Bukh Starting
Ian Sandell
cold start device but the manual refers to a Thermostart Valve (?) as
a optional extra. The compression seems good (but not measured) and
the head and injectors have recently been overhauled.
Does anyone have experience of Bukhs?
Ian
Guy Fawkes
wrote:
have you got an "excess fuel" button on the pump?
do you crak with throttle wide open?
is your starter motor lazy?
how do you know compression is good?
--
"Time flies like an arrow,
fruit flies like a banana."
Š Guy Fawkes - Binary Year 11111010000
mark
Sympathies.
How old is the Bukh.
Both my boats have had Bukh 10's, of 25 year antiquity. Both with wretched
dynostarts.
But that's all I have been able to afford, but that's another matter.
My first Bukh had no 'easy' starting system. To get it to start in the
winter meant using a squirt of ether. There is a lot of bad press for ether,
but it got the engine started, and as far as I have heard has had not bad
effect on the engine since. (sold 3 years ago)
My 2nd Bukh has a small inferno device in the air intake. There is a diesel
drip which ignites, and catches fire, this provides hot air for the piston.
With this device, it can still take three goes to get the engine to fire in
the winter.
The major MUST, is to have well charged batteries. If they are sluggish,
then you will be very lucky to get the engine going. Are you in a marina
with access to power?
Both mine have been 10's whereas your 20 will need that much extra power to
turn it.
There are a lot of 'old wives tales' methods of warming the air intake.
Flaming rags always seemed a bit tricky to me, I did wonder about using a
blow torch, but found I didn't have a spare hand to hold it, as starting a
Bukh is a two handed job!
No doubt we shall hear many whacky ideas on how to start a diesel.
The Bukh is without a doubt a very good engine, reliable and economical. But
having seen the Yanmar engine on a friends boat, it was just like a car
engine, a turn of the key and it was running. Seemed like a good idea, until
I priced putting a new engine in. In the end, I opted to have a top end
overhaul, which proved the engine was in good condition, and have opted to
pay for electricity on the boat during the winter. Thus I have fully charged
batteries, and a warm boat. :-))
I don't suppose that's of much help, but its how I have overcome the Bukh
starting difficulties.
Regards
Mark Johnson
"Eilidh"
Halcyon 27
Swansea
http://www.markland.demon.co.uk/mja.htm
Ian Sandell wrote in message ...
>I have a Bukh 20 which runs fine but is a bugger to start. It has no
>cold start device but the manual refers to a Thermostart Valve (?) as
>a optional extra. The compression seems good (but not measured) and
>the head and injectors have recently been overhauled.
>
>Does anyone have experience of Bukhs?
>
>Ian
Guy Fawkes
wrote:
>No doubt we shall hear many whacky ideas on how to start a diesel.
one (small) squirt of engine oil will do it
--
"Time flies like an arrow,
fruit flies like a banana."
© Guy Fawkes - Binary Year 11111010000
Geoff Blake
: On Sun, 12 Mar 2000 10:51:34 -0000, "mark" <ma...@markland.demon.co.uk>
: wrote:
: >No doubt we shall hear many whacky ideas on how to start a diesel.
: one (small) squirt of engine oil will do it
Particularly if the engine has low compression caused by work bores. The oil
improves the seal and thus the compression for a short while.
To start a diesel you need two things, "hot air" and fuel. The fuel is
required to be injected (atomised) at the right time. "Hot air" is caused by
sufficient compression, a clear air intake/exhaust system and fast enough
rotation.
From what you say, the fuel side is OK, so you probably miss out on lack of
compression or lack to starter spin speed. My guess is probably the latter.
Ideally, on a small engine you need to spin it at around idling speed, say
600 rpm. Does your starter do that?
Geoff
--
Geoff Blake geoff (at) palaemon . co . uk linux 2.0.36
Chelmsford g8gnz @ g8gnz . ampr . org sparc - i586
Please, only use the .ampr.org address if you know what you are doing
Intel create faster processors - Microsoft create slower processes
Rainer Thonnes
ge...@nospam.demon.co.uk (Geoff Blake) writes:
>
>From what you say, the fuel side is OK, so you probably miss out on lack of
>compression or lack to starter spin speed. My guess is probably the latter.
>Ideally, on a small engine you need to spin it at around idling speed, say
>600 rpm. Does your starter do that?
If not, might it be worth opening the decompression levers so that the
starter can get the engine turning over with less effort, just as one
would do with hand-starting if one were feeling optimistic? Then let
it run like that for a few seconds before switching compression back on.
