diesel engines and turbochargers

[Howard]

Originally posted by: infestedgh0st

Originally posted by: Howard

Originally posted by: ElFenix
aren't gas engines moving to direct injection?

In countries whose gas has low sulfur content, mostly.

in general, engines are moving towards direct sefi

sefi?

Actually, the main problem is the sulfur level in U.S. fuel. Both Mitsubishi and Toyota have been selling vehicles with GDI engines in the Japanese market for years. They can't sell them here because the higher sulfur levels in U.S. fuels would cause the special catalytic converters these engines use to deteriorate too rapidly.

http://www.thecarconnection.com/Auto_Ne..._Talk_Direct_Injection.S198.A4649.html

 

[natto fire]

In general though, direct injection is not a big leap foreward as port injection was over throttle body injection, or (especially) TBI was over carbueration. It is still a benefit, but port injection is still really good, especially if the manufacturer pays very close attention to the ports themselves, like in the Integra Type R. A very good breathing motor because all heads get a port job before they are installed in the car. This leads to less fuel waste and a little bump in power.

 

[geno]

Originally posted by: mercanucaribe

Originally posted by: FrustratedUser

Originally posted by: Demon-Xanth
Diesels work by using compression to fire the cylinders. Normally, in a gas engine a 25PSI turbo system would cause massive detonation. But with a diesel, it's no problem. It NEEDS a much higher compression just to fire. The turbo setup for a diesel allows it to effectively be a 6L engine at idle, and a 16L engine under load. It helps alot for gas milage. (good) Diesel engines are typically overbuilt because of thier long use applications, so they handle the extra stress well.

A turbo or super charger DOES NOT CHANGE THE COMPRESSION RATIO!

You're putting more air in the same volume, of course it's changing the compression ratio. Just because your head can only comprehend the ratio of the cylinder's volume at the bottom of the stroke compared to the top, doesn't mean that the compression ratio of the air itself isn't changing.

wrong wrong wrong, it doesn't matter if you're forcing 25psi into a cylinder or 5psi, it's all being compressed at the same ratio. What forced induction does increase is cylinder pressure, but not the ratio.

 

[Sundog]

.


http://www.dragonsys.org/files/videos/F350Run.wmv<-----Watch the movie.

 

[arcenite]

Originally posted by: Sundog
.


http://www.dragonsys.org/files/videos/F350Run.wmv<-----Watch the movie.

I am going to build one of these someday.

 

[Zenmervolt]

Originally posted by: Captain Howdy Even with a turbo, diesels still have really low redlines due to the inherit nature in the way they combust fuel.

So, so, so, so wrong....

Diesels are typically low-revving engines because they are generally built with long strokes that increase mean piston velocity and out of very heavy-duty componants that risk being out of control at higher RPM. A heavy piston and connecting rod simply cannot be effectively controlled at high RPM, and the piston and rod _have_ to be heavy in order to cope with an 18:1 compression ratio and 20+ PSI of boost pressure. The rev limits on diesel engines have _nothing_ to do with the ignition source for their fuel.

ZV

EDIT: The 3.2 litre CDI engine in Mercedes E320 diesel has a 5,000 RPM redline. It's not astronomically high, but it's hardly lower than the redline for some older American V8s.

 

[cavemanmoron]

more power.

simple.

 

[mercanucaribe]

Originally posted by: geno

Originally posted by: mercanucaribe

Originally posted by: FrustratedUser

Originally posted by: Demon-Xanth
Diesels work by using compression to fire the cylinders. Normally, in a gas engine a 25PSI turbo system would cause massive detonation. But with a diesel, it's no problem. It NEEDS a much higher compression just to fire. The turbo setup for a diesel allows it to effectively be a 6L engine at idle, and a 16L engine under load. It helps alot for gas milage. (good) Diesel engines are typically overbuilt because of thier long use applications, so they handle the extra stress well.

