diesel engine similar to
the GMC 671 series diesel engine. It had similar displacement, (about 71
cu inches per cylinder), and 6 cylinders. Of course the Cummins did not
have a supercharger like the GMC, but since the GMC is a 2 cycle diesel,
it has to have a supercharger. Anyway the engine was idling and when I
applied 12 volts to the rotor of the alternator with it's output shunted
directly to ground, the engine stalled and stopped almost as if one had
shut off the fuel. Yes, the fuel shutoff valve was bypassed just to make
sure there was no doubt that this was NOT a rigged demo.
--------------------
Click to expand...
Why is this surprising?? You just invented an electric brake!


If you want another unbelieveable true story, let me tell you about the
time I fired up a GMC engine in a International truck and it started
running backwards. Smoke was pouring out the intake and it lacked all
manner of power. Reverse was forward and forward gear was reverse. Once
I figured out what was going on, I shut it off, restarted and everything
was fine.

r
-------------------
Click to expand...
How was it running backwards? The 4-stroke cycle doesn't permit this!
Sounds like an urban legend. Do you mean the starter turned it
backwards, why was the bettery reversed?

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
"Robin" <Robin@HimalayanHandicraft.org> wrote in message
news:af190b62.0405282214.1c145968@posting.google.com...
Hello All,

I do some volunteer work that provides rural villagers in Nepal with
WiFi communication (See http://NepalWireless.net if you are
interested). As part of this work, we need to develop a human powered
generator to charge our solar batteries when there is no sun for
months on end. Is a car alternator and a bicycle a possibility? How
much current/voltage does a typical alternator produce and what RPM is
necessary? These are both readily available in Nepal, so they would
be idea. Thanks very much.

Robin Shields
Click to expand...
A *smaller* PM dc motor linked to a metal gearbox and a handcrank is the
way to go. I recently tried this as a method of recharging NiMH batteries
for my shortwave portable. My gearbox had plastic gears though, and they
only lasted about 30 seconds before succumbing to the stress I was putting
on them (which was backwards for the way they were designed to be used. I
was using the big gear to drive the small gear, not the other way round.)
For that 30 seconds though, it put out 500 mW at nearly 9V. Now if I just
get off my butt and find some metal gears that fit that housing, I'll be
set. If you are trying to charge a big battery, crank it for a longer
period of time (or with several volunteers in succession.) A better idea
would be to hook it up to a bicycle, since the muscles in the legs are more
suited to this type of thing. That would be less portable though (which was
one of my major concerns.)

Dave
db5151@hotmail.com
 
"Roger Gt" <not@here.net> wrote in message
news:AB7uc.74547$Uk1.35084@newssvr25.news.prodigy.com...
X-No-Archive: yes
A prime example of true British Thinking!
Cubic meters? How about cubic "cubits?"
Click to expand...
That one went over my head
 
"Rich.Andrews" <spmaway@ylhoo.com> wrote in message
news:Xns94F8DE487581Cmc2500183316chgoill@10.232.1.1...
Jim Thompson <thegreatone@example.com> wrote in
news:me8ib0ps5kigjlm4gk89g2o1usbq11pahg@4ax.com:

On Sat, 29 May 2004 22:50:22 -0000, "Rich.Andrews" <spmaway@ylhoo.com
wrote:

Robin@HimalayanHandicraft.org (Robin) wrote in
news:af190b62.0405282214.1c145968@posting.google.com:

Hello All,

I do some volunteer work that provides rural villagers in Nepal with
WiFi communication (See http://NepalWireless.net if you are
interested). As part of this work, we need to develop a human powered
generator to charge our solar batteries when there is no sun for
months on end. Is a car alternator and a bicycle a possibility? How
much current/voltage does a typical alternator produce and what RPM is
necessary? These are both readily available in Nepal, so they would
be idea. Thanks very much.

Robin Shields


It takes a fair amount of power to run an alternator at full output. If
you take a 50 amp alternator, ground the output and fully energize the
rotor coil, ir will stall out a large 6 cylinder Cummins diesel engine.
As a matter of fact it will stall it out so quickly, that a bystander
would say that you shut the engine off.

r


Where in the world did you get that idea? Must be some weenie engine!

12V at 50A is only 600W, even presuming something like 50% efficiency
that's only 1.6hp.

IIRC a typical automotive 50A alternator takes about 6hp input at
(alternator) 14,000RPM.

