It's expensive to refuel ($3,000) but since the range is around 4,200km
they're getting 1.4km to the dollar (close to a dollar per mile). Still
about 10 times worse than gas prices in the US assuming $2/gallon and 20mpg.
I imagine that the energy costs of the circuitry and sensors is far
greater than the propulsion. Using a much lower power system they could
probably double (or better) the range. Still cheaper than hiring a boat
and crew to do measurements for those same 4,000 km.
>Hi Guys
>Though that this would be interesting...
>
>http://spray.ucsd.edu/
>
>
>If anybody has any more info please let me know, I think this is just
>brilliant.
>Regards
> Luis
>
> (close to a dollar per mile). Still about 10 times worse than gas
> prices
> in the US assuming $2/gallon and 20mpg.
I didn't think boats got anywhere near 20mpg... Lots more drag than
cars,
and a less efficient propulsion scheme than wheels... (of course, this
is
just a "probe" sort of thing, so it might do better. But I dunno if
they
can even DO gasoline motors for that sort of craft...)
Boats usually measure fuel consumption in litres per hour or gallons per hour,
but I'd imagine, in a straight line over the ground, a boat engine would
consume more fuel than the car would to make the same journey.
I was in a museum a few weeks ago and saw a WWII torpedo that had a small 100-200 CC 4 cylinder radial 4 stroke gas motor complete with a compressed air tank for running under water. (Its in Halifax NS if anyone is interested) It is a credit to the guy
who created it.
> On Nov 19, 2004, at 6:48 AM, M. Adam Davis wrote:
>
> > (close to a dollar per mile). Still about 10 times worse than gas
> > prices
> > in the US assuming $2/gallon and 20mpg.
>
> I didn't think boats got anywhere near 20mpg... Lots more drag than
> cars,
> and a less efficient propulsion scheme than wheels... (of course, this
> is
> just a "probe" sort of thing, so it might do better. But I dunno if
> they
> can even DO gasoline motors for that sort of craft...)
>
> BillW
>
On Fri, 19 Nov 2004 16:37:26 -0000, Mcgee, Mark <spam_OUTmark.mcgeeTakeThisOuTcsfb.com> wrote:
> Boats usually measure fuel consumption in litres per hour or gallons per hour,
> but I'd imagine, in a straight line over the ground, a boat engine would
> consume more fuel than the car would to make the same journey.
Last weekend I helped my dad bring his boat home from his cabin to
Vancouver. I don't remember the exact numbers, but we burned through
150L (39.6 gallons) of diesel in a 6 hour trip. We averaged about 8.5
knots, or 9.8 mph.
So if I did my math correctly (it's still early in the morning here)
that works out to 6*9.8/39.6 = 1.5 MPG.
Of course, this is in a US military surplus LCVP with a DD 6-71 engine
so it's not the most fuel efficient ship. :)
____________________________________________
At 01:02 PM 17/11/2004 -0000, you wrote:
>
>Hi Guys
>Though that this would be interesting...
>
>http://spray.ucsd.edu/
>
>
>If anybody has any more info please let me know, I think this is just
>brilliant.
>Regards
> Luis
>
>_____________________________________________
The two biggest problems with travel in, or on top of, water are 1) the
resistance the water creates and 2) a 3 blade propeller is only about 50%
efficient. Compared to a car a boat is very inefficient.
I recently did some calculations on power required to move my 28,000 lb
sailboat - it would only take 12hp to make 6.5 knots, but 52hp to make 8.0
knots - it all has to do with the speed/length ratio - the slower you go,
the less hp it takes. I typically burn just over a gallon/hour when making
6.0-6.5 knots. 1 knot = 1.15 statue mile, so 6 knots would be 6.9 mile, so
I get about 6 miles/gallon. The good thing is that since it diesel no used
on a road, I do not have to pay road tax on the fuel!
