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"Austin Shackles" <[email protected]> wrote in message
news:[email protected]...
> On or around Mon, 27 Jun 2005 18:51:47 +0100, Colonel Tupperware
> <[email protected]> enlightened us thusly:
>
>>On Mon, 27 Jun 2005 14:49:22 +0100, Austin Shackles
>><[email protected]> wrote:
>>
>>
>>>
>>>Finally, as to the "fit a more appropriate engine", where's the fun in
>>>that?
>>>But seriously, there's a lot to be said for a double-TDi compared wit
>>>some
>>>other type of 5-litre diesel - parts are easily available and cheap, for
>>>example.
>>>
>>>

>>This man knows about joining engines together.
>>
>>http://uk.zn1300.com/
>>http://www.saltmine.org.uk/kgb/mechshow.html

>
> feckin' amazing.


At one time recently, he's also built 6 cylinder KH engines, based on the
KH250 engines to produce a KH500-I6!! He also produced an absolute monster
of banked engines, more cylinders than you could count (20-something I
believe!). it moved under it's own power, I recall, but it wasn't a revvy
thing due to exhaust and inlet designs. In fact, I heard it said that if
it'd run for more than 10minutes it'd have seized through lack of cooling!!!
Badger.


 
In message <[email protected]>
Austin Shackles <[email protected]> wrote:

> On or around Mon, 27 Jun 2005 12:52:49 +0000 (UTC), beamendsltd
> <[email protected]> enlightened us thusly:
>
> >It's been done for years on railways too, with great success, BUT,
> >two locomotives (of the same class) working in tandem (2 drivers,
> >one in each) only gives a 133% power increase, and in multiple
> >(one driver, using remote controls to the second engine) only gives
> >a 150% increase - an exact anology to our two 4-cylinder engines
> >bolted together.

>
> not quite. There's no solid link between the 2 engines - in the railway
> engine case, depending on transmissions, it would be possible for one engine
> to be pulling faster than the other one was running. However, if they're
> both running at a power output and transmission setting suitable to run at
> e.g. 60 mph, then they should both contribute more-or-less equally.
>


They would - but getting them to match is not possible, hence losses
get introduced into the overall system.

> Going back to the 2 engines, again. Suppose I run one engine at idel and
> the pother at full chat, obviously, the one at idle is doing nothing and is
> in fact absorbing power. But suppose one is running at 3000 rpm and the
> other, on the same setting, would in normal circumstances be running at
> 2900, the one running at 3000 will still be doing more of the work, but the
> second one will be contributing something significant, albeit not full
> power. Now suppose that I set the thing up on a dyno, open the throttle to
> an appropriate setting (say 2500 rpm for a TDi) I can then tweak one of the
> pumps/linkages 'til I get maximum output. If they run through 2 separate
> exhausts (which would make sense) I can also assess the smoke from each
> separately.


The one running at 2900rpm will cause the one running at 3000rpm
to think it needs to increase fueling to maintain its speed, hence
the slower engine will viewed as a brake on the faster one and the
system, now in imbalance, will be inefficient.
>
> I don't doubt that it's impossible, practically and maybe theoretically, to
> get twice the output, but by careful setting up I reckon you should get
> enough to make it worth while.
>


Obviously I don't!

Richard

--
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In message <1119881986.86567d2901a61f18113cfa24bd5ba594@teranews>
"Nigel Hewitt" <[email protected]> wrote:

> beamendsltd wrote:
>
> > The major problem would be to get the two engines running the
> > characteristic, i.e. not fighting each other. I guess (from
> > railway locomitives) that you'd be lucky to get 150% more
> > power than a single engine. Somewhere on the web is a discourse
> > by someone who put 2 (proper) Mini engines together, complete
> > with the maths on why the power output isn't simply x2

>
> Any details on this because as a simple minded physicist
> I'm pushed to see how an engine at a set revs with the
> pedal down does not deliver its rated torque regardless
> what the load looks like.
>


The point is that no two engins *are* the same - the rated figures
just a statement of roughly what can be expected, not a statement
for that particular engine.

> I just can't see power vanishing. Conservation of energy
> is a pretty basic law of the universe.