...Jim Thompson


Jim,

As unbelievable as it sounds, my boss told me this when I was working as a
truck and heavy equiment mechanic. The next time I had an opportunity, I
tried it on a CCC (Crane Carrier Co.) truck. This was a older version of
the Redi-Mix truck pictured at http://www.cranecarrier.com/specialty.htm
and as a matter of fact it was very close to the one pictured at
http://www.cranecarrier.com/images/hist_picture_015.jpg

Anyway, the truck featured a Cummins 6 cylinder diesel engine similar to
the GMC 671 series diesel engine. It had similar displacement, (about 71
cu inches per cylinder), and 6 cylinders. Of course the Cummins did not
have a supercharger like the GMC, but since the GMC is a 2 cycle diesel,
it has to have a supercharger. Anyway the engine was idling and when I
applied 12 volts to the rotor of the alternator with it's output shunted
directly to ground, the engine stalled and stopped almost as if one had
shut off the fuel. Yes, the fuel shutoff valve was bypassed just to make
sure there was no doubt that this was NOT a rigged demo.

If you want another unbelieveable true story, let me tell you about the
time I fired up a GMC engine in a International truck and it started
running backwards. Smoke was pouring out the intake and it lacked all
manner of power. Reverse was forward and forward gear was reverse. Once
I figured out what was going on, I shut it off, restarted and everything
was fine.
Click to expand...
This happened to a friend of mine on a two stroke diesel after a
particularly poor gear change on a steep hill. He doubled the cluth into
first gear and when he let the clutch up the wagon went backwards. To make
matters worse the air intake was in the engine compartment between the
seats, within a second or two the cab was completely full of smoke. It's a
good 20 years ago or so.
 
X-No-Archive: yes
"Mjolinor" wrote
: "Roger Gt" wrote
: > A prime example of true British Thinking!
: > Cubic meters? How about cubic "cubits?"
:
: That one went over my head


A Cubit is about 18 inches, so a cubic Cubit would be about a
quarter the volume of a cubic meter. (See conversions) Not
likely a single ox would produce a large volume of Methane gas
what you could meter in cu Meters!

Looses a lot in translation!
 
"Roger Gt" <not@here.net> wrote in message
news:hYguc.1892$vj7.514@newssvr27.news.prodigy.com...
X-No-Archive: yes
"Mjolinor" wrote
: "Roger Gt" wrote
: > A prime example of true British Thinking!
: > Cubic meters? How about cubic "cubits?"
:
: That one went over my head


A Cubit is about 18 inches, so a cubic Cubit would be about a
quarter the volume of a cubic meter. (See conversions) Not
likely a single ox would produce a large volume of Methane gas
what you could meter in cu Meters!

Looses a lot in translation!
Click to expand...
It certainly does because that one went over my head as well.

I would have thought that as it was cubic metres initially then it would be
more correct to quote a cubit to be slightly over 457 mm. I suspect the
volume would be the same whether measured in cubic metres or cubic cubits or
maybe some other antiquated units like cubic inches, cubic feet or maybe
cubic furlongs is to your taste. :)

Using the manure as well you get the equivalent to about 50 gallons of
petrol per year in methane from one cow. The gaseous emmisions will light a
75 watt light bulb continuously. If the Internet is to be believed :)
 
"R. Steve Walz" <rstevew@armory.com> wrote in
news:40B968B1.55B9@armory.com:

Rich.Andrews wrote:

Anyway, the truck featured a Cummins 6 cylinder diesel engine similar
to the GMC 671 series diesel engine. It had similar displacement,
(about 71 cu inches per cylinder), and 6 cylinders. Of course the
Cummins did not have a supercharger like the GMC, but since the GMC is
a 2 cycle diesel, it has to have a supercharger. Anyway the engine was
idling and when I applied 12 volts to the rotor of the alternator with
it's output shunted directly to ground, the engine stalled and stopped
almost as if one had shut off the fuel. Yes, the fuel shutoff valve
was bypassed just to make sure there was no doubt that this was NOT a
rigged demo.
--------------------
Why is this surprising?? You just invented an electric brake!


If you want another unbelieveable true story, let me tell you about the
time I fired up a GMC engine in a International truck and it started
running backwards. Smoke was pouring out the intake and it lacked all
manner of power. Reverse was forward and forward gear was reverse.
Once I figured out what was going on, I shut it off, restarted and
everything was fine.

r
-------------------
How was it running backwards? The 4-stroke cycle doesn't permit this!
Sounds like an urban legend. Do you mean the starter turned it
backwards, why was the bettery reversed?

-Steve
Click to expand...
It is not an urban legend. I was there. I started it, I tried to drive
it. The year was circa 1975. It was a cold day with snow on the ground.
The foremans last name was Fang. Had efficiency experts come there once.
They worked for a company called Proudfoot. No urban legend here.