> Boats usually measure fuel consumption in litres per hour or gallons per hour,
> but I'd imagine, in a straight line over the ground, a boat engine would
> consume more fuel than the car would to make the same journey.
Afaik, boats/ships consume the least amount of fuel per ton transported.
Probably not 2-stroke outboards, but ships definitely do that when
operated under good conditions.
Peter
____________________________________________
>On Fri, 19 Nov 2004, Mcgee, Mark wrote:
>
>>Boats usually measure fuel consumption in litres per hour or gallons per
>>hour,
>>but I'd imagine, in a straight line over the ground, a boat engine would
>>consume more fuel than the car would to make the same journey.
>
>Afaik, boats/ships consume the least amount of fuel per ton transported.
>Probably not 2-stroke outboards, but ships definitely do that when
>operated under good conditions.
> I was in a museum a few weeks ago and saw a WWII torpedo that had a
> small 100-200 CC 4 cylinder radial 4 stroke gas motor complete with a
> compressed air tank for running under water. (Its in Halifax NS if
> anyone is interested) It is a credit to the guy who created it.
There is a lot of info on the web on (old?) torpedo technology, including
steam powered, peroxide, and others. Look for 'wet boiler' on google.
Afaik those small engines were forced very hard, running with 4+at intake
manifold pressure from compressed air (or even compressed oxygen) with
alcohool or other low detonation fuel. They could give 100HP (?) for a few
minutes, and only had to run once. I don't know what model you saw, it
could have been for normal gas. They used 4 stroke instead of 2 stroke
because there was no starter. They opened the air + fuel valves and
air+fuel pressure started the engine by simply expanding through it. The
less expensive 2 stroke cannot be used like this. I have been reading up
on this recently.
Peter
____________________________________________
> On Fri, 19 Nov 2004 16:37:26 -0000, Mcgee, Mark <mark.mcgeeKILLspamcsfb.com> wrote:
>> Boats usually measure fuel consumption in litres per hour or gallons per hour,
>> but I'd imagine, in a straight line over the ground, a boat engine would
>> consume more fuel than the car would to make the same journey.
>
> Last weekend I helped my dad bring his boat home from his cabin to
> Vancouver. I don't remember the exact numbers, but we burned through
> 150L (39.6 gallons) of diesel in a 6 hour trip. We averaged about 8.5
> knots, or 9.8 mph.
>
> So if I did my math correctly (it's still early in the morning here)
> that works out to 6*9.8/39.6 = 1.5 MPG.
1.5MPG for what displacement ? (multiply 1.5MPG by vehicle weight makes
the comparison more fair). F.ex. a well tuned compact car will do 600km in
8 hours on about 80 liters of gas. That car weighs just about 1 ton. So
you can say it can carry 4+100kg at those parameters (say 400kg payload).
So it's 400kg*600km for 80liters or 3000kg*km/liter. And that is a compact
car that is considered economical.
> Of course, this is in a US military surplus LCVP with a DD 6-71 engine
> so it's not the most fuel efficient ship. :)
Maybe but you must take the weight into account. In your case, how much
stuff could you have transported for the same amount of fuel ? I am just
looking up lcvp (wow, this lcvp ? http://www.sproe.com/l/lcvp.html). Ok,
it's max 9tons displacement, carries 1jeep+12men+3crew+assorted hardware.
I'd say 2000kg load. 2000kg*90km/150liters = 1200kg*km/liter. Loses vs.
car, but a SUV would probably be as bad if used instead of the car, and
the boat might beat the car if it would use the same hi-tech wizardry the
cars use now (efi, turbo, computer etc).
Otoh bigger ships have a much larger cargo/empty weight ratio and the
figure becomes better and better. Boats are the most efficient (fuel wise)
means of transport available.