Ian Sandell
wrote:
Thanks for info. My Bukh is about 17 years old. I don't think it has
had much use, perhaps too little. It has a starter (rether than
Dynastart) but I believe that the 20 had the same starter as the 10.
I was wondering about trying to fit a "Thermostart" valve but I won't
bother after your description. A squirt of easystart seems to work
well.
I am on a pontoon at present but soon move to a pile mooring so won't
have electric power, but I don't think the battery power is a problem.
Ian
>Ian,
>
>Sympathies.
>
>How old is the Bukh.
>
>Both my boats have had Bukh 10's, of 25 year antiquity. Both with wretched
>dynostarts.
>
>But that's all I have been able to afford, but that's another matter.
>
>My first Bukh had no 'easy' starting system. To get it to start in the
>winter meant using a squirt of ether. There is a lot of bad press for ether,
>but it got the engine started, and as far as I have heard has had not bad
>effect on the engine since. (sold 3 years ago)
>
>My 2nd Bukh has a small inferno device in the air intake. There is a diesel
>drip which ignites, and catches fire, this provides hot air for the piston.
>With this device, it can still take three goes to get the engine to fire in
>the winter.
>
>The major MUST, is to have well charged batteries. If they are sluggish,
>then you will be very lucky to get the engine going. Are you in a marina
>with access to power?
>
>Both mine have been 10's whereas your 20 will need that much extra power to
>turn it.
>
>There are a lot of 'old wives tales' methods of warming the air intake.
>Flaming rags always seemed a bit tricky to me, I did wonder about using a
>blow torch, but found I didn't have a spare hand to hold it, as starting a
>Bukh is a two handed job!
>
>No doubt we shall hear many whacky ideas on how to start a diesel.
>
Ian Sandell
<guy.f...@error404.surfbaud.co.uk> wrote:
See in-line.
>>I have a Bukh 20 which runs fine but is a bugger to start. It has no
>>cold start device but the manual refers to a Thermostart Valve (?) as
>>a optional extra. The compression seems good (but not measured) and
>>the head and injectors have recently been overhauled.
>>
>>Does anyone have experience of Bukhs?
>have you got an "excess fuel" button on the pump?
As I said, it has no cold starting device
>do you crak with throttle wide open?
Yes
>is your starter motor lazy?
Don't know. What should cranking revs be?
>how do you know compression is good?
As I said, seems good (ie turning engine over is hard than 2 litre
petrol engine) but compression has not been measured.
Ian
Ian Sandell
Blake) wrote:
>From what you say, the fuel side is OK, so you probably miss out on lack of
>compression or lack to starter spin speed. My guess is probably the latter.
>Ideally, on a small engine you need to spin it at around idling speed, say
>600 rpm. Does your starter do that?
>
>Geoff
Thanks, I'll check at the weekend. BTW, why do you think it's starter
speed?
Ian
Guy Fawkes
wrote:
>>have you got an "excess fuel" button on the pump?
>
>As I said, it has no cold starting device
just checking
>>is your starter motor lazy?
>
>Don't know. What should cranking revs be?
check with bukh, in excess of 200, prolly about 225 oi reckon
>
>>how do you know compression is good?
>
>As I said, seems good (ie turning engine over is hard than 2 litre
>petrol engine) but compression has not been measured.
measure it, doesn't cost much, watch closely, it shouldn't build much
before starting....
--
"Time flies like an arrow,
fruit flies like a banana."
Š Guy Fawkes - Binary Year 11111010000
Phil T
June July than it does in February?
The air is cold and damp and that is what enters the air intake along with
any
condensation already inside.
It doesn't start well and because of this you try a few times the battery
gets lower the motor turns slower yep you need a miracle, am I right so far?
Solution......sail it to Canary Islands always warm, always fair winds don't
need an engine and plenty of "neked wimen" and cheap beer to cheer you up!
--
Phil.
(Remove NOSPAM to reply by e-mail)
This message is classified "VERY TOP SECRET"
Ian Sandell <I...@sandell.co.uk> wrote in message
news:p9oqcs0av8dvfmehl...@4ax.com...
Guy Fawkes
<phi...@turgoose.freeserve.co.uk> wrote:
>My guess would be it is cold. What I mean is I bet it starts a lot better in
>June July than it does in February?
>The air is cold and damp and that is what enters the air intake along with
>any
>condensation already inside.
well, low temperature means thicker oil, which takes more power to
crank, and low temperature means metal components contract to piston /
ring / sleeve gap increases and seal decreases (unless you are a well
know lecturer in egineering in which case the two will cancel out and
temperature will make no difference) thus making starting harder, but
on the other hand cold air is dense (hence intercoolers) so
compression is up and starting is easier, a touch of damp in the air
is good too, motors always run better on a wet day (electrical systems
apart)
>It doesn't start well and because of this you try a few times the battery
>gets lower the motor turns slower yep you need a miracle, am I right so far?