All of the GMC engines that I have ever worked with are 2 cycle engines.
That includes their very large locomotive and marine engines. (Yes I
worked for Electro-motive for a while as a Locomotive Electrician) That
also includes their 53 series engine which boasts 53 cubic inches
displacement per cylinder. That little workhorse is pretty amazing. That
particular engine was used in a piece of equiment commonly called a
Straddle-Buggy. Made by Hi-Jack? Corp who has offices in Hazel Crest IL.
The tires used on that bit of equiment were used commercial aircraft
tires. I digress, but GM's supercharged and turbocharged (yes, both at
once) 6 and 8 cylinder models are rather special too.

The engine in question was a GMC engine. A series 871 if memory serves me
right. If it wasn't a 871 it was a 671. (we had 1671 series as well..16
cylinders at 71 cubic inches per cylinder. See Euclid R-50.) What
happened was that the starter was not engaged for the proper length of
time and the resultant "kickback" had enough energy to start the engine
rotating and firing backwards. This mode of operation is not recommended
due to the lack of oil pressure. Yes, I noticed that there was no oil
pressure on the gauge, but since so many things didn't work when it was
unknowingly run backwards, I figured that is why it was brought to the
shop. It wasn't until I tried to move it and the vehicle travelled the
opposite direction of what was clearly marked on the transmission shift
pattern plate, that I realized what had happened. That was a few careers
ago. Many things have changed since then.


r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.
 
"Jim Thompson" <thegreatone@example.com> wrote in message
news:me8ib0ps5kigjlm4gk89g2o1usbq11pahg@4ax.com...

Where in the world did you get that idea? Must be some weenie engine!

12V at 50A is only 600W, even presuming something like 50% efficiency
that's only 1.6hp.
Click to expand...
Thats lots more than a human can produce though.
 
On Sun, 30 May 2004 04:45:22 GMT, R. Steve Walz <rstevew@armory.com> wrote:

Also when the sun doesn't shine, Monsoon rains are pouring down,
funnel it into a small hydro generator for recharging the
batteries.
--------------------
Not bad, but it would take a lake. Not portable.
Click to expand...
True about the not being portable but micro hydro will work on runoff.
(works here. in winter)

Still, a major installation compared to a bicycle. and definitely not "on
demand"

Fritz
 
X-No-Archive: yes

"Mjolinor" wrote
: "Roger Gt" wrote
: > "Mjolinor" wrote
: > : "Roger Gt" wrote

: > : > "A prime example of true British Thinking!"

: > : > Cubic meters? How about cubic "cubits?"
: > : That one went over my head
: > A Cubit is about 18 inches, so a cubic Cubit would be about a
: > quarter the volume of a cubic meter. (See conversions) Not
: > likely a single ox would produce a large volume of Methane gas
: > what you could meter in cu Meters!
: >
: > Looses a lot in translation!
:
: It certainly does because that one went over my head as well.
:
: I would have thought that as it was cubic meters initially then
it would be
: more correct to quote a cubit to be slightly over 457 mm. I
suspect the
: volume would be the same whether measured in cubic meters or
cubic cubits or
: maybe some other antiquated units like cubic inches, cubic feet
or maybe
: cubic furlongs is to your taste. :)

A meter is 39.3700787 inch so 18 about inches is close enough for
government work!
Cubic Chains "Or" Fathoms, I use them all! They are all valid.
Like "Stones" in England!

: Using the manure as well you get the equivalent to about 50
gallons of
: petrol per year in methane from one cow. The gaseous emissions
will light a
: 75 watt light bulb continuously. If the Internet is to be
believed :)
:

The point was that the "British Thinking" is over stated in grand
terms and about manure!

I see that implied humor does not play well on the news group
unless you add :)>) to every instance! So the reader knows to
expect some obscure humor or innuendo!
 
On 28 May 2004 23:14:56 -0700, Robin wrote:

Hello All,

I do some volunteer work that provides rural villagers in Nepal with
WiFi communication (See http://NepalWireless.net if you are
interested). As part of this work, we need to develop a human powered
generator to charge our solar batteries when there is no sun for
months on end. Is a car alternator and a bicycle a possibility? How
much current/voltage does a typical alternator produce and what RPM is
necessary? These are both readily available in Nepal, so they would
be idea. Thanks very much.
Click to expand...
Quite possible, in fact, I saw one today in an environmental education site.
They had an older DC-generator resting with a small pully on the back wheel
tire, plus what looked like a much smaller generator a little bit behind
(maybe for the field current?). Very modest peddling already lighted a 20W
energy-savings lamp (small fluorescent), fanatical peddling lighted a 500W
halogen builder's lamp. A trained cyclist surely could supply 50W for a hour
at least. And I think a modern AC generator has higher efficiency, plus
voltage regulation built-in. The bicycle wheel was 24 inches maximum (might
have been smaller), the pully on the generator shaft looked like made from
brass about 4 cm diameter. The tire was slightly soft (not hard inflated).
Is there enough wind there to build a small windgenerator with it as well?
Maybe you can build it so that the generator can be used for both.

