Diesel engine cars

Some engines have 'glow plugs',  these protrude into each combustion chamber.  Others have preheater elements than heat the air in the inlet manifold prior to the first engine rotation start.    Most modern engines control the start sequence with the EMC,  mine only preheats for a second or so when its around/below freezing,  noticeable by the extra second or so the autostart takes when cold.      I'm not aware of any halfway modern engine that needs extra heat once its up & firing,  unlike the bad old days.

The Akroyd Stuart engine had low compression that did not have the ability to get enough heat from compression alone,  he developed 'hot bulb' method for vaporising a kerosene type of fuel.   He joined with others over time in different developments with some/most moving on to do there own thing.          Various improvements were made & that type of engine from different designers continued into the 1920's,   I have one in a workshop that we (one of my other hobbies) use,  we need to decide on scrap or restore,  the engine starts on petrol & once the exhaust to inlet heat exchange vaposer is up to temp,  it runs on kerosene/paraffin.

A real step forward with modern fuel-injected, computer-controlled cars is the instant start and instant power of ICEs. Remember the bad-old-days of having to idle them interminably before you could drive off?

In Canada,/USA, Mazda seem to be moving ahead of others  in the 2018 crowded mid-sized SUV segment with a new CX-5 2.2-Litre Skyactiv-D turbodiesel. It has 150 hp and 280 lb.-ft of torque. They reduced emissions of the diesel engine by lowering the compression ratio. That will teach you VW !

Blimey, Mazda, underachieving!

my seven year old 2.1 Merc has 201bhp and 368ft.lb...

Our Diesel always travels in a crate.

Diesel being the name of our Cairn Terrier.

G

Does he smoke?

GraemeH posted:

Our Diesel always travels in a crate.

Diesel being the name of our Cairn Terrier.

Nyssa and Adric don’t travel in a crate, but Adric goes to his crate at night to sleep without any forcing him.

Tony Lockhart posted:

Does he smoke?

Let’s just say the ‘emissions’ are not doing the ozone any good.

G

Tony Lockhart posted:

Blimey, Mazda, underachieving!

 

my seven year old 2.1 Merc has 201bhp and 368ft.lb...

Problem is ( even if I could afford it) ) Mercedes do not offer any diesels anymore in USA/CAN.  

Tony Lockhart posted:

As far as I'm aware, modern Diesel engines, maybe since the DPF was introduced, have glow plugs that might stay on for a few minutes after engine start. This is to burn of the nasties that might clog the DPF prematurely and give cleaner emissions. There'll be no light on the dash to indicate this. 

 

Also, modern Diesel engines can have pressure sensors built into their glow plugs, thus giving the 'closed loop' that Diesels haven't had in the past.  

Mike-B posted:

Some engines have 'glow plugs',  these protrude into each combustion chamber.  Others have preheater elements than heat the air in the inlet manifold prior to the first engine rotation start.    Most modern engines control the start sequence with the EMC,  mine only preheats for a second or so when its around/below freezing,  noticeable by the extra second or so the autostart takes when cold.      I'm not aware of any halfway modern engine that needs extra heat once its up & firing,  unlike the bad old days.

The Akroyd Stuart engine had low compression that did not have the ability to get enough heat from compression alone,  he developed 'hot bulb' method for vaporising a kerosene type of fuel.   He joined with others over time in different developments with some/most moving on to do there own thing.          Various improvements were made & that type of engine from different designers continued into the 1920's,   I have one in a workshop that we (one of my other hobbies) use,  we need to decide on scrap or restore,  the engine starts on petrol & once the exhaust to inlet heat exchange vaposer is up to temp,  it runs on kerosene/paraffin.

When an Akroyd Stuart engine (aka a "Diesel" engine) is in running condition (i.e. after the glowplugs or preheat chamber are initially electrically heated) the glowplugs or a passive heat storage element are kept hot by the combustion process...  Exactly what actually happened in the Akroyd Stuart engine: using the stored heat to lift part of the charge to a temperature where the (lower) compression could ignite it.

So yes, with a Stuart engine, the external heating (electric in more recent - i.e. non vintage models) is not needed off after the starting phase (either immediately or after a short period of running according to the design) and the stored heat then maintains the conditions for ignition with compression providing the heat impulse to trigger the ignition.