>
>Solution......sail it to Canary Islands always warm, always fair winds don't
>need an engine and plenty of "neked wimen" and cheap beer to cheer you up!
_now_ you're making sense, the sight of half a dozen nekkid women
rowing to tow your boat around will make a lazy bukh seem like a
godsend....
PyroJames
Guy Fawkes <guy.f...@error404.surfbaud.co.uk> wrote in message
news:fj4scs0kv59dbfj19...@4ax.com...
> On Tue, 14 Mar 2000 00:32:44 -0000, "Phil T"
> <phi...@turgoose.freeserve.co.uk> wrote:
>
> >My guess would be it is cold. What I mean is I bet it starts a lot better
in
> >June July than it does in February?
> >The air is cold and damp and that is what enters the air intake along
with
> >any
> >condensation already inside.
>
> well, low temperature means thicker oil, which takes more power to
> crank, and low temperature means metal components contract to piston /
> ring / sleeve gap increases and seal decreases (unless you are a well
> know lecturer in egineering in which case the two will cancel out and
> temperature will make no difference) thus making starting harder, but
> on the other hand cold air is dense (hence intercoolers) so
> compression is up and starting is easier, a touch of damp in the air
> is good too, motors always run better on a wet day (electrical systems
> apart)
>
Would you like to explain how the change in air density increases the
compression ratio in an engine? And, assuming that both the sleeve and the
piston are iron/steel, that the gap between them will change given a
temperature change?
Perhapes you would like to consider how an compression ignition engine
works, and how diesel is ignited? And perhapes why motors run better on a
wet day, but are not actually easier to start under those circumstances?
Perhapes it might have something to do with vapourisation?
--
James Kelman
"Dawn Wind of Kirribilli"
Titchmarsh, Essex, UK.
Chris Harris
> Would you like to explain how the change in air density increases the
> compression ratio in an engine? And, assuming that both the sleeve and the
> piston are iron/steel, that the gap between them will change given a
> temperature change?
The piston will not be iron/steel though will it? It will be made from the
lightest strongest material available, some form of aluminium in a
commercial engine.
Cheers
Geoff Blake
: On Sun, 12 Mar 2000 17:57:37 GMT, ge...@nospam.demon.co.uk (Geoff
: Blake) wrote:
: >From what you say, the fuel side is OK, so you probably miss out on lack of
: >compression or lack to starter spin speed. My guess is probably the latter.
: >Ideally, on a small engine you need to spin it at around idling speed, say
: >600 rpm. Does your starter do that?
: >
: >Geoff
: Thanks, I'll check at the weekend. BTW, why do you think it's starter
: speed?
A diesel fires because the fuel is injected into hot air (can't remember how
hot but about 400 deg C.). The air is heated by compression (bycycle pump
and heat is lost through the cylinder walls. The faster the rotation, the
less heat is lost before injection.
Spring (powered) starters concentrate all their energy in spinning the
engine over one revolution and expecting it to fire and thus keep the engine
spinning....
Guy Fawkes
<J.Ke...@SPAMcranfield.ac.uk> wrote:
>
>Guy,
oh dear, here we go with the "i don't like fawkes cos he's rude so
everything he says must be shit".....
>Would you like to explain how the change in air density increases the
>compression ratio in an engine?
how can it fail to, a greater mass of denser cold air will fit into
any given volume, say a cylinder bore at BDC, than the same volume of
hot air,,,,,,,
> And, assuming that both the sleeve and the
>piston are iron/steel, that the gap between them will change given a
>temperature change?
when _was_ the last time you saw an iron piston..... _DO_ learn to
think before trolling
>
>Perhapes you would like to consider how an compression ignition engine
>works, and how diesel is ignited?
I do not have to consider it, I am on intimate terms with it. it's all
heat of compression and flash point.
> And perhapes why motors run better on a
>wet day, but are not actually easier to start under those circumstances?
they _are_ easier to start, unless they have a poorly maintained
electrical system.....
>
>Perhapes it might have something to do with vapourisation?
fuck all to do with it, it _is_ all to do with free electrons, which
is how the flame path spreads........
I await with baited breath your next "discovery", that 2 stroke
diesels are a figment of my imagination perhaps
Guy Fawkes
<chris....@cwfi.co.fk> wrote:
>
>> Would you like to explain how the change in air density increases the
>> compression ratio in an engine? And, assuming that both the sleeve and the
>> piston are iron/steel, that the gap between them will change given a
>> temperature change?