A turbo or super charger DOES NOT CHANGE THE COMPRESSION RATIO!

You're putting more air in the same volume, of course it's changing the compression ratio. Just because your head can only comprehend the ratio of the cylinder's volume at the bottom of the stroke compared to the top, doesn't mean that the compression ratio of the air itself isn't changing.

wrong wrong wrong, it doesn't matter if you're forcing 25psi into a cylinder or 5psi, it's all being compressed at the same ratio. What forced induction does increase is cylinder pressure, but not the ratio.

The compression ratio of the cylinder doesn't change, but the compression ratio of the engine does. I define that as the ratio between the volume of air taken in by the air intake to the volume it is compressed to by a stroke.

Do jet engines have 0 compression?

 

[TomKazansky]

Originally posted by: mercanucaribe

Originally posted by: geno

Originally posted by: mercanucaribe

Originally posted by: FrustratedUser

Originally posted by: Demon-Xanth
Diesels work by using compression to fire the cylinders. Normally, in a gas engine a 25PSI turbo system would cause massive detonation. But with a diesel, it's no problem. It NEEDS a much higher compression just to fire. The turbo setup for a diesel allows it to effectively be a 6L engine at idle, and a 16L engine under load. It helps alot for gas milage. (good) Diesel engines are typically overbuilt because of thier long use applications, so they handle the extra stress well.

A turbo or super charger DOES NOT CHANGE THE COMPRESSION RATIO!

You're putting more air in the same volume, of course it's changing the compression ratio. Just because your head can only comprehend the ratio of the cylinder's volume at the bottom of the stroke compared to the top, doesn't mean that the compression ratio of the air itself isn't changing.

wrong wrong wrong, it doesn't matter if you're forcing 25psi into a cylinder or 5psi, it's all being compressed at the same ratio. What forced induction does increase is cylinder pressure, but not the ratio.

The compression ratio of the cylinder doesn't change, but the compression ratio of the engine does. I define that as the ratio between the volume of air taken in by the air intake to the volume it is compressed to by a stroke.

Do jet engines have 0 compression?

you're tryign to say that after forced induction, the pressure within the cylinder wall increases as the engine strokes, but the compression ratio the piston ring provides stays the same. Use this explanation from now on before you confuse anyone else. He is on the right track but has been using the wrong termenology to explain it.

Originally posted by: Howard
sefi?

sequential electronic fuel injection. vvti/vvtli/i-vtec all have sefi, I THINK.

 

[Howard]

Originally posted by: mercanucaribe

Originally posted by: geno

Originally posted by: mercanucaribe

Originally posted by: FrustratedUser

Originally posted by: Demon-Xanth
Diesels work by using compression to fire the cylinders. Normally, in a gas engine a 25PSI turbo system would cause massive detonation. But with a diesel, it's no problem. It NEEDS a much higher compression just to fire. The turbo setup for a diesel allows it to effectively be a 6L engine at idle, and a 16L engine under load. It helps alot for gas milage. (good) Diesel engines are typically overbuilt because of thier long use applications, so they handle the extra stress well.

A turbo or super charger DOES NOT CHANGE THE COMPRESSION RATIO!

You're putting more air in the same volume, of course it's changing the compression ratio. Just because your head can only comprehend the ratio of the cylinder's volume at the bottom of the stroke compared to the top, doesn't mean that the compression ratio of the air itself isn't changing.

wrong wrong wrong, it doesn't matter if you're forcing 25psi into a cylinder or 5psi, it's all being compressed at the same ratio. What forced induction does increase is cylinder pressure, but not the ratio.

The compression ratio of the cylinder doesn't change, but the compression ratio of the engine does. I define that as the ratio between the volume of air taken in by the air intake to the volume it is compressed to by a stroke.

How does the volume increase when the air is compressed to higher-than-ambient pressure?