Peter
____________________________________________
On Sat, 20 Nov 2004 12:44:19 -0500 (EST), Peter L. Peres
<.....plpKILLspam.....actcom.co.il> wrote:
> > Of course, this is in a US military surplus LCVP with a DD 6-71 engine
> > so it's not the most fuel efficient ship. :)
>
> Maybe but you must take the weight into account. In your case, how much
> stuff could you have transported for the same amount of fuel ? I am just
> looking up lcvp (wow, this lcvp ? http://www.sproe.com/l/lcvp.html). Ok,
> it's max 9tons displacement, carries 1jeep+12men+3crew+assorted hardware.
> I'd say 2000kg load. 2000kg*90km/150liters = 1200kg*km/liter. Loses vs.
> car, but a SUV would probably be as bad if used instead of the car, and
> the boat might beat the car if it would use the same hi-tech wizardry the
> cars use now (efi, turbo, computer etc).
That's the boat! :) But my dad's is a 68, and we've added a cabin on
top rather than the crew sitting in the engine compartment.
The Detroit Diesel 6-71 (6 cylinders, with 71 ci each) is
supercharged, in fact that's where the hot rodders got the blowers
from to put on their small block V8's... you know the ones with the
big chrome supercharger sticking out of the hood.
It's a 2-stroke diesel though, so I stick by my statement of it not
being the most fuel efficient. :)
>The Detroit Diesel 6-71 (6 cylinders, with 71 ci each) is
>supercharged, in fact that's where the hot rodders got the blowers
>from to put on their small block V8's... you know the ones with the
>big chrome supercharger sticking out of the hood.
>
>It's a 2-stroke diesel though, so I stick by my statement of it not
>being the most fuel efficient. :)
>
>http://www.yachtsurvey.com/comparing_diesel_types.htm
>
>You are definitely right about the improvements that EFI would bring,
>but if it ain't broke, don't fix it. :)
>
>Alex
On Sat, 20 Nov 2004 13:41:19 -0700, ColinC <EraseMEpiclistspam_OUTTakeThisOuTcliponcircuits.com> wrote:
> This seems to be a great engine. Do you know where to get any more info
> on it?
> Thanks,
> Colin
____________________________________________
Thanks mate. I've been looking for info on the 6-71 for a while. DD
doesn't seem to have anything, but you'd think thered be a fan club or
something.
Colin
>I don't, but any old salt would probably know about the 6-71 (or any inline-71).
>
>You can get manuals here:
>
><http://www.marineengine.com/manuals/detroitdiesel/>
>
>
>On Sat, 20 Nov 2004 13:41:19 -0700, ColinC <piclistspam_OUTcliponcircuits.com> wrote:
>
>
>>This seems to be a great engine. Do you know where to get any more info
>>on it?
>>Thanks,
>>Colin
>>
>>
in the "good ole days" a tripple expansion steam engine could move 1 tonne
of cargo
1 mile with the energy released from 1 sheet of victorian writing paper.
>in the "good ole days" a tripple expansion steam engine could move 1 tonne
>of cargo
>1 mile with the energy released from 1 sheet of victorian writing paper.
> in the "good ole days" a tripple expansion steam engine could move 1
> tonne of cargo 1 mile with the energy released from 1 sheet of
> victorian writing paper.
>
Assuming total conversion of mass to energy? That doesn't seem
believable.
Perhaps "a 50 ton cargo ship could transport a additional ton of cargo
with
an ADDED energy equivalent to burning a sheet of writing paper." ?
In any case, it hardly seems like a fair comparison. The vehicle in
question
is NOT a cargo carrier; it's closer to the torpedo mentioned, or a
speedboat.
The "payload" is a small fraction of the total mass, most of which
seems to
be the power supply for the motors/etc.
> in the "good ole days" a tripple expansion steam engine could move 1 tonne
> of cargo
> 1 mile with the energy released from 1 sheet of victorian writing paper.
Let's see what that implies.
Adjust assumptions to suit your version of reality.