>
>The piston will not be iron/steel though will it? It will be made from the
>lightest strongest material available, some form of aluminium in a
>commercial engine.
yes,
1/ reduces reciprocating mass considerably
2/ absorbs more free electrons
down side is it contracts more than the steel liners when cold, hence
rings....
PyroJames
> On Tue, 14 Mar 2000 12:38:30 -0000, "PyroJames"
> <J.Ke...@SPAMcranfield.ac.uk> wrote:
>
> >
> >Guy,
>
> oh dear, here we go with the "i don't like fawkes cos he's rude so
> everything he says must be shit".....
No, not everything, just sometimes you can't debate without flaming and
turning the issue into one of parentage. I put in the "Guy" after the
initial composition, because it could have been read as though I was
addressing Ian.
>
> >Would you like to explain how the change in air density increases the
> >compression ratio in an engine?
>
> how can it fail to, a greater mass of denser cold air will fit into
> any given volume, say a cylinder bore at BDC, than the same volume of
> hot air,,,,,,,
>
I'd say that the compression ratio of an engine would be defined by the
reduction in volume of the cylinder due to the movement of the piston,
whether you put in hot air or cold air makes no difference. The reason that
intercoolers are put on turbo engines is to increase the charge density and
get a greater pressure increase after combustion, hence the reason that
turbo engines generally have a lower compression ratio than naturally
aspirated ones.
Any engineer will laugh at you if you say that a compression ratio in an
engine changes simple because of the gas you put in it.
> > And, assuming that both the sleeve and the
> >piston are iron/steel, that the gap between them will change given a
> >temperature change?
>
> when _was_ the last time you saw an iron piston..... _DO_ learn to
> think before trolling
>
Last time I had the head off my MD2B as I remember, although I could be
wrong. Assuming that it is aluminium, then it would suggest that in cold
weather the gap between the piston and the wall would increase thus making
the compression less and the engine harder to start?
Oh and by the way, I don't troll. It's just your limited powers of
perception that make you assume that anyone who dares to disagree with you,
must be a troll.
> >
> >Perhapes you would like to consider how an compression ignition engine
> >works, and how diesel is ignited?
>
> I do not have to consider it, I am on intimate terms with it. it's all
> heat of compression and flash point.
^^^^^^^^^^^^^^^^^^^^^
Exaclty, and this is likely to be lower in a cold climate and therefore make
a diesel more difficult to start under those circumstances.
"On intimate terms", consider the lack of detailed understanding that you
are showing, perhapes you should elaborate.
> > And perhapes why motors run better on a
> >wet day, but are not actually easier to start under those circumstances?
>
> they _are_ easier to start, unless they have a poorly maintained
> electrical system.....
You want to tell me that diesels rely on electricity to start, appart from
the starter motor obviously?
> >
> >Perhapes it might have something to do with vapourisation?
>
> fuck all to do with it, it _is_ all to do with free electrons, which
> is how the flame path spreads........
Yes, how the _flame_path_spreads_, or actually described as how the flame
kernal grows, as we are actually dealinng with a 3D system. _Ignition_
occurs in heated compressed vapour. A reduction in the heat in the cylinder
will limit the ease of ignition. Or would you like to tell me that diesel
actually burns as a liquid not a vapour.
And to sum it all up, why would Volvo-Penta put a "cold start" device on a
diesel if they are so much easier to start in cold damp weather? You do know
about cold start devices do you Guy? You do know how they work?
Guy Fawkes
<J.Ke...@SPAMcranfield.ac.uk> wrote:
>I'd say that the compression ratio of an engine would be defined by the
>reduction in volume of the cylinder due to the movement of the piston,
correct, i misread you and was addressing the issue of compression,
not CR
>Last time I had the head off my MD2B as I remember, although I could be
>wrong. Assuming that it is aluminium, then it would suggest that in cold
>weather the gap between the piston and the wall would increase thus making
>the compression less and the engine harder to start?
this doesn not contradict anything i said........
>
>Oh and by the way, I don't troll. It's just your limited powers of
>perception that make you assume that anyone who dares to disagree with you,
>must be a troll.
I don't assume it of everyone.
>Exaclty, and this is likely to be lower in a cold climate and therefore make
>a diesel more difficult to start under those circumstances.
>
>"On intimate terms", consider the lack of detailed understanding that you
>are showing, perhapes you should elaborate.
heat of compression, the amount by which air temperature is raised on
compression, in a well fettled engine intake air at 0 celsius as
opposed to intake air at 20 celsius will approximately equate to 20
degree lower peak compression temperature _in theory_, which isn't
enough to stop a well fettled motor from starting, add a worn motor,
and add the significant heat losses to the 0 degrees celsius metal of
the engine sleeves, piston and cylinder head and it can be enough....
hence 20 seconds of cranking is merely using heat of compression to
warm metal until heat of compression = flash point.
