patdaly

Ok Levi, you are da man.

Us silly Engineers will just sit in the corner.

I wish you well in your endeavors.

1972RedNeck

And the unlearned such as myself will sit around with our mouths hanging open.

1972RedNeck

Updates?

Rick 12v CTD

he is right in that injector pop off pressure is different than injection pressure. The VE injection pressure I'm pretty sure is actually 17000psi and the ppump is 18000. The injector is a valve like he mentioned. As the pump increases the pressure the injector won't open until 245BAR on the VE but the pump will still increase the pressure all the way up to 17000psi through the injection event. I could be wrong, but I'm pretty sure that's what happens.

The problem with raising the injection or the injector popoff pressure in a VE is it is really hard on the VE because only 1 barrel feeds all 6 injectors. I would think messing with the VE injection pressure much would cause premature failure of the pump. I know it's not recommended to go any higher than about 260BAR on the injectors and that's like what, 220psi above normal?

When a VE gets in the higher ranges of it's HP potential it becomes a battle of pressures because of the single barrel not having enough fill time which doesn't allow total injection pressure to reach it's peak which in turn causes less adequate atomization. That, I believe, is why same for same power wise a VE runs dirtier and requires more air than a ppump, especially above 400hp

Also, the ppump does make cleaner power I believe partly because of higher injection pressures of the pump which helps atomize the fuel better but the other factors that have already been pointed out as well play a fundamental role in the higher power output of the ppump

Now of course I could be wrong about all of this but I digress...

@OP. I wouldn't mess with the project. It would be a massive undertaking, and the pros won't outweight the cons (mostly time and money).

If anything I would just VE pump a 6.7 motor, which has been done and is quite the project in itself. or get a 24v motor and put a VE on that if you want to do something different.

patdaly

I am not discounting that to inject fuel, pressures must rise past the pop pressure and remain there thru the injection event. What I do call BS on is the amount of rise given.

I have no doubt that the VE is capable of statically producing 17K PSI, however that is a far cry from trying to get to that pressure in a dynamic event, given the cam travel available and say a typical 5 x .010 injector ( I am not sure what stock is )

I have looked for a honest injector pressure trace from a VE system, and I can't find it anywhere......

If anyone can post a trace, I will humbly retract my statement, after all, I am learning along with the rest of you.......

Mike L

Jeez, and the only thing that has pi!!ed me off so far was the derogatory reference to an "old man".

Mike

Rick 12v CTD

well you're welcome to believe that until proven otherwise. It is my understanding that commonrail systems go well into the 20000s for psi, that's why they are so much more efficient and why they warn so extensively about getting a trained professional to work on them.

Of course these 2 links aren't for the VE but it establishes that injection pressures get far beyond the VE injection pressures. Which, in a roundabout way legitimizes what we're saying.

Obviously you can call into question the legitimacy of wikipedia, but it is pretty common knwoledge that diesels operate at incredibly high pressures. I knew some common rail systems operate into the 30000psi range.
http://en.wikipedia.org/wiki/Common_rail
Here's another one directly from Bosch. Straight up says their commonrail pumps supply the rail (which is the injection pressure) with 1100-2200BAR
http://de.bosch-automotive.com/en/pa...motorsys_parts

patdaly

Common rail systems absolutely run in those ranges, but they do not rely on mechanical actuation of the injectors.

I'm not going to get real deep into this debate, Levi or anyone else is free to experiment, but let me leave you with this thought.

If it were as simple as wikkipedia makes it sound, why does it cost so much?

Dieselbuilder

I thing after reading all this whats your end game, expectations on that kind of expense?

j_martin

Lots of info to think on. Actual event pressure after pop would depend on delivery rate and relief through the nozzle. That explains why using smaller injectors and turning up the pump tends to run much cleaner. I ran some 7x10 injectors with approximately stock pump settings. Fun to drive, but aggravated anybody behind me big time. Oiled up and greyed out my shiny bass boat also.

Next try will be to molest the pump and leave the stock injectors in.

CoolGuyLevi

Reputable source?

http://www.dieselpowermag.com/tech/0...jection_pumps/

patdaly

Pumps are not actual pressure traces.

Pumps MUST provide more pressure capability than needed.

I have no doubt whatsoever, in a static condition, the VE will deadhead 17K.

I cannot find any pressure traces of injectors running that come anywhere near that for a mechanical injection event.

Have you ever had a VE apart?

CoolGuyLevi

yes I have, you may be right about the pressure not actually reaching those pressures. I do know one thing and that is that with pumps, pressure is relative to blockades. pumps do not create pressure on their own, they create flow. Pressure is determined by amount of flow(volume) and the restriction in this case the Injectors. I dont like this argueing thing thats going on. I do however appreciate the responses... it makes me second guess myself which is a good thing. What it all comes down to is will my pump work well when i'm done? Sometimes things seem to work better when its only on paper

patdaly

I don't like arguing either, we both know how they work.

I will make this prediction, if you try and use the VE for your purposes, you will be requiring core VE's in large quantities, specifically the cams......

If you really want to build power, just step up to common rail electronic where event timing can be precisely timed.

1972RedNeck

Correct me if I am wrong, but the poor atomization that VE's are known for is because the one barrel that has to feed all 6 cylinders can't completely refill after firing each injector when running big nozzles and higher RPM. This in turn leads to lower injection pressures.

Our injection pressures are only about 1,000 Psi less than a P Pump, correct? If yes, what is to be gained by raising pressure unless you can completely refill the barrel?

Does any of that make sense or am I off my rocker?