If one engine is not excactly the same as the other, one will
try to drive the other, an the other will back off as it
tries to maintain it's speed, putting a further load on the
first one - there's you loss. Try turing an engine
over by hand and see how much energy is required.

>
> nigelH
>
>


Richard

--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
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Helping keep Land Rovers on and off the road to annoy the Lib Dems
 
In message <[email protected]>
"Badger" <[email protected]> wrote:

>
> "Nigel Hewitt" <[email protected]> wrote in message
> news:1119881986.86567d2901a61f18113cfa24bd5ba594@teranews...
> > beamendsltd wrote:
> >
> >> The major problem would be to get the two engines running the
> >> characteristic, i.e. not fighting each other. I guess (from
> >> railway locomitives) that you'd be lucky to get 150% more
> >> power than a single engine. Somewhere on the web is a discourse
> >> by someone who put 2 (proper) Mini engines together, complete
> >> with the maths on why the power output isn't simply x2

>
> I suggest he buys a new calculator, then. Acceleration time won't half by
> doubling the power, because you've added weight. It can be easily worked out
> by the following equation, though.
> Force (F) = Mass (Kg) x Acceleration (m/s2)


Nice in theory, but in reality all the losses in the system have
accounted for. On paper, putting a winch cable through a snatch
block and back to the winch doubles the pulling power of the
winch. Are you suggesting that 100% efficiency is attainable?

>
> > Any details on this because as a simple minded physicist
> > I'm pushed to see how an engine at a set revs with the
> > pedal down does not deliver its rated torque regardless
> > what the load looks like.
> >
> > I just can't see power vanishing. Conservation of energy
> > is a pretty basic law of the universe.

>
> Indeed. Well said that man.


If ignoring losses.

> Badger.
>
>


Richard

--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Helping keep Land Rovers on and off the road to annoy the Lib Dems
 
In message <[email protected]>
"Badger" <[email protected]> wrote:

>
> "beamendsltd" <[email protected]> wrote in message
> news:78459a814d%[email protected]...
> <<big snip!>>
> >> I think you might just be missing the point here, the different cylinders
> >> within a single engine can in practice operate at differing efficiency
> >> levels to their adjacent cylinders, due mainly to inlet and exhaust
> >> breathing capabilities. This is very obvious on a carb rover V8, where
> >> the
> >> outer 4 cylinders (1,2,7&8) do not get the same inlet charge volume as
> >> the
> >> other 4, mainly down to the design of the inlet manifold. If you were to
> >> bolt two theoretically identical 4-cyl engines together, then at worst
> >> you'd
> >> be no worse off charge efficiency wise than a std V8.

> >
> > I don't beleive I am missing the point at all - the V8 is a closed system,
> > i.e. inouts to one or more cylinders have a direct efffect on the
> > total output of the system. Bolting 2 4-cylinder eninges together
> > is trying to run two independent closed systems together, not
> > the same thing at all.

>
> Ok then, take an I4 engine with a single SU carb, bolt another identical I4
> engine to it to make it a twin carb I8. Now, apart from the fact that the
> resultant engine is 2 blocks bolted together and a joining sleeve/spline on
> the now 2-piece crank(s), why is that suddenly so different from an I8
> engine with a single block casting and 2 carbs and a dual-point dizzy, where
> each set of points feeds 4 cylinders (preventing points bounce at higher
> rpm's)?? Answer, it isn't!


It is - 2 independent systems bolted together is not the same as one
designed to be so - the latter set up you describe is *designed* to be
that way, not cobbled together.

>
> >> It's been done for
> >> years in tractor-pulling circles, using nose-to-tail, chain, belt, and
> >> collector gearbox types of systems, all with reasonable success. They
> >> even
> >> join the outputs from Isotov gas turbine engines, one machine having 3 of
> >> the damn things feeding into a collector gearbox!

> >
> > And how long do they last?