>> they _are_ easier to start, unless they have a poorly maintained
>> electrical system.....
>
>You want to tell me that diesels rely on electricity to start, appart from
>the starter motor obviously?
no, the starter is quite enough, why do you think diesels designed for
adverse conditions dont use small DC starters....
>Yes, how the _flame_path_spreads_, or actually described as how the flame
>kernal grows, as we are actually dealinng with a 3D system. _Ignition_
>occurs in heated compressed vapour. A reduction in the heat in the cylinder
>will limit the ease of ignition. Or would you like to tell me that diesel
>actually burns as a liquid not a vapour.
no, are you trying to tell _me_ that an injector will not atomise at
an ambient temperature of 0 celsius? or perhaps that flash point is
somehow altered????
>
>And to sum it all up, why would Volvo-Penta put a "cold start" device on a
>diesel if they are so much easier to start in cold damp weather?
ah yes, volvo-penta, one of the shoddier makes of diesel....
>You do know
>about cold start devices do you Guy? You do know how they work?
yes and yes, and you have to ask elsewhere why I get sarky.........
ok dipstick......
volvo penta generally do not use direct injection, which is one of the
many reasons they are crap.
volvo penta generally do not make inline fuel pumps, which is one of
the reasons they are crap
volvo penta generally do not make engines of bore and stroke
suffiecient to be classed as "real" diesels, which is one of the
reasons they are crap.
volvo penta used a lot of peugot traction diesels as their base, which
is one of the reasons they are crap.
volvo penta do not consider a fuel lift pump to be a service item, and
prefer to sell you a new one for 80 quid, which is one of the reasons
they are crap......
=====================
for the record I have used and worked on cellulose starters, hot bulb
starters, cartridge starters, air starters, donkey starters, I could
go on, but you get the picture.....
the BMC 2.2 had a cold start facility which consisted of an excess
fuel button on the pump, anything above waxing and the bitches would
start every time, but then it was a real engine, no cheap crap like
VP......
you will find that VP is often fitted as standard equipment for one
reason and one reason only, they are CHEAP, they are also crap.....
the honda SOHC 750 / 4 ran the camshaft without proper bearings, they
just line bored some ally billet and white metalled it, then the cams
blew it wasn't because of the power of the motor or rpm or anything
else, it's because it was cheap shit...
so to come back to your VP cold start device, it is fitted solely and
simply because the engine is not built properly in the first place.
if you examine a true marine diesel like perhaps a kelvin, you will
see the proof of what I am saying.
Rainer Thonnes
Guy Fawkes <guy.f...@error404.surfbaud.co.uk> writes:
>On Tue, 14 Mar 2000 12:38:30 -0000, "PyroJames"
><J.Ke...@SPAMcranfield.ac.uk> wrote:
>
>>Would you like to explain how the change in air density increases the
>>compression ratio in an engine?
>
>how can it fail to, a greater mass of denser cold air will fit into
>any given volume, say a cylinder bore at BDC, than the same volume of
>hot air,,,,,,,
I was under the impression that compression ratio is the ratio of
volume at BDC (call it V) to the volume at TDC (call it v). That
ratio (V/v) is the same (call it k) no matter what fills it.
Perhaps if you put in cold fog instead of just cold air, then given
the water droplets don't compress, you will indeed get a slightly
higher compression ratio for the gas, as a result of having subtracted
a constant amount of volume (call it w). (V-w)/(v-w) > k if k>1.
But you didn't mean that, did you?
> it _is_ all to do with free electrons, which
>is how the flame path spreads........
I take it back, you're not Cap'n Neal. He wouldn't make brilliant
jokes like that. Free electrons, flame paths, you're obviously
referring to the spreading of Usenet flames being enhanced by the
use of Internet access which is not paid for at point of use.
PyroJames
> On Wed, 15 Mar 2000 09:59:17 -0000, "PyroJames"
> <J.Ke...@SPAMcranfield.ac.uk> wrote:
>
> >Last time I had the head off my MD2B as I remember, although I could be
> >wrong. Assuming that it is aluminium, then it would suggest that in cold
> >weather the gap between the piston and the wall would increase thus
making
> >the compression less and the engine harder to start?
>
> this doesn not contradict anything i said........
Except that in cold weather the engine will be harder to start.
