maybe dumb

6.4s have common rail injection, i think, so i hope this belongs here.
What is so great about common rail injection? Why does it make such a big differance?
yes this may be the dumbest question asked, but i am still new to diesel.
thank ya

its more efficient and has other advantages.

super high pressures 24,000 fuel pressure at the rail
At that pressure you gain tons of advatages, super precise control over timing, fuel delivery, better fuel atomization, amount of fuel and when that fuel is deliverd ect. ect

and the injectors dont run off oil pressure like the 7.3 and 6.0 do so you can push more fuel to them alot easier

An injetor can hang open and destroy an engine too. Just had it happen. LOL now, but It hurt real bad when it happened. Still workin on fixin that wreck

but that was a cummins wasnt it haha

lol Right as I under stand the New 6.4 PowerStroke is the high pressure common rail fuel injection system with piezo-electric injectors. The high pressure oil pump has been replaced by a high pressure (up to 26,000 PSI) fuel pump driven off the camshaft at the rear of the engine. The piezo discs in the actuator flex and press on a hydraulic check valve, which causes fuel pressure in the control chamber to bleed off. Fuel pressure in the high pressure chamber causes the nozzle needle to lift off its seat and fuel passes through the spray holes at the nozzle tip. The ECM deactivates the injector by reversing polarity to the piezo discs. This allows spring pressure to close the check valve, fuel pressure builds in the control chanber, and the nozzle needle closes, ending injection. So what happens if the Actuator sticks. Kaboom

haha thank you for painting the picture of that catostrophic engine failure for me, you should be a novelist con'twinforlosing :)

Right It may not be the biggest tool in the tool box but it gets it own drawer. "7.3 PowerStroke can't be beat with a stick"

What i dont understand is if the engine starts to run away on a hung up injector, you think simply cutting the key off would shut it down, but it must not command the pump to basicly shut down, it just must shut the PW down, and when the injector is stuck that can't happen, Ill take a 6.4 over a 7.3 anyday, been a GREAT truck this far.

the problem is it will overfuel enough to melt a piston before you notice anything.

the problem is it will overfuel enough to melt a piston before you notice anything.

i understand that, just saying in a full run away situation.

When you shut the key off, it kills the fuel pump, injector pulse width, and the HPFP. If you still have a runaway, it's not diesel it's running on, and you have bigger issues.

When you shut the key off, it kills the fuel pump, injector pulse width, and the HPFP. If you still have a runaway, it's not diesel it's running on, and you have bigger issues.

Thats always the way that i have understood it, most of the time and when they do run away like that is usually off engine oil from the turbo's, BUT i have heard of two engines that have gone down (runaways) and FORD both times has said it was injectors :shrug:

When you shut the key off, it kills the fuel pump, injector pulse width, and the HPFP. If you still have a runaway, it's not diesel it's running on, and you have bigger issues.

they will run on engine oil so... you are very correct!!!!

they will run on engine oil so... you are very correct!!!!

I've heard of older trucks sucking oil past the valve guides running on, never seen it in person.

As to the orginal post, 1 ?- If the 6.4 is so much better (I'm not decenting) why kill it so soon, or is the scorpion just the 5hit and a side of chips.

I've heard of older trucks sucking oil past the valve guides running on, never seen it in person.

As to the orginal post, 1 ?- If the 6.4 is so much better (I'm not decenting) why kill it so soon, or is the scorpion just the 5hit and a side of chips.

Its simple, ford is breaking ties to international, thats all it comes down to, Ford produced engine, no relying on an outsource to meet the specs you desire.

Its simple, ford is breaking ties to international, thats all it comes down to, Ford produced engine, no relying on an outsource to meet the specs you desire.

I guess I should have been reading the 6.7 posts. I just assumed they were still together. :doh:

I was running the valve rack on the Cummins and before I could get to the Key, it was all over but the crying. The injector filled the cylinder so fast that it bent a rod and curled the connecting rod bearing in #4 hole.

Filling the cylinder and bending rods is not the same as a runaway. A runaway is just that, it keeps running no matter what you do.

well that would be bad luck with a combination of karma. run this past me again, it keeps going after the fuel is shut off because the oil is being combusted instead?

well that would be bad luck with a combination of karma. run this past me again, it keeps going after the fuel is shut off because the oil is being combusted instead?

It can be, i suppose if an injector hung open long enough to fill the crank case full of fuel, to the point where it was over full and was pushing passed the rings and running on the fuel/oil mixture enough to run on that... not sure.

Okay Not Sure How that happened. But we weren't talking about runaways. The comparison I made was the Huei to the Common rail. The common rail injection system is more precise. However the common rail is capable of causing catastrophic engine damage in the blink of an eye. There is no intermediary buffer except for a small soft check valve and electrical parts. The cummins common rail injectors have a small hockey puck, under spring load that holds an equalization chamber at a higher mechanical advantage than the pinnel valve. When this puck is lifted from its seat, an equalization of pressure begins, and allows fuel pressure (appx 20,000 psi) to lift the lower injection pinnel off of its seat. There is a check valve in the upper equalization chamber that is supposed to restrain this differential. This check becomes worn and will fail to check. With out restraint the fuel can be unlimited. I took one of the morose mothers apart. After seeing the internal parts no wonder they fail.
Look at the end of a ball point pen. The ball in the end of the pen is comparable to the diameter of this check valve. The puck disc is twice the diameter of #2 pencil lead. Perhaps some high fuel flow governing device could be engineered to restrain each individual injector from this over fuel situation.. In comparison the Huei injection system max fuel is limited, a draw back none the less.

The 2 stroke Detroit's were notorious for this crankcase oil for fuel situation . They had an air supply butterfly to kill the engine, but I saw a guy stall a truck by hanging it on some structural steel. The drive train loaded up and when the engine quit pulling in a forward direction, the drive train stored energy started the engine in reverse. (These engines have cam operated injectors) The operator was confused. He turned off the ignition, but it was too late. It no longer needed an air supply or fuel supply. It began to suck engine oil from the exhaust side of the turbo seals the more oil it pulled the more air it got through the crank case ventilation, and away we go. It was the loudest thing I have ever heard. The thing was like a grenade.

well i have another dumb question, why do people use delete in front of mods names? Like soup bowl delete for an idi, or an exhaust delete? i would like to know what they are talking about there.

Most poeple dont consider thoughs mods on this site, on others you will find alot of lingo like that but most people just state they have an exhaust intake ect ect.

i was just wondering if it was some sort of hint at something, or i have no idea i was just confuesd as to how you would delete an exhaust

Bend a valve.

ANother common rail advantage is at super cold temps you aren't relying on oil to actuate your injectors... eliminating rough cold starts (for the most part)

well that is good too know thank you

The reason why common rail injection is superior to HEUI is Injection Pressure. The HEUI can't produce the amount of IP the CR can put out. CR injection pressure is around 20K~26K, HEUI I have read before was somewhere around 13K. The more injection pressure you have, the more power you will make.

ok that little tid bit was helpfull