>
> "Corskie Supertramp", over 12 years that I know of and still pulling strong
> with a multiple (6) rover V8 setup. I once remember it throwing a rod out
> the side of a block, but that was due to it being run at too high an rpm,
> nothing else.
> One (forget its name, might be Midnight Express?) with 4 (or6) jag XK 4.2's
> and a V12 on top!! (Drive belt issues, but engines all ok after a good few
> years)
> Now, that's just 2 for starters that are based in the North of Scotland that
> I know of, there are many, many more up and down the country and on the
> continent, and if banking engines up together, either in series through a
> common crank output or in parallel via chains, belts etc didn't work or was
> seriously problematic, they wouldn't do it!
>
> > It's been done for years on railways too, with great success, BUT,
> > two locomotives (of the same class) working in tandem (2 drivers,
> > one in each) only gives a 133% power increase, and in multiple
> > (one driver, using remote controls to the second engine) only gives
> > a 150% increase - an exact anology to our two 4-cylinder engines
> > bolted together.

>
> Sorry, I can't see the logic in that at all. If I have 2 loco's each having
> an individual, separate, tractive effort of say 10, then I have a total
> combined tractive effort of 20. There is no extra work lost to friction etc
> by either engine as it is still pulling its own weight along, so neither
> robs any tractive effort from the other! If I have 2 engines, each of
> 200bhp, then I have 400bhp in total if they are utilised correctly. Either
> engine's power output doesn't simply drop off just because it is now working
> alongside another! The laws of physics couldn't be true otherwise.
> It's fair to say, however, that adding 2 2litre 200bhp engines together to
> make a new single engine of 4 litres will not automatically give 400bhp,
> this is due to pumping losses and friction.
>
> << another big snip >>


ok - I give up! Obvioulsy the entire railway (and for that matter, marine)
industry has got it wrong for all these years!

>
> >> Multi-carbs were traditionally used so that individual port runner gas
> >> velocity could be maintained as high as possible in the interests of
> >> mid-range torque, in addition to the engineering problems encountered
> >> when
> >> trying to make one carb feed a largeish engine from idle to max. The port
> >> runner issue still stands today, look at the length of the runners
> >> including
> >> the trumpets feeding a v8, and consider why the outer 4 are a different
> >> length to the others, in respect to my first para of this post.

> >
> > To make the compromise work.

>
> No, it was done as a deliberate compromise to the engine's power delivery
> characteristics, not as a compromise to make something work in the first
> place! If both carbs were opened simultaneously, the sudden torque rush was
> too severe when coupled with either 1. an auto when pulling away from rest
> or 2. when trundling along in heavy traffic and feathering the throttle at
> very low rpm without using (slipping) the clutch.
> In both cases the designers introduced an efficiency (cylinder power
> balance) compromise in the interests of user-friendliness and driveability,
> Proving that at lower power and rpm settings you really don't need to have
> all cylinders perfectly matched. The important things are 1. that all idle
> stops/mixture screws are in balance and 2. all reach full throttle at the
> same time.
> Badger.
>


I could go into the details of why the above paragraph is wrong, excpet
for repeating again that it's the result of the compromise to make
the system work at all, not a design goal.
I could also bang on about the engine management ECU I worked on
(Fitted to larger Volvo, almost all DAF, Dawoo, Hyundai and other
Far Eastern truck and bus engines) which can so nearly balance each
cylinder (configurable from 4 to 16 cylinders, any format) perfectly
that any one cyinder can be identified as being weaker than the others
(indicating some potential future failure, and whether is fuel or
mechanical) and injectors can be switched off in a rotating cycle to
imporve fuel efficiency when cruising without intriducing whip in the
crank.
Engine mangement has moved on a hell of a lot from the Rover V8 (hence
it's demise) and carbs are well and truly consigned to history.

>


Richard
--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Helping keep Land Rovers on and off the road to annoy the Lib Dems
 

>
>Nice in theory, but in reality all the losses in the system have
>accounted for. On paper, putting a winch cable through a snatch
>block and back to the winch doubles the pulling power of the
>winch. Are you suggesting that 100% efficiency is attainable?
>


<pedantic>
Power is force multiplied by velocity. The snatch block doubles the
force whilst halving the speed. Hence power remains the same.
</pedantic>


--

Tim Hobbs

'58 Series 2 88" aka "Stig"
'77 101FC Ambulance aka "Burrt"
'03 Volvo V70
 
beamendsltd wrote:

> If one engine is not excactly the same as the other, one will
> try to drive the other, an the other will back off as it
> tries to maintain it's speed, putting a further load on the
> first one - there's you loss.