>
> >
> >Oh and by the way, I don't troll. It's just your limited powers of
> >perception that make you assume that anyone who dares to disagree with
you,
> >must be a troll.
>
> I don't assume it of everyone.
Why assume it of me. What was the troll in my arguement. Did I throw in a
stupid comment and dissappear, did I flame someone with no reason? I think
not.
> >Exaclty, and this is likely to be lower in a cold climate and therefore
make
> >a diesel more difficult to start under those circumstances.
> >
> >"On intimate terms", consider the lack of detailed understanding that you
> >are showing, perhapes you should elaborate.
>
> heat of compression, the amount by which air temperature is raised on
> compression, in a well fettled engine intake air at 0 celsius as
> opposed to intake air at 20 celsius will approximately equate to 20
> degree lower peak compression temperature _in theory_, which isn't
> enough to stop a well fettled motor from starting, add a worn motor,
> and add the significant heat losses to the 0 degrees celsius metal of
> the engine sleeves, piston and cylinder head and it can be enough....
So an engine may be harder to start cold? We never said that we had to be
dealing with an engine in perfect condition.
>
> hence 20 seconds of cranking is merely using heat of compression to
> warm metal until heat of compression = flash point.
>
Yes. Warm the engine up and it will start. Seems to suggest that if it is
colder to start with, you will have to heat it more and it will take longer,
and to all intensive purposes is harder to start.
> >Yes, how the _flame_path_spreads_, or actually described as how the flame
> >kernal grows, as we are actually dealinng with a 3D system. _Ignition_
> >occurs in heated compressed vapour. A reduction in the heat in the
cylinder
> >will limit the ease of ignition. Or would you like to tell me that diesel
> >actually burns as a liquid not a vapour.
>
> no, are you trying to tell _me_ that an injector will not atomise at
> an ambient temperature of 0 celsius? or perhaps that flash point is
> somehow altered????
Again you assume that the injectors are in perfect condition to achieve
atomisation, if they are not vapourisation is an issue.
> >And to sum it all up, why would Volvo-Penta put a "cold start" device on
a
> >diesel if they are so much easier to start in cold damp weather?
>
> ah yes, volvo-penta, one of the shoddier makes of diesel....
>
First time I've heard that.
> >You do know
> >about cold start devices do you Guy? You do know how they work?
>
> yes and yes, and you have to ask elsewhere why I get sarky.........
>
> ok dipstick......
Such control, so eloquent.
>
> volvo penta generally do not use direct injection, which is one of the
> many reasons they are crap.
>
Mine does. Perhapes you are thinking of the newer VP made by Perkins, I
don't know.
> volvo penta generally do not make inline fuel pumps, which is one of
> the reasons they are crap
>
> volvo penta generally do not make engines of bore and stroke
> suffiecient to be classed as "real" diesels, which is one of the
> reasons they are crap.
I see. The only engines you want to consider for this discussion of why they
may or may not be harder to start cold, are new engines of a specific
bore/stroke. Maybe this doesn't relate to the general level of interest
here. Maybe we do have old engines, maybe they are VP and others not deigned
by you to be "real" deisels. Maybe you should consider who is reading this.
>
> for the record I have used and worked on cellulose starters, hot bulb
> starters, cartridge starters, air starters, donkey starters, I could
> go on, but you get the picture.....
>
> the BMC 2.2 had a cold start facility which consisted of an excess
> fuel button on the pump, anything above waxing and the bitches would
> start every time, but then it was a real engine, no cheap crap like
> VP......
Sound exactly the same as the cold start on mine, and yes it does start it
every time. I use it when it is cold, because we all know that when it's
cold it's harder to start.
So VP recognise it, BMC (by your above example) recognise it, the fact that
you have just listed a whole range of cold start devices would
overwhelmingly suggest that cold starting is more difficult. I think I rest
my case.
>
> you will find that VP is often fitted as standard equipment for one
> reason and one reason only, they are CHEAP, they are also crap.....
>
> the honda SOHC 750 / 4 ran the camshaft without proper bearings, they
> just line bored some ally billet and white metalled it, then the cams
> blew it wasn't because of the power of the motor or rpm or anything
> else, it's because it was cheap shit...
OT OT OT
Ian Sandell
<phi...@turgoose.freeserve.co.uk> wrote:
Impeccable logic. Why isn't this included in those logic trees?
Jean thinks it is a much better idea than me grubbing around up to my
eblows in grease and oil (she asks are there any Neked Meen ?) Just a
bit far to go for a weekend sail.
Ian
>My guess would be it is cold. What I mean is I bet it starts a lot better in
>June July than it does in February?
>The air is cold and damp and that is what enters the air intake along with
>any
>condensation already inside.