Assume that Victorian writing paper is thicker and therefore heavier than
standard writing paper these days - call it 200 gsm (grams per square metre)
against current printer paper of 70 gsm. Assume size was slightly larger
than A4 (quarto?). A4 is about 295mm x 210 mm = 0.06 m^2 or 16 sheets per
m^2 so say Victorian paper is 12 sheets m^2. So one sheet weighs 200/12 =
16.7g or 1/60th of a kg.
If Victorian paper was thinner/lighter etc a lower value will result.
Calorific value of paper as fuel depends on processing - most of the higher
volatiles have gone so I suspect you'd get maybe 3 kWh/kg compared to eg
over 10 kWh/kg for diesel oil or about 6 kWh/kg for alcohol.
3 kWh x 1/60 kg = 0.05 kWh or 50 watt hour or 50 x 3600 = 180,000 watt
seconds = 180,000 Newton-metre seconds or ~= 18,000 kg-m seconds.
Work = Force x distance.
Distance = 1 mile = 1600 metres so force available = 18,000 / 1600 =~ 11 kg.
Reduce this by fuel to drive conversion efficiency.
ie to achieve the above claimed result the 1 tonne of cargo would need to be
able to be moved with a force of not more than 11 kg.
As speed was not specified, nor how level the track etc and/or whether this
was by barge or rail or .... we can take best case assumptions.
If you take a 1 tonne (ton) barge and apply 11 kg force it WILL move in the
water. So your 1 sheet of note paper average would achieve the result, given
no wind. In water you wouldn't get much velocity. (Given the air calculation
below but with Rho = 1000 you get a velocity of about sqrt(1.3/1000) * 45
=~~~~ 1.5 kph. Not really a good formula as other factors appear, but gives
some idea)
Given a level rail track and optimally lubricated sleeve bearings or roller
bearings I can believe that 11kg maintaining force may also suffice. Again,
wind would hurt this. Windage drag is about 0.5 x Rho x Cd x V^2. For a 1
m^2 frontage
110 Newtons = 0.5 x 1.3 x 1 x V^2
~= 13 m/s ~= 45 kph.
ie if air velocity alone was the limiting factor speed is about 45 kph for a
1 tonne load pushed by 11 kg !!!!
Bearing friction and / or water drag are liable to be far greater.
E&OE - check my figures before attempting to win a pub bet with this ;-)
Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
-Douglas Adams
On Mon, 22 Nov 2004 15:03:22 +1300, Russell McMahon
<@spam@apptechKILLspamparadise.net.nz> wrote:
> > in the "good ole days" a tripple expansion steam engine could move 1 tonne
> > of cargo
> > 1 mile with the energy released from 1 sheet of victorian writing paper.
>
> Let's see what that implies.
> Adjust assumptions to suit your version of reality.
>
> Assume that Victorian writing paper is thicker and therefore heavier than
> standard writing paper these days
<snip>
____________________________________________
>>in the "good ole days" a tripple expansion steam engine could move 1 tonne
>>of cargo
>>1 mile with the energy released from 1 sheet of victorian writing paper.
>>
>>
>
>Let's see what that implies.
>Adjust assumptions to suit your version of reality.
>
>Assume that Victorian writing paper is thicker and therefore heavier than
>standard writing paper these days - call it 200 gsm (grams per square metre)
>against current printer paper of 70 gsm. Assume size was slightly larger
>than A4 (quarto?). A4 is about 295mm x 210 mm = 0.06 m^2 or 16 sheets per
>m^2 so say Victorian paper is 12 sheets m^2. So one sheet weighs 200/12 =
>16.7g or 1/60th of a kg.
>
>If Victorian paper was thinner/lighter etc a lower value will result.
>
>Calorific value of paper as fuel depends on processing - most of the higher
>volatiles have gone so I suspect you'd get maybe 3 kWh/kg compared to eg
>over 10 kWh/kg for diesel oil or about 6 kWh/kg for alcohol.