I don't actually see this - an engine doesn't see speed as a control
variable does it, only load.

ELECTRICAL machines can often be mechanically connected as well as
electrically, and give the expected o/p.

Not that I disagree with the general physical principle of Tanstaafl
(look it up), but because I like a good fight.

Steve
 
Tim Hobbs wrote:
>>Nice in theory, but in reality all the losses in the system have
>>accounted for. On paper, putting a winch cable through a snatch
>>block and back to the winch doubles the pulling power of the
>>winch. Are you suggesting that 100% efficiency is attainable?
>>

>
>
> <pedantic>
> Power is force multiplied by velocity. The snatch block doubles the
> force whilst halving the speed. Hence power remains the same.
> </pedantic>


....of course Effy is My Aunt who is Very Rude. So efficiency falls.

Steve
 
On or around Tue, 28 Jun 2005 10:30:17 +0000 (UTC), beamendsltd
<[email protected]> enlightened us thusly:

>
>ok - I give up! Obvioulsy the entire railway (and for that matter, marine)
>industry has got it wrong for all these years!


butbut, hangon. The railways sometimes use 4 or 5 power units on the front
of a 3-mile-long train of wagons. If there's this law of diminishing
returns as you say and to the extent you say, the 3rd, 4th etc. are not
doing anything at all, which can't be right - they'd only use 2 locos.

In the question of 2 engines, I grant that you're never except by luck going
to get all the power from both engines, but an engine running at 3000 rpm
(say) with a fuel setting somewhere close to what it needs to run at that
speed (but not exactly right) will be burning fuel and turning that fuel
into mechanical energy. Suppose that the "master" engine is generating
70bhp, and the "slave" is running slightly underfuelled due to an imbalance
of controls, and is only generating 60 bhp as a result - that 60 bhp is
still there and still being used to propel the vehicle. Granting that the
individual engines are not made to accurate enough specs that you can
guarantee to synchronise them at more than 1 engine speed, I doubt that
they'll differ by more than 10%, if suitably tuned.

>Engine mangement has moved on a hell of a lot from the Rover V8 (hence
>it's demise) and carbs are well and truly consigned to history.


I suppose you could, with such a system, run the proposed pair of engines -
it'd doubtless not be viable. I assume it's running all cylinders
individually.

Getting back to the point, though. Using a standard mechanical injection
pump and spring-loaded injectors, it's highly likely that your ordinary
4-cylinder engine has imbalances which mean that not all of them contribute
exactly to the running of the engine. However, the overall effect is more
powerful than a 2-cylinder 1250cc engine.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".
 
On or around Tue, 28 Jun 2005 10:30:18 +0000 (UTC), beamendsltd
<[email protected]> enlightened us thusly:

>
>The one running at 2900rpm will cause the one running at 3000rpm
>to think it needs to increase fueling to maintain its speed, hence
>the slower engine will viewed as a brake on the faster one and the
>system, now in imbalance, will be inefficient.


Yeah, but then again, I'd be disappointed with a setup that gave an
imbalance as big as 100 rpm in 3000. I'd expect to be able to get them
closer than that.


too, there are these guys with multi-engine tractor-pulling machines - OK,
that's partly for show. But even so, they must get some gain from it to be
worth the effort, else why don't they simply fit a 14-litre Cummins with 4
turbos.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".
 
On or around Tue, 28 Jun 2005 12:06:10 +0100, Steve Taylor
<[email protected]> enlightened us thusly:

>beamendsltd wrote:
>
>> If one engine is not excactly the same as the other, one will
>> try to drive the other, an the other will back off as it
>> tries to maintain it's speed, putting a further load on the
>> first one - there's you loss.

>
>I don't actually see this - an engine doesn't see speed as a control
>variable does it, only load.


not exactly. more a mixture of the 2. The diesel pump contains a governor
which responds to engine revs. Increased load decreases revs and the
governor supplies more fuel, although it's also related to the position of
the throttle. Driving a diesel (mechanical injection type, natch) with a
fixed throttle however doesn't make it run at an exact RPM - the revs will
drop under load and increase off-load, by a certain amount.