Geoff Blake
: On Wed, 15 Mar 2000 09:59:17 -0000, "PyroJames"
: <J.Ke...@SPAMcranfield.ac.uk> wrote:
: >Last time I had the head off my MD2B as I remember, although I could be
: >wrong. Assuming that it is aluminium, then it would suggest that in cold
: >weather the gap between the piston and the wall would increase thus making
: >the compression less and the engine harder to start?
: this doesn not contradict anything i said........
I would think it extremely unlikely that the change in piston clearance
would have any significant bearing on the lack of starting.
: >Exaclty, and this is likely to be lower in a cold climate and therefore make
: >a diesel more difficult to start under those circumstances.
: >
: >"On intimate terms", consider the lack of detailed understanding that you
: >are showing, perhapes you should elaborate.
: heat of compression, the amount by which air temperature is raised on
: compression, in a well fettled engine intake air at 0 celsius as
: opposed to intake air at 20 celsius will approximately equate to 20
: degree lower peak compression temperature _in theory_, which isn't
: enough to stop a well fettled motor from starting, add a worn motor,
: and add the significant heat losses to the 0 degrees celsius metal of
: the engine sleeves, piston and cylinder head and it can be enough....
: hence 20 seconds of cranking is merely using heat of compression to
: warm metal until heat of compression = flash point.
Thus making up for slow cranking. It is *easy* to start diesels at -40 deg,
providing that the fuel is still fluid enough to be injected and the
cranking speed is fast enough.
: no, the starter is quite enough, why do you think diesels designed for
: adverse conditions dont use small DC starters....
'cos they crank too slowly. Low temperature starters frequently use one of
small petrol engines, large springs (packs of belville washers under
compression) or compressed air.
: >Yes, how the _flame_path_spreads_, or actually described as how the flame
: >kernal grows, as we are actually dealinng with a 3D system. _Ignition_
: >occurs in heated compressed vapour. A reduction in the heat in the cylinder
: >will limit the ease of ignition. Or would you like to tell me that diesel
: >actually burns as a liquid not a vapour.
: no, are you trying to tell _me_ that an injector will not atomise at
: an ambient temperature of 0 celsius? or perhaps that flash point is
: somehow altered????
It always appeared to me that diesel burnt as atomised droplets.
: >
: >And to sum it all up, why would Volvo-Penta put a "cold start" device on a
: >diesel if they are so much easier to start in cold damp weather?
I don't know Volvo Penta, as Guy would say I have only dealt with real
diesels (like AEC, Dorman, Gardeners, Leyland, Listers, (old) Perkins,
Rustons, etc). But do they have a real cold start device?
: ah yes, volvo-penta, one of the shoddier makes of diesel....
: >You do know
: >about cold start devices do you Guy? You do know how they work?
: yes and yes, and you have to ask elsewhere why I get sarky.........
: ok dipstick......
: volvo penta generally do not use direct injection, which is one of the
: many reasons they are crap.
Indirect (Ricardo Chamber) injection engines run quieter and are applicable
to engines below about 1 litre/cylinder. They also have a significantly
greater heat loss and are thus more difficult to start, particularly when
cold. Some form of pre-heat is almost mandatory.
: volvo penta generally do not make inline fuel pumps, which is one of
: the reasons they are crap
Inline pumps, one of the marke of a true diesel.
: volvo penta generally do not make engines of bore and stroke
: suffiecient to be classed as "real" diesels, which is one of the
: reasons they are crap.
BIG engines, doing a maximum of around 1,000 to 2,500 rpm....
: volvo penta used a lot of peugot traction diesels as their base, which
: is one of the reasons they are crap.
Some Pug diesels are quite good, expecially the XU8A in my car...
: volvo penta do not consider a fuel lift pump to be a service item, and
: prefer to sell you a new one for 80 quid, which is one of the reasons
: they are crap......
Bot a skilled practicioner can rebuild a lift pump from bits, and many of
those bits are quite common. (I once rebuilt a LandRover diesel lift pump
from a Triumph 200 petrol engine lift pump (in France where spares were not
readily available)).
: =====================
: for the record I have used and worked on cellulose starters, hot bulb
: starters, cartridge starters, air starters, donkey starters, I could
: go on, but you get the picture.....
: the BMC 2.2 had a cold start facility which consisted of an excess
: fuel button on the pump, anything above waxing and the bitches would
: start every time, but then it was a real engine, no cheap crap like
: VP......
Hear hear...
: you will find that VP is often fitted as standard equipment for one
: reason and one reason only, they are CHEAP, they are also crap.....
