What Do You Guys Think About This Vid?

[FalcoColumbarius]

What do you think about this video?
Can we have a discussion, please?



Falco.

[Mephisto]

All true information, but, most of it does not apply to diesels. Number one, diesels are supposed to run lean so this is not an issue. Number two, most of the environmentally unfriendly gasses are formed at higher cylinder temps, diesels have much lower cylinder temps than gassers (at least for the most part) so unless you're really beatin the thing you aren't creating most of the unfriendlies. It's just like when they first started putting catalytic converters on diesels which don't usually have the EGTs to light off the catalyst making the cat useless the majority of the time, on top of that the cat would clog up faster with the diesel particulate making the cat an even larger restriction, at least this sreved to raise EGTs a little, lol. They have at least figured that one out now and make an ammonia based catalyst for diesels (thanks to honda) that lights off at a much lower temp. As I have said before, question everything, this is merely my understanding of it and I am well aware that people can interpret the same thing in a very different manner.



Sorry, hands were typing and the brain was in neutral. Edit = Cylinder temps are much lower as diesels are always running lean, the closer they are to stoich the hotter they are, so at stoich the cylinder temps would be higher but since diesels will basically never reach this point the cylinder temps are much lower unless of course you have your fuel turned up and are working it extremely hard. Thanks Falco for questioning me, lol, just as I had asked.

[FalcoColumbarius]

So... combustion still requires oxygen, no? Is that not why we have the turbo? Would not the CO2 starve the cylinder of some of the oxygen, causing the combustion to burn cooler which would explain the black soot from unburned fuel coming out the tail pipe, no? Also, one of the big selling points I have heard over the last couple of years is that because diesels run hotter (due to compression over spark) they are built better, therefore more likely to last longer. I would think that a compressed oil would have to burn hotter than a solvent getting a spark............

Falco.

[Modsqwad]

Our egr's are there to reduce NOX emissions. The guy in the video pegged it right on. It doesn't help our engine one bit (lowers power output actualy) but is there to lower emissions nothing more. On an older engine like ours with no working catalyst it probably does more harm than good. I say block it off and be done with it. This quote is from Wikipedia and covers it better
than me.
Andy Wilson


In modern diesel engines, the EGR gas is cooled through a heat exchanger to allow the introduction of a greater mass of recirculated gas. Unlike SI engines, diesels are not limited by the need for a contiguous flamefront; furthermore, since diesels always operate with excess air, they benefit from EGR rates as high as 50% (at idle, where there is otherwise a very large amount of excess air) in controlling NOx emissions.
Since diesel engines are unthrottled, EGR does not lower throttling losses in the way that it does for SI engines (see above). However, exhaust gas (largely carbon dioxide and water vapor) has a higher specific heat than air, and so it still serves to lower peak combustion temperatures. There are trade offs however. Adding EGR to a diesel reduces the specific heat ratio of the combustion gases in the power stroke. This reduces the amount of power that can be extracted by the piston. EGR also tends to reduce the amount of fuel burned in the power stroke. This is evident by the increase in particulate emissions that corresponds to an increase in EGR. Particulate matter (mainly carbon) that is not burned in the power stroke is wasted energy. Stricter regulations on particulate matter(PM) call for further emission controls to be introduced to compensate for the PM emissions introduced by EGR. The most common is particulate filters in the exhaust system that result in reduced fuel efficiency. Since EGR increases the amount of PM that must be dealt with and reduces the exhaust gas temperatures and available oxygen these filters need to function properly to burn off soot, automakers have had to consider injecting fuel and air directly into the exhaust system to keep these filters from plugging up.
[edit]EGR deletion
EGR deletion in diesel engines is considered justifiable by a wide range of people, including the environmentally conscious. Although deleting the EGR system results in increased NOx level hydrocarbon emissions, Particulates, Carbon monoxide and Carbon dioxide are drastically reduced. Furthermore, EGR deletion results in an increase in fuel economy as high as 25%. Exhaust gas recirculated back into the cylinders adds wear-inducing contaminants and causes an increase engine oil acidity, which can result in an inefficient, poorly running engine. The increased level of soot also creates the need for diesel particulate filters to prevent environmental contamination.

[fexlboi]

I say block it off and be done with it.

... and so I did this week http://dinoevo.de/2010/04/egr-removed/

[Jsq]

I'm probably going to go ahead and remove my EGR but i'm not 100% on the pyro mod. Just wondering if any one has personal experience with damaging their turbo from overheating? My mechanic said that I've got no hope in hell of cooking my turbo because my engine has such low horsepower. I like the idea of using the pyro to extend my engine life but is it truly necessary and worth the money? Any first hand experience regarding a turbo meltdown/replacement would be greatly appreciated. I realise that a couple hundred dollars of prevention is better than a seven hundred dollar repair but if it has never actually happened on a Delica I'll put my money into other preventative upgrades.