Mat Nieuwenhoven
 
"Roger Gt" <not@here.net> wrote in message
news:Wqouc.61478$zs5.40736@newssvr29.news.prodigy.com...
X-No-Archive: yes

"Mjolinor" wrote
: "Roger Gt" wrote
: > "Mjolinor" wrote
: > : "Roger Gt" wrote

: > : > "A prime example of true British Thinking!"

: > : > Cubic meters? How about cubic "cubits?"
: > : That one went over my head
: > A Cubit is about 18 inches, so a cubic Cubit would be about a
: > quarter the volume of a cubic meter. (See conversions) Not
: > likely a single ox would produce a large volume of Methane gas
: > what you could meter in cu Meters!
:
: > Looses a lot in translation!
:
: It certainly does because that one went over my head as well.
:
: I would have thought that as it was cubic meters initially then
it would be
: more correct to quote a cubit to be slightly over 457 mm. I
suspect the
: volume would be the same whether measured in cubic meters or
cubic cubits or
: maybe some other antiquated units like cubic inches, cubic feet
or maybe
: cubic furlongs is to your taste. :)

A meter is 39.3700787 inch so 18 about inches is close enough for
government work!
Cubic Chains "Or" Fathoms, I use them all! They are all valid.
Like "Stones" in England!

: Using the manure as well you get the equivalent to about 50
gallons of
: petrol per year in methane from one cow. The gaseous emissions
will light a
: 75 watt light bulb continuously. If the Internet is to be
believed :)
:

The point was that the "British Thinking" is over stated in grand
terms and about manure!
Click to expand...
I still don't see it :)

I see that implied humor does not play well on the news group
unless you add :)>) to every instance! So the reader knows to
expect some obscure humor or innuendo!
Click to expand...
Implied humour worked fine for me in all the posts.

As a user of "stones" I find it kind of hard to measure volume with it.
 
ROFLMAO!!!

Mjolinor wrote:

"Roger Gt" <not@here.net> wrote in message
news:hYguc.1892$vj7.514@newssvr27.news.prodigy.com...

X-No-Archive: yes
"Mjolinor" wrote
: "Roger Gt" wrote
: > A prime example of true British Thinking!
: > Cubic meters? How about cubic "cubits?"
:
: That one went over my head


A Cubit is about 18 inches, so a cubic Cubit would be about a
quarter the volume of a cubic meter. (See conversions) Not
likely a single ox would produce a large volume of Methane gas
what you could meter in cu Meters!

Looses a lot in translation!




It certainly does because that one went over my head as well.

I would have thought that as it was cubic metres initially then it would be
more correct to quote a cubit to be slightly over 457 mm. I suspect the
volume would be the same whether measured in cubic metres or cubic cubits or
maybe some other antiquated units like cubic inches, cubic feet or maybe
cubic furlongs is to your taste. :)

Using the manure as well you get the equivalent to about 50 gallons of
petrol per year in methane from one cow. The gaseous emmisions will light a
75 watt light bulb continuously. If the Internet is to be believed :)
Click to expand...
 
"Mat Nieuwenhoven" <mnieuw@dontincludethis.zap.a2000.nl> wrote in message
news:zavrhjqbagvapyhqrguvfmncnay.hyjrp51.pminews@news.text.chello.nl...
On 28 May 2004 23:14:56 -0700, Robin wrote:

Hello All,

I do some volunteer work that provides rural villagers in Nepal with
WiFi communication (See http://NepalWireless.net if you are
interested). As part of this work, we need to develop a human powered
generator to charge our solar batteries when there is no sun for
months on end. Is a car alternator and a bicycle a possibility? How
much current/voltage does a typical alternator produce and what RPM is
necessary? These are both readily available in Nepal, so they would
be idea. Thanks very much.