: the honda SOHC 750 / 4 ran the camshaft without proper bearings, they
: just line bored some ally billet and white metalled it, then the cams
: blew it wasn't because of the power of the motor or rpm or anything
: else, it's because it was cheap shit...
: so to come back to your VP cold start device, it is fitted solely and
: simply because the engine is not built properly in the first place.
: if you examine a true marine diesel like perhaps a kelvin, you will
: see the proof of what I am saying.
Or a Doxford, or a MAN or a Deutz or a .....
Guy Fawkes
Blake) wrote:
>I don't know Volvo Penta, as Guy would say I have only dealt with real
>diesels (like AEC, Dorman, Gardeners, Leyland, Listers, (old) Perkins,
>Rustons, etc). But do they have a real cold start device?
music to my ears
>Indirect (Ricardo Chamber) injection engines run quieter and are applicable
>to engines below about 1 litre/cylinder. They also have a significantly
>greater heat loss and are thus more difficult to start, particularly when
>cold. Some form of pre-heat is almost mandatory.
in short, they are crap, remember the dreadful fudge that was the
watermota 1600 ford petrol to diesel conversion.........
>BIG engines, doing a maximum of around 1,000 to 2,500 rpm....
nah, BIG motors do 350 rpm, one loss I regret is a photgraph of 4 of
us sat with cans of beer inside the bore of a big vertical opposed
piston electric blower fiat... even seen the tappet clearances done
while running with a big flogging wrench and sledges, danger moneY?
wots that?
>Bot a skilled practicioner can rebuild a lift pump from bits, and many of
>those bits are quite common. (I once rebuilt a LandRover diesel lift pump
>from a Triumph 200 petrol engine lift pump (in France where spares were not
>readily available)).
yes, but my point was that any company that _made_ a lift pump as a
non-service item is clearly crap.
>Or a Doxford, or a MAN or a Deutz or a .....
cat, gardner semi-diesel, maybach, fiat, lis blackstones, or those
made-out-of-lumps-of-slag things used in norwegian fishing boats......
but NOT MTU or detroit or nanni or ruggerini or baby perkins....
Devang Rathod
We have ready stock of following items:
Big End Bearings
DV20 Piston
Main Bearings and Bushings Set Liners, (Set of 2 Bush and intermediate Brg)
Inlet & Exhaust Valve & Guide
Inlet & Exhaust Valve spring, Cap, Valve Seat.
Gasket Set 032D4201 with or without Oil seals and washers
oil seals set of 2 PC Only, Also Old Lub pump oil seal old type available
copper washer, O-rings (common to dv24)
You can also purchase directly from our webstore
Web store - https://devprecisionengineers.co.uk/product-category/bukh-dv20/
Thanking you in the mean time.
Best Regards
Devang Rathod
Dev Precision Engineers
"ASHUTOSH" 4th Floor, Jagnath Plot,
Gymkhana Main Rd., Nr. Street 6,
Rajkot - 360 001 (GUJ) INDIA
MOBILE - +91 98795-74372
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An ISO 9001:2015 Certified Company
Website - https://devprecisionengineers.com
Webstore - https://devprecisionengineers.co.uk/
On Saturday, March 11, 2000 at 1:30:00 PM UTC+5:30, Ian Sandell wrote:
> I have a Bukh 20 which runs fine but is a bugger to start. It has no
> cold start device but the manual refers to a Thermostart Valve (?) as
> a optional extra. The compression seems good (but not measured) and
> the head and injectors have recently been overhauled.
> Does anyone have experience of Bukhs?
Vir Campestris
> Dear Sir
>
> We have ready stock of following items:
> Big End Bearings
> DV20 Piston
> Main Bearings and Bushings Set Liners, (Set of 2 Bush and intermediate Brg)
> Inlet & Exhaust Valve & Guide
> Inlet & Exhaust Valve spring, Cap, Valve Seat.
> Gasket Set 032D4201 with or without Oil seals and washers
> oil seals set of 2 PC Only, Also Old Lub pump oil seal old type available
> copper washer, O-rings (common to dv24)
>
> You can also purchase directly from our webstore
>
> Thanking you in the mean time.
>
> Best Regards
> Devang Rathod
>
> On Saturday, March 11, 2000 at 1:30:00 PM UTC+5:30, Ian Sandell wrote:
>> I have a Bukh 20 which runs fine but is a bugger to start. It has no
>> cold start device but the manual refers to a Thermostart Valve (?) as
>> a optional extra. The compression seems good (but not measured) and
>> the head and injectors have recently been overhauled.
>> Does anyone have experience of Bukhs?
>> Ian
notice that the engine hasn't started for nearly 23 years...
Andy