[RadarRider]

For the past 9 years, I've been in & out of the diesel world. Most of my experience has been in repairing. Since I've gotten my PSD & getting into the performance side of diesels, naturally I buy all sorts of diesel magazines, & of course: hang out @ our beloved forum. In a lot of articles I've read, I always see the term "common rail". What exactly is common rail? And what would be the "opposite" of common rail? PLEASE: forgive me in advance if this is one of those "right-in-front-of-my-face" deals. I just don't 100% know diesel smack-talkin'. Know what I mean?:dunno:

 

[GETERDID]

I just gotta ask one thing....WHO TOLD YOU DIESEL WASNT EDIBLE????

 

[vitalidle]

Commen rail is what the new diesel engines are running. Its basically a fuel rail with very high fuel pressures feeding pizo injectors vs the standard low pressure fuel pump that feeds injectors in a nutshell.

 

[RadarRider]

I just gotta ask one thing....WHO TOLD YOU DIESEL WASNT EDIBLE????

My girlfriend...I tried making diesel freeze-pops, but she said they were stinking up the fridge...& threw them away!:rofl::hehe:

 

[RadarRider]

Commen rail is what the new diesel engines are running. Its basically a fuel rail with very high fuel pressures feeding pizo injectors vs the standard low pressure fuel pump that feeds injectors in a nutshell.

Are we common rails?:dunno:

 

[vitalidle]

No we are heui or hydraulic electronic unit injector with a low pressure fuel pump. Common rail injectors are strickly electronic controlled while are injectors are mechanical and electrical or hydraulically actuated with a high pressure oil system

 

[Doakster]

The main advantage of Pizoelectric injectors is that you can control the time of injection, duration of injection and the number of injections on the powerstroke very well. Some systems can inject fuel up to 4-5 times during the powerstroke. Also the other advantage is that with the high pressure of the fuel directly supplied to the injector this helps in better atomization of fuel. Common rail systems have been around for awhile now in commercial engines (cat has used them for some time now) but in the last few years they have come around in automotive diesels, alot of this is pushed by emissions. A common rail system is more or less the same as a fuel injected gas engine, they work on the same principle.

To mess with your mind a little, large commercial diesels in the 5, 10, 50, 100 thousand horse power range often use what is call a "common rail" or a "fuel rail" that is in fact low pressure. This line is a common header that supplies fuel to individual fuel pumps, these individual fuel pumps supply high pressure fuel (usually timed by the cam pushing on a plunger/piston in the pump) to the injectors. Large diesels can have sometimes up to 3 or 4 injectors per cylinder. And yes there are diesels that make more than 100,000hp you'll only find these is large merchant ships. Most people don't know diesels like that exist and they function much simpler than our truck engines. I've done a couple turbo rebuilds on 8000hp diesels, it's fun working on a turbo that is as big as a F-350 CC long bed.

 

[ABOBB]

I wonder if I can muddy the waters here just a little.

Before electronics, fuel was injected into diesel engines through the use of a pump that served multiple functions. It would pressurize the fuel, meter the amount of fuel, and control distribution timing. These pumps had individual fuel lines that lead from the pump to each injector.

Later other methods came into use. The heui system (like on a 7.3 or 6.0 powerstroke) uses common supply channels, but the injectors themselves pressurize, meter, and control distribution timing.

Common rail injections systems, as they apply to diesel trucks are more correctly termed High Pressure Common Rail. They use a supply pump that provides pressurized fuel to the injectors. The injectors then multiply that pressure, meter the fuel, and control distribution timing.

 

[RadarRider]

With all of your answers, it just proves once again that you really do learn something(or quite a few somethings!)everyday! Thanks, guys:icon_ford::thumb:!

 

[RadarRider]

The main advantage of Pizoelectric injectors is that you can control the time of injection, duration of injection and the number of injections on the powerstroke very well. Some systems can inject fuel up to 4-5 times during the powerstroke. Also the other advantage is that with the high pressure of the fuel directly supplied to the injector this helps in better atomization of fuel. Common rail systems have been around for awhile now in commercial engines (cat has used them for some time now) but in the last few years they have come around in automotive diesels, alot of this is pushed by emissions. A common rail system is more or less the same as a fuel injected gas engine, they work on the same principle.

To mess with your mind a little, large commercial diesels in the 5, 10, 50, 100 thousand horse power range often use what is call a "common rail" or a "fuel rail" that is in fact low pressure. This line is a common header that supplies fuel to individual fuel pumps, these individual fuel pumps supply high pressure fuel (usually timed by the cam pushing on a plunger/piston in the pump) to the injectors. Large diesels can have sometimes up to 3 or 4 injectors per cylinder. And yes there are diesels that make more than 100,000hp you'll only find these is large merchant ships. Most people don't know diesels like that exist and they function much simpler than our truck engines. I've done a couple turbo rebuilds on 8000hp diesels, it's fun working on a turbo that is as big as a F-350 CC long bed.