>3 kWh x 1/60 kg = 0.05 kWh or 50 watt hour or 50 x 3600 = 180,000 watt
>seconds = 180,000 Newton-metre seconds or ~= 18,000 kg-m seconds.
>
>Work = Force x distance.
>Distance = 1 mile = 1600 metres so force available = 18,000 / 1600 =~ 11 kg.
>Reduce this by fuel to drive conversion efficiency.
>
>ie to achieve the above claimed result the 1 tonne of cargo would need to be
>able to be moved with a force of not more than 11 kg.
>As speed was not specified, nor how level the track etc and/or whether this
>was by barge or rail or .... we can take best case assumptions.
>
>If you take a 1 tonne (ton) barge and apply 11 kg force it WILL move in the
>water. So your 1 sheet of note paper average would achieve the result, given
>no wind. In water you wouldn't get much velocity. (Given the air calculation
>below but with Rho = 1000 you get a velocity of about sqrt(1.3/1000) * 45
>=~~~~ 1.5 kph. Not really a good formula as other factors appear, but gives
>some idea)
>
>Given a level rail track and optimally lubricated sleeve bearings or roller
>bearings I can believe that 11kg maintaining force may also suffice. Again,
>wind would hurt this. Windage drag is about 0.5 x Rho x Cd x V^2. For a 1
>m^2 frontage
>
> 110 Newtons = 0.5 x 1.3 x 1 x V^2
> ~= 13 m/s ~= 45 kph.
>
>ie if air velocity alone was the limiting factor speed is about 45 kph for a
>1 tonne load pushed by 11 kg !!!!
>Bearing friction and / or water drag are liable to be far greater.
>
>
>E&OE - check my figures before attempting to win a pub bet with this ;-)
>
>
>
> Russell McMahon.
>
>
>
>
>
>
Hate to be anal but I think Russel omitted a small detail.
> > in the "good ole days" a tripple expansion steam engine could move 1
tonne
> > of cargo
> > 1 mile with the energy released from 1 sheet of victorian writing paper.
>
> Let's see what that implies.
> Adjust assumptions to suit your version of reality.
>
> Assume that Victorian writing paper is thicker and therefore heavier than
> standard writing paper these days - call it 200 gsm (grams per square
metre)
> against current printer paper of 70 gsm. Assume size was slightly larger
> than A4 (quarto?). A4 is about 295mm x 210 mm = 0.06 m^2 or 16 sheets per
> m^2 so say Victorian paper is 12 sheets m^2. So one sheet weighs 200/12 =
> 16.7g or 1/60th of a kg.
>
> If Victorian paper was thinner/lighter etc a lower value will result.
Looks good to here!
> Calorific value of paper as fuel depends on processing - most of the
higher
> volatiles have gone so I suspect you'd get maybe 3 kWh/kg compared to eg
> over 10 kWh/kg for diesel oil or about 6 kWh/kg for alcohol.
> 3 kWh x 1/60 kg = 0.05 kWh or 50 watt hour or 50 x 3600 = 180,000 watt
> seconds = 180,000 Newton-metre seconds or ~= 18,000 kg-m seconds.
> Work = Force x distance.
Looks good to here!
> Distance = 1 mile = 1600 metres so force available = 18,000 / 1600 =~ 11
kg.
> Reduce this by fuel to drive conversion efficiency.
Hmm with a Carnot efficiency of ballpark 35% for a steam engine, that gives
a maximum available "force" of only ~4kgf.
> ie to achieve the above claimed result the 1 tonne of cargo would need to
be
> able to be moved with a force of not more than 11 kg.
> As speed was not specified, nor how level the track etc and/or whether
this
> was by barge or rail or .... we can take best case assumptions.