>
>Not that I disagree with the general physical principle of Tanstaafl
>(look it up), but because I like a good fight.


the thing is, you're not trying to get something for nothing - to use the
full power available you have to supply twice as much fuel.
--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".
 
On 2005-06-28, beamendsltd <[email protected]> wrote:

> If one engine is not excactly the same as the other, one will try to
> drive the other, an the other will back off as it tries to maintain
> it's speed, putting a further load on the first one - there's you
> loss. Try turing an engine over by hand and see how much energy is
> required.


Whack a diff in there with the engines where the halfshafts would be
and the power being delivered to the prop rather than being delivered
by it, that would sort it. You'd have to modify the diff and make
sure the engines drove the shafts in the right direction though!

Dax do/did a line in Lotus 7 replicas that have dual motorbike
engines, one driving the front wheels, the other driving the rear.
IIRC they had two motorbike gearboxes with the engine/gearbox
combinations being mechanically unconnected, with speed/power matching
being done by electronics. They're quite quick. IIRC they held the
0-60 dash world record and a few others until the Ultima GTR came
along and monstered it using a basic 800kg car with space-frame
chassis, 13-inch wide tyres and 650BHP carburetted Chevvy. MMMmmmm
nice.

--
For every expert, there is an equal but opposite expert
 
In message <[email protected]>
Austin Shackles <[email protected]> wrote:

> On or around Tue, 28 Jun 2005 10:30:18 +0000 (UTC), beamendsltd
> <[email protected]> enlightened us thusly:
>
> >
> >The one running at 2900rpm will cause the one running at 3000rpm
> >to think it needs to increase fueling to maintain its speed, hence
> >the slower engine will viewed as a brake on the faster one and the
> >system, now in imbalance, will be inefficient.

>
> Yeah, but then again, I'd be disappointed with a setup that gave an
> imbalance as big as 100 rpm in 3000. I'd expect to be able to get them
> closer than that.
>


Well, I can't be doing the calcs, but when I bought my 110 it
would just about do 85mph, now it will do 95 quite easily, so
the characteristics of the engine have changed quite dramatically
over the years - trying to match it with its original self
would show a wild difference.

>
> too, there are these guys with multi-engine tractor-pulling machines - OK,
> that's partly for show. But even so, they must get some gain from it to be
> worth the effort, else why don't they simply fit a 14-litre Cummins with 4
> turbos.
>


It's alot more than partly for show. I'm sure if the rules were "open"
then they would just pop out and get one of those Russian 8x8's or
a massive quarry machine - not very much of a crowd pleaser.

Richard
--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Helping keep Land Rovers on and off the road to annoy the Lib Dems
 
In message <[email protected]>
Austin Shackles <[email protected]> wrote:

> On or around Tue, 28 Jun 2005 10:30:17 +0000 (UTC), beamendsltd
> <[email protected]> enlightened us thusly:
>
> >
> >ok - I give up! Obvioulsy the entire railway (and for that matter, marine)
> >industry has got it wrong for all these years!

>
> butbut, hangon. The railways sometimes use 4 or 5 power units on the front
> of a 3-mile-long train of wagons. If there's this law of diminishing
> returns as you say and to the extent you say, the 3rd, 4th etc. are not
> doing anything at all, which can't be right - they'd only use 2 locos.


Exactly - that's why the South Wales iron ore trains had the three
Class 37 locomotives (1750hp x 3) replaced with a single Class 56 -
4000hp!

>
> In the question of 2 engines, I grant that you're never except by luck going
> to get all the power from both engines, but an engine running at 3000 rpm
> (say) with a fuel setting somewhere close to what it needs to run at that
> speed (but not exactly right) will be burning fuel and turning that fuel
> into mechanical energy. Suppose that the "master" engine is generating
> 70bhp, and the "slave" is running slightly underfuelled due to an imbalance
> of controls, and is only generating 60 bhp as a result - that 60 bhp is
> still there and still being used to propel the vehicle. Granting that the
> individual engines are not made to accurate enough specs that you can
> guarantee to synchronise them at more than 1 engine speed, I doubt that
> they'll differ by more than 10%, if suitably tuned.