 

[Howard]

Originally posted by: infestedgh0st

Originally posted by: mercanucaribe

Originally posted by: geno

Originally posted by: mercanucaribe

Originally posted by: FrustratedUser

Originally posted by: Demon-Xanth
Diesels work by using compression to fire the cylinders. Normally, in a gas engine a 25PSI turbo system would cause massive detonation. But with a diesel, it's no problem. It NEEDS a much higher compression just to fire. The turbo setup for a diesel allows it to effectively be a 6L engine at idle, and a 16L engine under load. It helps alot for gas milage. (good) Diesel engines are typically overbuilt because of thier long use applications, so they handle the extra stress well.

A turbo or super charger DOES NOT CHANGE THE COMPRESSION RATIO!

You're putting more air in the same volume, of course it's changing the compression ratio. Just because your head can only comprehend the ratio of the cylinder's volume at the bottom of the stroke compared to the top, doesn't mean that the compression ratio of the air itself isn't changing.

wrong wrong wrong, it doesn't matter if you're forcing 25psi into a cylinder or 5psi, it's all being compressed at the same ratio. What forced induction does increase is cylinder pressure, but not the ratio.

The compression ratio of the cylinder doesn't change, but the compression ratio of the engine does. I define that as the ratio between the volume of air taken in by the air intake to the volume it is compressed to by a stroke.

Do jet engines have 0 compression?

you're tryign to say that after forced induction, the pressure within the cylinder wall increases as the engine strokes, but the compression ratio the piston ring provides stays the same. Use this explanation from now on before you confuse anyone else. He is on the right track but has been using the wrong termenology to explain it.

Originally posted by: Howard
sefi?

sequential electronic fuel injection. vvti/vvtli/i-vtec all have sefi, I THINK.

Sequential multi-port injection is used on a lot of engines, I think, not just the ones with variable valve timing/lift.

 

[Captante]

All the complex explanations of how turbo-diesels work is very interesting, but the simple answer to the op's question is to improve overall power & drivability, for trucks the most important area of improvment is better performance at increased altitude, as in when climbing over the Rocky mountains & in cars faster & more even acceleration.

 

[TomKazansky]

Originally posted by: Captante
All the complex explanations of how turbo-diesels work is very interesting, but the simple answer to the op's question is to improve overall power & drivability, for trucks the most important area of improvment is better performance at increased altitude, as in when climbing over the Rocky mountains & in cars faster & more even acceleration.

forced induction decreases drivability. it just increases the engine's output of power.

 

[d33pt]

why do semi truck drivers idle their engines all night long while sleeping?

 

[funboy6942]

They actually use less fuel running all night then it would to shut them down and restart the engine cold.

 

[c3p0]

Originally posted by: funboy42
They actually use less fuel running all night then it would to shut them down and restart the engine cold.

Now I find that really hard to believe.

c3p0
:beer:

 

[thedarkwolf]

Originally posted by: c3p0

Originally posted by: funboy42
They actually use less fuel running all night then it would to shut them down and restart the engine cold.

Now I find that really hard to believe.

c3p0
:beer:

Diesel engines take forever to warm up and don't start well in the cold so if its cold out they will leave them running sometimes depending on how cold and how long they plan to stop. And diesels do use very little fuel while ideling.

 

[Demon-Xanth]

It only costs the truckers $5 in gas to idle all night, which lets them stay warm, power accessories, and the engine is ready to go when they get up. I've heard of places in Alaska where people will leave thier engines running in the parking lot while they work because the cost of gas outdoes the problems of freezing any day.

 

[paulney]

While on the topic of diesels: the new european diesels claim to be a lot more eco-friendly in terms of lower emission and even lower fuel consumption. But diesel fuel in Europe is low on sulfur, while the one we have in US - you could probably extract sulfur and sell it in bricks. How do these engines perform here? Like the new VW Jettas for example?

 

[funboy6942]

Originally posted by: thedarkwolf

Originally posted by: c3p0

Originally posted by: funboy42
They actually use less fuel running all night then it would to shut them down and restart the engine cold.