Thank you all in advance

[fexlboi]

I'm probably going to go ahead and remove my EGR but i'm not 100% on the pyro mod. Just wondering if any one has personal experience with damaging their turbo from overheating?

A pyro is actually more to prevent any craked heads which is common with this engines if you overhead it. To avoid a turbo meltdown, just don't turn off your engine after you pushed it. Let it idle for a while.

[Mephisto]

I was unaware that the specific heat characteristics of the exhaust gas allowed it to absorb more latent heat thus reducing cylinder temps, interesting, thanks for that tid-bit, Andy.

[Green1]

[quote="FalcoColumbarius"one of the big selling points I have heard over the last couple of years is that because diesels run hotter (due to compression over spark) they are built better, therefore more likely to last longer.[/quote]
Diesels are built stronger not so much because of temperature differences but because they work at a much higher compression than gas (more force to the explosions). I have not compared specific numbers for gas vs diesel, but my understanding has always been that despite the compression vs spark, that diesels generally still run cooler than gas engines. (not that I would touch either one with my bare hand immediately after a long highway run...)

[Tinytoy]

Forgive me if I'm wrong but doesn't a diesel engine work by compressing the air, which causes heat ,that then causes the diesel which is injected to spontaneously combust? Doesn't diesel have a higher flashpoint than gasoline?

[Jsq]

A pyro is actually more to prevent any craked heads which is common with this engines if you overhead it. To avoid a turbo meltdown, just don't turn off your engine after you pushed it. Let it idle for a while.

Just how common of a problem is overheating with the Delicas? Is it common to overheat from pushing it too hard or more commonly caused by lack of attention to the cooling system?

[Green1]

Just how common of a problem is overheating with the Delicas? Is it common to overheat from pushing it too hard or more commonly caused by lack of attention to the cooling system?

The 2 are related. If your cooling system sucks, then it overheats easily, if your cooling system is good, then it's much harder to overheat.
Most importantly perhaps though is that if your cooling system sucks too badly (as in completely clogged so there's no flow) the coolant sensor on the dash board can read quite low until it's way too late to do anything, whereas a pyro will still work. (On a properly functioning cooling system I think that the coolant gauge, while slower to react than a pyro, should still give you plenty of warning before you overheat with any catastrophic consequences)

[Mr. Flibble]

Forgive me if I'm wrong but doesn't a diesel engine work by compressing the air, which causes heat ,that then causes the diesel which is injected to spontaneously combust? Doesn't diesel have a higher flashpoint than gasoline?

Nope, that is correct. Diesel has a "Cetane" rating which shows how easily a given fuel will detonate. Gasoline, on the other hand, has an "Octane" rating, which is the ability to RESIST detonation (knocking). Thus, a diesel fuel will detonate when compressed with air, and gasoline will generally only ignite when the spark plug fires.

If you put Diesel fuel in a gas engine, the high Cetane rating means that the engine will knock badly (and probably not run well in either case!) And if you put gas in a diesel engine it won't detonate. (Never mind the fact that you will destroy things like your injection pump that expect to have diesel fuel as a lubricating oil!)

[loki]

Forgive me if I'm wrong but doesn't a diesel engine work by compressing the air, which causes heat ,that then causes the diesel which is injected to spontaneously combust? Doesn't diesel have a higher flashpoint than gasoline?

Nope, that is correct. Diesel has a "Cetane" rating which shows how easily a given fuel will detonate. Gasoline, on the other hand, has an "Octane" rating, which is the ability to RESIST detonation (knocking). Thus, a diesel fuel will detonate when compressed with air, and gasoline will generally only ignite when the spark plug fires.

If you put Diesel fuel in a gas engine, the high Cetane rating means that the engine will knock badly (and probably not run well in either case!) And if you put gas in a diesel engine it won't detonate. (Never mind the fact that you will destroy things like your injection pump that expect to have diesel fuel as a lubricating oil!)

I believe diesel also doesn't really detonate, it burns, this is what gives it the low end power as the piston gets pushed down for a longer period, this is also what limits the RPMs more than on gas motors where the fuel explodes expelling all it energy at the top of the stroke allowing for higher rpms. not sure if I explained that properly.

[Mr. Flibble]

I believe diesel also doesn't really detonate, it burns, this is what gives it the low end power as the piston gets pushed down for a longer period, this is also what limits the RPMs more than on gas motors where the fuel explodes expelling all it energy at the top of the stroke allowing for higher rpms. not sure if I explained that properly.

Really? I always thought a diesel detonated - akin to a gas engine's knocking. But I am only an armchair physicist! So I am prepared to be corrected on that!