I absolutely agree, though the loss is going to be more than 10% IMO,
except that the hp from one is "fighting" against the other to try
to obtan the desired speed/power from the its partner, so rather than
driving the load the engines are trying to drive each other, hence the
loss.

>
> >Engine mangement has moved on a hell of a lot from the Rover V8 (hence
> >it's demise) and carbs are well and truly consigned to history.

>
> I suppose you could, with such a system, run the proposed pair of engines -
> it'd doubtless not be viable. I assume it's running all cylinders
> individually.
>
> Getting back to the point, though. Using a standard mechanical injection
> pump and spring-loaded injectors, it's highly likely that your ordinary
> 4-cylinder engine has imbalances which mean that not all of them contribute
> exactly to the running of the engine. However, the overall effect is more
> powerful than a 2-cylinder 1250cc engine.
>


Obviously, unless the 4-cylinder was incredibly badly designed.

Richard
--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Helping keep Land Rovers on and off the road to annoy the Lib Dems
 
On or around Tue, 28 Jun 2005 16:06:27 +0000 (UTC), beamendsltd
<[email protected]> enlightened us thusly:

>Exactly - that's why the South Wales iron ore trains had the three
>Class 37 locomotives (1750hp x 3) replaced with a single Class 56 -
>4000hp!


yeah, but what about the Australian ores trains and suchlike, with several
locos, which IIRC they still do?

I suspect the class 56 replacing the class 37s might also be about running
one more modern unit, with attendant savings in fuel consumption and
maintenance.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".
 
On or around Tue, 28 Jun 2005 16:06:25 +0000 (UTC), beamendsltd
<[email protected]> enlightened us thusly:

>Well, I can't be doing the calcs, but when I bought my 110 it
>would just about do 85mph, now it will do 95 quite easily, so
>the characteristics of the engine have changed quite dramatically
>over the years - trying to match it with its original self
>would show a wild difference.


well, aye. But you could fettle and tune the engines to similar state. Has
yours done that spontaneously, or have you worked on it to achieve more
power/torque?

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".
 
On or around Tue, 28 Jun 2005 21:24:52 +0100, Austin Shackles
<[email protected]> enlightened us thusly:

>On or around Tue, 28 Jun 2005 16:06:25 +0000 (UTC), beamendsltd
><[email protected]> enlightened us thusly:
>
>>Well, I can't be doing the calcs, but when I bought my 110 it
>>would just about do 85mph, now it will do 95 quite easily, so
>>the characteristics of the engine have changed quite dramatically
>>over the years - trying to match it with its original self
>>would show a wild difference.

>
>well, aye. But you could fettle and tune the engines to similar state. Has
>yours done that spontaneously, or have you worked on it to achieve more
>power/torque?


Further to this I've been experimenting with NAD Ford this morning, which
has a bosch mechanical pump on it.

With the throttle held steady (well, as steady as you can do with a foot
pedal) at moderate revs, in 3rd, the speed varied with gradient anything
between about 20 and 35. Giving it more throttle made it go faster, and
backing off the throttle when on a downhill made it slow down.

The gist of all that is that while the governor in the pump does indeed vary
the fuel supply, it doesn't do so with a very wide range - if the governor
was capable of varying the fuel between max and min fuel levels, I'd expect
it to sit at a single speed much more closely. Clearly, the governor is not
able to shut the fuel supply off, and equally, it doesn't supply maximum
fuel unless the revs drop quite a long way from the base settting, although
past experience with these pumps on another engine leads me to believe that
if you do something silly and get it to almost-stall, it does actually pull
much harder than you might expect.

It might be that the governor is deliberately set up like that to make it
more driveable, I suppose. In railway terms, you'd not need to do that;
since in general they employ non-rigid transmission systems, mostly
diesel-electric these days. With such systems, it'd probably be better to
have a governor that responds fast and hard, so that when you increase the
load, it supplies fuel ASAP to meet the demand. With a mechanical
transmission, I suspect it'd prove difficult to drive it smoothly.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".
 
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