Akroyd Stuart invented that type of engine and Rudolph Diesel (among other as you so rightly point out) developed a variant solely using the heat derived from compression to initiate combustion.  He could do this because of the much more sophisticated machine tools that became available early in the 20th century allowing much higher compression ratios.  To name this family of engines after Diesel (and hence credit him with the invention of the engine type) is to do a disservice to Stuart.

In that case, calling it a Stuart engine does a disservice to all the inventors of other tech that Stuart used. 

It isn't important. The world and his dog calls them Diesel engines. You call them Stuarts if you want, but make sure I'm nowhere near you, as I struggle to cope with embarrassment.  

Call them whatever you like, but the political world regards them as evil which must be taxed off the roads.  Manufacturers are in the process of responding and I suspect within 5 years buying a new diesel powered car will be a very rare behaviour in UK.

Peter

northpole posted:

Call them whatever you like, but the political world regards them as evil which must be taxed off the roads.  Manufacturers are in the process of responding and I suspect within 5 years buying a new diesel powered car will be a very rare behaviour in UK.

Peter

It's easy to dismiss a push-back against ICE-powered cars as "political" but less easy to dismiss the extensive epidemiology that links the emissions from our vehicles to poor health outcomes and reduced lifespans for city dwellers.

More on emissions. Some independent results.

http://equaindex.com/

Interestingly, Don's C-series diesel Mercedes rates in the worst category as an "H" at 12X the current euro-6 standards (as did our previous X5)...

And a very wordy BBC article that really struggles to get to the point.

http://www.bbc.co.uk/news/reso..._is_your_car_exhaust

Tony Lockhart posted:

In that case, calling it a Stuart engine does a disservice to all the inventors of other tech that Stuart used.

 It isn't important. The world and his dog calls them Diesel engines. You call them Stuarts if you want, but make sure I'm nowhere near you, as I struggle to cope with embarrassment.  

Maybe i’m one of a few around these parts that have worked with,  cajoled & cursed at one or other of the derivatives of them,  call them whatever you like,   give me a real diesel any day,  woof woof 

Wicky

My beef is not to keep Diesel engined vehicles; more, it relates to the government misinformation which promoted them in the first place and prematurely killed off petrol lean burn development by major motor manufacturers back in the day.  That, plus perhaps more seriously, the lack of strong indicators that all the other pollutant discharging sources within cities are being afforded such attention.  No doubt because they would require more government rather than Joe Public digging into their pockets to fund a really significant improvement.

What I also find particularly galling is the London road network introducing bus and cycle lanes and re-engineered layouts which appear to have created significant bottle necks leaving very long queues of near stationary traffic.  Traffic which I can’t help think is discharging higher concentrations of pollution than before.  Simply increasing congestion charge tariffs makes little or no difference other than to the coffers of local authorities - the traffic remains.

My perspective is from that of a commuting cyclist.

Peter

Like everything else the problem Is human over population. We can only hope to slow the rate we destroy the planet and ourselves.

I've read that the world's population will be going down by the end of the century.  Families in Africa and Asia are getting drastically smaller generally and in a generation or two this will nullify the effect of people living longer.  

The world will be a very very strange place.  

Tony Lockhart posted:

I've read that the world's population will be going down by the end of the century.  Families in Africa and Asia are getting drastically smaller generally and in a generation or two this will nullify the effect of people living longer.  

 

The world will be a very very strange place.  

This is good and may back up your view Tony:

https://www.ted.com/talks/hans...al_population_growth

G

GraemeH posted:

Tony Lockhart posted:

I've read that the world's population will be going down by the end of the century.  Families in Africa and Asia are getting drastically smaller generally and in a generation or two this will nullify the effect of people living longer.  

 

The world will be a very very strange place.  

This is good and may back up your view Tony:

https://www.ted.com/talks/hans...al_population_growth

G

Pretty much what I've seen and read. One article projected to 2100, and the population was falling from a peak of 11bn. 

GraemeH posted:

Tony Lockhart posted:

I've read that the world's population will be going down by the end of the century.  Families in Africa and Asia are getting drastically smaller generally and in a generation or two this will nullify the effect of people living longer.  

 

The world will be a very very strange place.  