Now I find that really hard to believe.

c3p0
:beer:

Diesel engines take forever to warm up and don't start well in the cold so if its cold out they will leave them running sometimes depending on how cold and how long they plan to stop. And diesels do use very little fuel while ideling.

I know when I was driving I always left mine running cold/hot didnt matter. Not only do you save fuel durring start up while the engine comes to temp but less wear on the engine as well from not starting shutting off all the time. Everything stays at temp and and lubricated ready to go once you wake up and fill out the log.
A truck in winter when trying to start will use up gobs of fuel for sure. You should see one start in the dead of winter. Blows out a mixture of black and blue smoke (black excessive fuel and blue is oil getting past the piston and rings) for a good 10 minutes till reaches opt temp. A diesel engine takes forever to warm up.

EDIT

Looks like the gov is stepping in and putting an end to engine idling.
Claiming it is using too much fuel and damaging the inviroment. Funny thing is they will get the support of the us for this because of eco concerning nuts. But they are basing it is causing more damage to an engine (bs cold starts will), and thier killer defense along with eco concerns is sooner oil changes. OBVIOUSLY they only did the study on the engine and what it spits out the exhaust at idle over night. Hate to think how much more pollutants are thrown into the air from having to start a cold truck (see above what a diesel does cold). I can bet anything it is tripple the ammount at cold start then to let it run all night. Did the asshats do a study on that? NO!

Lets shut the engines to save "fuel and the air" but not do a study on how much crap goes into the air and fuel is wasted at cold starting :/

 

[newParadigm]

i lost my understanding in this thread like 8 posts up

 

[TomKazansky]

cold startup FTL

 

[TomKazansky]

cold startup FTL

 

[cavemanmoron]

Originally posted by: funboy42

Originally posted by: thedarkwolf

Originally posted by: c3p0

Originally posted by: funboy42
They actually use less fuel running all night then it would to shut them down and restart the engine cold.

Now I find that really hard to believe.

c3p0
:beer:

Diesel engines take forever to warm up and don't start well in the cold so if its cold out they will leave them running sometimes depending on how cold and how long they plan to stop. And diesels do use very little fuel while ideling.

I know when I was driving I always left mine running cold/hot didnt matter. Not only do you save fuel durring start up while the engine comes to temp but less wear on the engine as well from not starting shutting off all the time. Everything stays at temp and and lubricated ready to go once you wake up and fill out the log.
A truck in winter when trying to start will use up gobs of fuel for sure. You should see one start in the dead of winter. Blows out a mixture of black and blue smoke (black excessive fuel and blue is oil getting past the piston and rings) for a good 10 minutes till reaches opt temp. A diesel engine takes forever to warm up.

EDIT

Looks like the gov is stepping in and putting an end to engine idling.
Claiming it is using too much fuel and damaging the inviroment. Funny thing is they will get the support of the us for this because of eco concerning nuts. But they are basing it is causing more damage to an engine (bs cold starts will), and thier killer defense along with eco concerns is sooner oil changes. OBVIOUSLY they only did the study on the engine and what it spits out the exhaust at idle over night. Hate to think how much more pollutants are thrown into the air from having to start a cold truck (see above what a diesel does cold). I can bet anything it is tripple the ammount at cold start then to let it run all night. Did the asshats do a study on that? NO!

Lets shut the engines to save "fuel and the air" but not do a study on how much crap goes into the air and fuel is wasted at cold starting :/

If you live anyplace near where the trucks were idling for the night,the sound and the exhaust smell is much worse,from 30 trucks idling for 4-8 hours,than from them starting up,running for 3-10 mins and then driving away.

I used to live less than a mile from where this occured,and if the wind was blowing the
fumes towards my house,I could not leave my windows open in my home.

Where I work I drive dump trucks,diesel loaders,etc.and Yes in the winter they smoke,
when first started.