Does that mean that all of the injection events of your 05 occur at a time that is advanced or equal to that of the single injection event of your 92? I kinda doubt it.
Timing is really hard to compare between trucks as one is a predetermined mechanical advance curve while the other is dynamic based on a multitude of factors. At some point the timing is equal and I am running a bit more fuel thru the 92 with less EGT's.
EGR (exhaust gas recirculation) means that some portion of the exhaust of the engine is diverted to the incoming air charge entering the cylinder
Its implemented this way but why does it have to be? What is being accomplished by using EGR? In a nutshell, a portion of the incoming charge is replaced by oxygen poor air to reduce combustion temps thereby reducing NOX formation. Close enough for comparisons?
Basically, we know where the dead air comes from and we know where it has to go, so what you're talking about is apparently some invisible, mysterious and really arcane method of getting it from A to B.
Why do we have to get the dead air from point A to B? Its nothing invisible, arcane, or even mysterious. Furthermore, its the basis that has been used for since 1968 when the first emissions standards ushered in the end of the muscle car era. Hint: compare a performance cam profile to a stocker.
I guess you could close the exhaust valves early and not completely exhaust the cylinder, leaving some spent gasses in the cylinder but that would really screw up the operation of the engine, seeing as how it's basically just a big air pump in the first place
That would mean we have about 40 years worth of screwed up engines, which is not far from the truth. :-laf Your a lot closer to the truth than you know.
Closng the exhaust valve early would interfere with the overlap and we need the overlap between intake and exhaust to promote cylinder scavenging. The air flow from intake to exhaust promotes a swirl in the cylinder to scavenge it but it also tends to mix the incoming charge with the existing air. To promote performance we need to exhaust as much air as possible, good and bad, to make sure we have as much oxygenated air as possible. This is what cam profiles do with overap and valve timing.
Back to your comment, "leaving some spent gasses in the cylinder". How about delaying the opening of the exhaust valve but holding overlap and lift close to the same numbers? We still have an overlap and swirl to scavenge the cylinder, remember incoming air is mixing with the spent charge, but we start the process later and end roughly at the same time. We now have a mixed air charge with exhaust gasses in it.
Wait a minute!!! Isn't that what EGR valves and pipes and intake ducting accomplishes? Have we not accomplshed the EXACT same thing with a LOT less parts? If it walks like a duck... ..... :-laf :-laf
Excerpt from Cummins web sit:
To meet the new emission standards, Cummins applied its technology to provide an in-cylinder solution along with a diesel oxidation catalyst. Cummins developed a new piston combustion bowl and a high flow electronically-controlled wastegated turbocharger to better match boost pressure to engine needs to reduce emissions.
Hmmmm? I do believe the
faulty reasoning may not be quite so... ... errr...
FAULTY!!!!
Your correct in assuming this could possibly cause a problem with the engine as an air pump, and, it doesn't explain high EGT's etc, etc. Now, what
ONE thing that a (HINT HINT) 04. 5+ engine has that
NO other 5. 9 has that could possibly add back what we have lost in power, we have lost a little prime on the air pump, and cause the three things I previously pointed out?