This is good and may back up your view Tony:

https://www.ted.com/talks/hans...al_population_growth

G

Interesting article and simply explained.  

northpole posted:

Wicky

My beef is not to keep Diesel engined vehicles; more, it relates to the government misinformation which promoted them in the first place and prematurely killed off petrol lean burn development by major motor manufacturers back in the day.  That, plus perhaps more seriously, the lack of strong indicators that all the other pollutant discharging sources within cities are being afforded such attention.  No doubt because they would require more government rather than Joe Public digging into their pockets to fund a really significant improvement.

What I also find particularly galling is the London road network introducing bus and cycle lanes and re-engineered layouts which appear to have created significant bottle necks leaving very long queues of near stationary traffic.  Traffic which I can’t help think is discharging higher concentrations of pollution than before.  Simply increasing congestion charge tariffs makes little or no difference other than to the coffers of local authorities - the traffic remains.

My perspective is from that of a commuting cyclist.

Peter

Pitar,

Yes the UK government (and others) screwed the pooch on the misguided encouragement of diesels. Seems obvious with hindsight that considering the effects of all tailpipe emissions would have been a better policy. I think people who purchased diesels on the basis of reduced emissions have a right to be aggrieved. Many purchased on the basis of lower running cost, and those people perhaps have less to complain about, except the moving goal posts.

I terms of city congestion, road design in inner cities is not really intended to ease congestion, but to discourage driving. Causing/allowing congestion is actually one way of doing this. I know congestion discourages me from driving, and I make far fewer trips in the car than I would if traffic was free flowing (and that's in Vancouver, a city that does not really have much congestion at all). Yes the emissions in stalled traffic on a per vehicle-km driven basis may be higher, but total emissions may be lower due to the reduced number of vehicle trips taken.

Congested traffic is also safer for vulnerable road users due to the slower speeds. The current term used for roadway modification to reduce speeds is "road dieting". I am in a running battle with our council to ensure that road dieting implementation does not make things more dangerous for cyclists and pedestrians. Some of their implementation is appalling in this respect.

The issue of using/allowing congestion (it inevitably becomes the default limit no matter what you do, once demand for roads reaches a certain level) to control behaviour is that it is very inefficient. The externalised costs/impact of my decision to drive on the journey time of others is not something I really consider. But I am at the mercy of others' decisions to drive in terms of their impact on my journey times. We're all negatively affected by each others' decisions to drive. It's a variation of the "tragedy of the commons" effect.

Road pricing, while generally unpopular (so are traffic jams), is an overall much-more efficient system for allocating the scarce resource of city (and other busy) roads. And congestion charges do inevitably work if they are high enough. There is an issue where we can get to point that "only the rich can drive" but that's a whole other issue within the greater discussion on income and wealth inequality. Only the rich can take private planes, too.

The last time I checked my car actual average consumption is when stuck in traffic at 7 km/h.  The computer indicated 12l/100km instead of  4.3l/100km when driving at 100 km/h so congestion is very bad for the environment when you consider that millions of car are stuck in traffic everyday.

winkyincanada posted:

northpole posted:

Wicky

My beef is not to keep Diesel engined vehicles; more, it relates to the government misinformation which promoted them in the first place and prematurely killed off petrol lean burn development by major motor manufacturers back in the day.  That, plus perhaps more seriously, the lack of strong indicators that all the other pollutant discharging sources within cities are being afforded such attention.  No doubt because they would require more government rather than Joe Public digging into their pockets to fund a really significant improvement.

What I also find particularly galling is the London road network introducing bus and cycle lanes and re-engineered layouts which appear to have created significant bottle necks leaving very long queues of near stationary traffic.  Traffic which I can’t help think is discharging higher concentrations of pollution than before.  Simply increasing congestion charge tariffs makes little or no difference other than to the coffers of local authorities - the traffic remains.

My perspective is from that of a commuting cyclist.

Peter

Pitar,

Yes the UK government (and others) screwed the pooch on the misguided encouragement of diesels. Seems obvious with hindsight that considering the effects of all tailpipe emissions would have been a better policy. I think people who purchased diesels on the basis of reduced emissions have a right to be aggrieved. Many purchased on the basis of lower running cost, and those people perhaps have less to complain about, except the moving goal posts.

As I mentioned, it is the lack of aggressive focus on other significant pollution generators eg commercial lorries, buses, taxis, trains by government which is unbalanced if they are serious about addressing polution esp in cities.