Quite possible, in fact, I saw one today in an environmental education
site.
They had an older DC-generator resting with a small pully on the back
wheel
tire, plus what looked like a much smaller generator a little bit behind
(maybe for the field current?). Very modest peddling already lighted a
20W
energy-savings lamp (small fluorescent), fanatical peddling lighted a 500W
halogen builder's lamp. A trained cyclist surely could supply 50W for a
hour
at least. And I think a modern AC generator has higher efficiency, plus
voltage regulation built-in. The bicycle wheel was 24 inches maximum
(might
have been smaller), the pully on the generator shaft looked like made from
brass about 4 cm diameter. The tire was slightly soft (not hard inflated).
Is there enough wind there to build a small windgenerator with it as well?
Maybe you can build it so that the generator can be used for both.

Mat Nieuwenhoven
Click to expand...
There has been much noise and warm air about micro generation techniques.
Little useful will come from this speculation before the OP states what kind
of load and duty cycle he needs. Once he defines his needs, then he might
also disclose his assets; available money & labor & time, geography, local
fuel assets and local weather. Even local social customs may be a huge
factor; for instance, possibly one of those Sherpa guys, who can climb to
20k feet without breathing heavy, might be able to put out prodgious power
from a bicycle generator at 8k feet. OTOH, he may be prevented from doing
this by viewing this as a less than honorable task for a Sherpa man.

Ed
 
Roger Gt wrote:
X-No-Archive: yes
"Mjolinor" wrote
: "Roger Gt" wrote
: > A prime example of true British Thinking!
: > Cubic meters? How about cubic "cubits?"
:
: That one went over my head

A Cubit is about 18 inches, so a cubic Cubit would be about a
quarter the volume of a cubic meter.
-----------
Click to expand...
You mean an eighth.

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
Rich.Andrews wrote:
"R. Steve Walz" <rstevew@armory.com> wrote in
news:40B968B1.55B9@armory.com:

Rich.Andrews wrote:

Anyway, the truck featured a Cummins 6 cylinder diesel engine similar
to the GMC 671 series diesel engine. It had similar displacement,
(about 71 cu inches per cylinder), and 6 cylinders. Of course the
Cummins did not have a supercharger like the GMC, but since the GMC is
a 2 cycle diesel, it has to have a supercharger. Anyway the engine was
idling and when I applied 12 volts to the rotor of the alternator with
it's output shunted directly to ground, the engine stalled and stopped
almost as if one had shut off the fuel. Yes, the fuel shutoff valve
was bypassed just to make sure there was no doubt that this was NOT a
rigged demo.
--------------------
Why is this surprising?? You just invented an electric brake!


If you want another unbelieveable true story, let me tell you about the
time I fired up a GMC engine in a International truck and it started
running backwards. Smoke was pouring out the intake and it lacked all
manner of power. Reverse was forward and forward gear was reverse.
Once I figured out what was going on, I shut it off, restarted and
everything was fine.

r
-------------------
How was it running backwards? The 4-stroke cycle doesn't permit this!
Sounds like an urban legend. Do you mean the starter turned it
backwards, why was the bettery reversed?

-Steve

It is not an urban legend. I was there. I started it, I tried to drive
it. The year was circa 1975. It was a cold day with snow on the ground.
The foremans last name was Fang. Had efficiency experts come there once.
They worked for a company called Proudfoot. No urban legend here.

All of the GMC engines that I have ever worked with are 2 cycle engines.
That includes their very large locomotive and marine engines. (Yes I
worked for Electro-motive for a while as a Locomotive Electrician) That
also includes their 53 series engine which boasts 53 cubic inches
displacement per cylinder. That little workhorse is pretty amazing. That
particular engine was used in a piece of equiment commonly called a
Straddle-Buggy. Made by Hi-Jack? Corp who has offices in Hazel Crest IL.
The tires used on that bit of equiment were used commercial aircraft
tires. I digress, but GM's supercharged and turbocharged (yes, both at
once) 6 and 8 cylinder models are rather special too.

The engine in question was a GMC engine. A series 871 if memory serves me
right. If it wasn't a 871 it was a 671. (we had 1671 series as well..16
cylinders at 71 cubic inches per cylinder. See Euclid R-50.) What
happened was that the starter was not engaged for the proper length of
time and the resultant "kickback" had enough energy to start the engine
rotating and firing backwards. This mode of operation is not recommended
due to the lack of oil pressure. Yes, I noticed that there was no oil
pressure on the gauge, but since so many things didn't work when it was
unknowingly run backwards, I figured that is why it was brought to the
shop. It wasn't until I tried to move it and the vehicle travelled the
opposite direction of what was clearly marked on the transmission shift
pattern plate, that I realized what had happened. That was a few careers
ago. Many things have changed since then.
------------------
Click to expand...
How does that occur even with the 2-stroke cycle, doesn't it require
that leave valves run backasswards? Or what kind of valve is that
silly thing, is this like those Detroit's that are 2-stroke?

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
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