>
> If you take a 1 tonne (ton) barge and apply 11 kg force it WILL move in
the
> water. So your 1 sheet of note paper average would achieve the result,
given
> no wind. In water you wouldn't get much velocity. (Given the air
calculation
> below but with Rho = 1000 you get a velocity of about sqrt(1.3/1000) * 45
> =~~~~ 1.5 kph. Not really a good formula as other factors appear, but
gives
> some idea)
> Given a level rail track and optimally lubricated sleeve bearings or
roller
> bearings I can believe that 11kg maintaining force may also suffice.
Again,
> wind would hurt this. Windage drag is about 0.5 x Rho x Cd x V^2. For a 1
> m^2 frontage
>
> 110 Newtons = 0.5 x 1.3 x 1 x V^2
> ~= 13 m/s ~= 45 kph.
Taking into account "ideal" efficiency, this is more like 28kph.
> ie if air velocity alone was the limiting factor speed is about 45 kph for
a
> 1 tonne load pushed by 11 kg !!!!
> Bearing friction and / or water drag are liable to be far greater.
>
>
> E&OE - check my figures before attempting to win a pub bet with this ;-)
>
Figures checked, and in all, a most impressive post! Did you do this off the
top of your head? Also, since we're assuming "ideal", lets make the load
dense and spherical, with a Cd=0.4. Steel has a density of ~8000 kg/m^3 so
a sphere would be frontal area of about 0.3m^2, pushing the Vmax up to a
very respectable 90kph, even with the 35% Carnot efficiency.
I have always been fascinated by the proposed "spaceships" that work similar
to this, with a very small continuously applied force. Such craft could, in
theory, reach relativistic speeds after just a few generations of service.
Where to store several generations of fuel for even a wimpy thruster seems
to be the big problem!
> Hate to be anal but I think Russel omitted a small detail.
Nah - just used a different assumption set :-).
> Figures checked, and in all, a most impressive post! Did you do this off
> the
> top of your head?
Yes - but no guarantees on how well it relates to reality.
> Also, since we're assuming "ideal", lets make the load
> dense and spherical, with a Cd=0.4. Steel has a density of ~8000 kg/m^3
> so
> a sphere would be frontal area of about 0.3m^2, pushing the Vmax up to a
> very respectable 90kph, even with the 35% Carnot efficiency.
That is on eg ice or with a hover-craft type lift with the hover power not
being part of the calculation.
> I have always been fascinated by the proposed "spaceships" that work
> similar
> to this, with a very small continuously applied force. Such craft could,
> in
> theory, reach relativistic speeds after just a few generations of service.
1 year at 1g ~= C.
An antimatter drive with the propulsion mass being the very major part of
the initial mass would get you well on the way. At least to speeds where
relativistic effects were very significant.
> I would appreciate a pointer to information regarding air starting small
> engines. It could be useful for four stroke model airplanes.
I don't have a link handy but here is a simple trick:
Take an older 4-stroke model engine and find a way to adapt normal shop
air to the intake manifold, perhaps using a piece of hose and a hose
clamp. Plug fuel and bypass air vent temporarily (wax or hot stuff works
great and can be removed later). Set the shop air regulator to 2-3 bar
pressure (not more), fit a propeller and see that the engine runs freely
by hand, and open the air valve, flick it over, and increase pressure
until it runs.
I used to use this method to clean and run in engines after refitting
(with homemade parts). Running the air through an oil pot (bubbler)
provides extra lubrication.
There is at least one small free-flight plastic model airplane (toy) that
uses an air motor and is charged using something like a foot pump. I think
it's by Tomy toys but I am not sure.
In theory adapting a cylindrical switchover valve to the intake manifold
is possible but I don't know what it would do to the weight. What I do
know is that a single cylinder engine will only start with air if the air
is supplied when the crankshaft is first brought to a specific position
(intake valves just opening). A 6+ cylinder engine should start from any
crankshaft angle. On large engines air starting used to be the preferred
way to start (e.g. ww2 submarines - weren't those 2-stroke ? - and
contemporary diesel train engines f.ex.). From what I know the outlet
valves are constrained to open at BDC to help with starting.