I terms of city congestion, road design in inner cities is not really intended to ease congestion, but to discourage driving. Causing/allowing congestion is actually one way of doing this. I know congestion discourages me from driving, and I make far fewer trips in the car than I would if traffic was free flowing (and that's in Vancouver, a city that does not really have much congestion at all). Yes the emissions in stalled traffic on a per vehicle-km driven basis may be higher, but total emissions may be lower due to the reduced number of vehicle trips taken.

Try explaining that to the lady I came across a few months back who lives in an area of London called Archway beside one of the main roads out of the city centre.  She was adamant that since the road remodelling around Archway, her asthma has become much worse.  These are real world consequences of traffic engineering and I'm afraid that traffic volumes in the centre of London, certainly around me, have not decreased at all.  London workers appear immune to pricing, road engineering, speed limits reduced to 20mph.  The only thing which i think would reduce traffic is an electronic control mechanism banning non essential users from the inner London roads.  Same in other major conurbations.

Congested traffic is also safer for vulnerable road users due to the slower speeds. The current term used for roadway modification to reduce speeds is "road dieting". I am in a running battle with our council to ensure that road dieting implementation does not make things more dangerous for cyclists and pedestrians. Some of their implementation is appalling in this respect.

Can't disagree with the comment on poor implementation and increased dangers which often appear to result - perhaps in part because the motorists themselves become frustrated by some of the barmy measures being forced on them.  This seems to make road junctions even more dangerous places for cyclists and pedestrians as drivers jockey to gain first place during the switch from two lanes to a bottlenecked one lane.  I'm seeing less tolerance than ever.  I also see more speed jockeys driving along my road which is often used as a rat run.  It's a 20mph limit with 'traffic calming' ramps however, some folks in their extremely powerful sports vehicles seem to just go nuts all too often accelerating flat out to red line cut off in first & second gear before braking sharply for the next ramp.  Has to be seen to be believed and is hyper dangerous for everyone else on the road or footpath.  So perhaps not in agreement with road dieting....

The issue of using/allowing congestion (it inevitably becomes the default limit no matter what you do, once demand for roads reaches a certain level) to control behaviour is that it is very inefficient. The externalised costs/impact of my decision to drive on the journey time of others is not something I really consider. But I am at the mercy of others' decisions to drive in terms of their impact on my journey times. We're all negatively affected by each others' decisions to drive. It's a variation of the "tragedy of the commons" effect.

Road pricing, while generally unpopular (so are traffic jams), is an overall much-more efficient system for allocating the scarce resource of city (and other busy) roads. And congestion charges do inevitably work if they are high enough. There is an issue where we can get to point that "only the rich can drive" but that's a whole other issue within the greater discussion on income and wealth inequality. Only the rich can take private planes, too.

Have to completely disagree with you here on the basis of behaviours in London.  The business drivers simply pay more and add the costs to their expenses.  They mostly drive into and out of town.  Within the congestion zone hoewever, you find a huge diversity of people and incomes.  Working class folks with families are the ones who feel the need to drive their kids to and from school.  You can argue that they don't need to do this however, there is such paranoia these days about dangers to children, that until such times as these sociological concerns/ behaviours are addressed, parents will continue to feel compelled to drive in town.  They simply cannot afford to do so.  Back to my concern that much greater intelligence is needed to control traffic volumes - a simple pricing policy in a city with a working population as extraordinarily rich as London will achieve very little, other than help fund local authorities' budget coffers. Braver, stronger, more clever measures are urgently required to truly help our air quality.

Peter

winkyincanada posted:

northpole posted:

Call them whatever you like, but the political world regards them as evil which must be taxed off the roads.  Manufacturers are in the process of responding and I suspect within 5 years buying a new diesel powered car will be a very rare behaviour in UK.

Peter

It's easy to dismiss a push-back against ICE-powered cars as "political" but less easy to dismiss the extensive epidemiology that links the emissions from our vehicles to poor health outcomes and reduced lifespans for city dwellers.

Move to the countryside. We live part-time up on the ridge between Vernon and Kelowna and our daughter lives out of town towards Lumby.

Ok, I imagine the prevailing westerly wind brings the contamination from your emissions in our direction, and we certainly recognised the smoke from widespread wildfire this summer, But I recon we are better off than living/working/cycling  in virtually any part of Vancouver.