I used to work for a construction company that used Mitsubishi, Isuzu, Cat, & Duetz diesels with very similar horsepower claims like the ones you described. They were used to power generators for tower cranes. They were mounted inside a connex box and were started by a delay-controlled module located in the back of the connex box near the side of the motor where the accessory drive for the engine is. They were so loud, that when you started them, you had to run faster than the delay & make it out of the doors before the engine started. Otherwise, you'd have your ears ringing for a better portion of the day! The throttle of the engines were controlled by the electrical demand of the tower crane. If you needed to use a high-speed function of any kind, the further you'd push or pull a joystick would determine the amount of throttle the electrical system. The electrical system would send a signal to a junction box which in turn would increase or decrease engine throttle. Anyway, before I lose the point I was trying to make...these engines would put out anywhere from 5000 to 10,000hp. And most of these engines ran day & night! These engines were my 1st taste of diesel power, & boy do I miss them!

 

[Doakster]

I used to work for a construction company that used Mitsubishi, Isuzu, Cat, & Duetz diesels with very similar horsepower claims like the ones you described. They were used to power generators for tower cranes. They were mounted inside a connex box and were started by a delay-controlled module located in the back of the connex box near the side of the motor where the accessory drive for the engine is. They were so loud, that when you started them, you had to run faster than the delay & make it out of the doors before the engine started. Otherwise, you'd have your ears ringing for a better portion of the day! The throttle of the engines were controlled by the electrical demand of the tower crane. If you needed to use a high-speed function of any kind, the further you'd push or pull a joystick would determine the amount of throttle the electrical system. The electrical system would send a signal to a junction box which in turn would increase or decrease engine throttle. Anyway, before I lose the point I was trying to make...these engines would put out anywhere from 5000 to 10,000hp. And most of these engines ran day & night! These engines were my 1st taste of diesel power, & boy do I miss them!

Sounds like fun! I'm guessing these motors were direct air injection start correct? meaning that air is directly timed/injected into the cylinders to get it moving, that's what I would think all the start up noise would come from. Try looking up Sulzer Diesel or MAN B&W these are the two companies that make the big boys, in the 100000hp plus ranged. Also Hyundai Heavy industries makes them, IIRC. We're talking about diesels that are as large as a 4-5 story house, run at about 90 RPM max and there rotation can be completely reversed with air (mainly for ship board application). In addition to a connecting rod that is 10 feet tall, there will be another shaft that connects the connecting rod to the piston and only runs vertical with each piston stoke, this is due to the throw on the crank being go large and it helps reduce the overall engine size, pretty crazy stuff. I used to work as a ship board engineer in my previous life.

 

[pete37922]

as far as i remember...CAT wuz HUEI system !!!

 

[cchase]

I know what you guys mean when you talk about ships engines. I am lucky enough to have an uncle as a captain of a lake frighter. and because of this i get to ride/play on them all the time and also have won a few contracts to lift things like shafts and what not on too them, one of the cylinders on the diesel was probably as big as the bed of my truck... its insane. complety insane

 

[Safir]

To mess with your mind a little, large commercial diesels in the 5, 10, 50, 100 thousand horse power range often use what is call a "common rail" or a "fuel rail" that is in fact low pressure. This line is a common header that supplies fuel to individual fuel pumps, these individual fuel pumps supply high pressure fuel (usually timed by the cam pushing on a plunger/piston in the pump) to the injectors. Large diesels can have sometimes up to 3 or 4 injectors per cylinder. And yes there are diesels that make more than 100,000hp you'll only find these is large merchant ships. Most people don't know diesels like that exist and they function much simpler than our truck engines. I've done a couple turbo rebuilds on 8000hp diesels, it's fun working on a turbo that is as big as a F-350 CC long bed.

eye candy -
The Most Powerful Diesel Engine in the World

 

[DieselFord]

eye candy -
The Most Powerful Diesel Engine in the World

Now thats a motor.

 

[DKR]

eye candy -
The Most Powerful Diesel Engine in the World

Cool page, thanks!:thumb:

 

[Doakster]

eye candy -
The Most Powerful Diesel Engine in the World

Notice the piston shaft that I was talking about. The lower end of the piston rod is connected to the connecting rod. There is some serious rotating mass on big diesels like this, that why they only run around 100 rpm max, also they can only run around 100 rpm because these motors are usually connected directly to a prop through a line shaft, and a prop that would go with this motor would actually be about 30ft in diameter or bigger. There are no clutches either, what clutch would hold up to 100,000hp and millions of FT-lbs of torque? But think about it at 100 rpm that piston is still completing one stroke at a little less than 1.5 times per second. Also these are all 2 stroke diesels, no intake valves, just a lot of big exhaust valves, air enters the cylinder from the turbo through side ports machined in the cylinders at specific locations, usually they are fully uncovered completely at bottom dead center.