I think that multi-cylinder 2-stroke engines can also be started with air
but there is a good chance to blow the crankcase apart with the starting
air. Also starting air pressure must be balanced or kept out of the fuel
system or the fuel system will un-prime itself on start. With injected
engines this is not a problem but most model engines are carburettor
equipped afaik.
Peter
____________________________________________
On Sun, 21 Nov 2004, William Chops Westfield wrote:
> In any case, it hardly seems like a fair comparison. The vehicle in question
> is NOT a cargo carrier; it's closer to the torpedo mentioned, or a speedboat.
> The "payload" is a small fraction of the total mass, most of which seems to
> be the power supply for the motors/etc.
Mass ratio for the boat was something like 6000 out of 9000 lbs (60% ? -
this seems wrong but it's a small boat built for utility - too bad the
waterline is 2 inches below the gunwhale when loaded). No car can compete
with that. A typical SUV carrying 4 people and some luggage will have
600kg load for a total mass of well over 2 tons. Maybe a military or light
utility vehicle can reach the mass ratio of a cargo ship.
As I understand it, engines started by compressed air have either a
conventional starter motor which utilises air instead of electricity as the
motive force (truck motors such as the 71 series utilise this method) or
they use rotary air distributors to inject air into (some of or all of) the
cylinders for what would normally be the power stroke (if the motor was
running) or, as in the case of large marine engines, different cams on the
camshaft within the engines are utilised to time the air injection to the
appropriate part of the piston cycle. There may be other ways around the
timing problems but I can't think of any other way to get past the
compression / power stroke of a conventional 2 or 4 stroke engine.
> As I understand it, engines started by compressed air have either a
> conventional starter motor which utilises air instead of electricity as the
> motive force (truck motors such as the 71 series utilise this method) or
> they use rotary air distributors to inject air into (some of or all of) the
> cylinders for what would normally be the power stroke (if the motor was
> running) or, as in the case of large marine engines, different cams on the
> camshaft within the engines are utilised to time the air injection to the
> appropriate part of the piston cycle. There may be other ways around the
> timing problems but I can't think of any other way to get past the
> compression / power stroke of a conventional 2 or 4 stroke engine.
I don't know about the 71 but I know that on small engines the timing
problem is solved by advancing the exhaust timing a lot mechanically
during starting (exhaust opens during compression cycle and stays open
through exhaust cycle - some small hand-started diesel engines use the
same method to make cranking possible). If the crankshaft is given just a
little momentum to be able to overcome the compression cycle then it will
start on intake manifold pressure alone. The momentum is necessary to
supply the reserve necessary to overcome the compression cycle, which does
no work (it consumes momentum that is returned in the power cycle if the
momentum reserve is sufficient). All the work is done in the aspiration
cycle. I do not know how exactly it works out but it does work after a
fashion (the aspiration valve angle is larger than exhaust angle usually
?). Imho if the initial air impulse is large enough and delivered at the
right time it will supply this momentum.
Also there are cartridge starters for airplane engines. I do not know how
those work (extra valving ?).
>-----Original Message-----
>From: KILLspampiclist-bouncesKILLspammit.edu [RemoveMEpiclist-bouncesTakeThisOuTmit.edu]
>On Behalf Of Peter L. Peres
>Sent: 23 November 2004 08:36
>To: Microcontroller discussion list - Public.
>Subject: Re: [OT]: underwater glider
>
>Also there are cartridge starters for airplane engines. I do
>not know how
>those work (extra valving ?).
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____________________________________________
I'm impressed. That appears to be the one I saw a few weeks ago. 800+ psi manifold pressure does make a difference in power.
w..
"Peter L. Peres" wrote:
> I found a link that probably describes the engine seen by the op:
>
> http://www.weymouthdiving.co.uk/torphist.htm, section 'engines'. 450+hp
> from a small engine ?
>
> Peter
>
> ______________________________________________
csfb.com> wrote:
