dieselfreak21

Need some help please. I need some new injector lines. Figured if going to the trouble I would bend a custom set for another plan I have. I need to find a supplier of straigh injector lines the same length with the correct ends for a VP44 24v Truck. I need to know what bending tools is used that bends the lines while maintaining the structural integrity.

And if anyone has any opinions on .093 size line and tubes with a SO VP fueling 200 hp injectors. Steetablity is of no concern. Would even like the lope i hear is rumored with them.

Thanks for any help.

Tate

Schied's carries the straight lines. Pure Diesel Power can get them too. Might want to ask them about bending tools, but I think a typical tubing bender would be ok.

Any particular reason for the bigger lines with and SO pump?

HOHN

Buy stock.

Justin

Or if it helps you take more more seriously:

Justin Hohn
HP Fuel Line Development Engineer
2010 ISX15/ISX11.9
Cummins Engine Company.

dieselfreak21

Tate will check those to places out. Thanks. Plan on running bigger injectors and figured I would leave a little extra capcity but i could be wrong it could mess with time and atomization to much to get any benifit. Plus hear it gives you some lope which would just raises the cool factor for me personally.

HOHN are you meaning line size or just stock line replacements? Need to make up for some of the intakes design flaws for performance applications.

HOHN

I can't advise you on line SIZE per se-- you're off the reservation, so to speak, and you'll have to work out line size yourself.

But I will tell you this:

There are two manufacturers of common rail fuel tubing in the world. The process of manufacturing the tubing is very demanding and leaves little to no margin for error. This isn't parts store tubing folks. So, forget "custom" common rail fuel tubes.

On a VP truck, you might or might not get away with different tubes. It's still very highly spec'd tubing that has significant development effort ensuring it will survive.

That system of fuel line clamps is there for a reason-- testing showed that an unclamped line would eventually fatigue itself and fail due to vibration.

I'm not sure what amateur testing was done to demonstrate that need for larger fuel lines but I'd think it unlikely that HP fuel tubes where the big obstacle to more horsepower.


So, the bottom line is that it's just an unfavorable cost/benefit. ON the benefit side you have lopey idle and MAYBE a couple horses (MAYBE). ON the cost side you have money and reliability.

To me it's obvious that you look elsewhere for horsepower...

JMO

Mike Holmen

Hohn, how does the factory bend the tubes? Are they stress relieved on the bends.

I done the fatigue testing, the lines rub on each other, causing the lines to cut thru each other. I was injector testing and I broke a few injector line hold down clamps.

Good info guys, keep it coming.

dieselfreak21

My common rail truck will stay with the factory stuff. To much PSI to be messing with and the computer controls make tunning limitless. I'm not any expert by any means so I appreciate all your input Hohn. What is the opperating pressures on the VP is any one knows. I know I want better air flow to the head not really for hp gains just would like to see even EGT across all cyclinders. If i benth them I planned on clamping them but unless mine have fallen off the clamps are just the the 1st set of bends. Should there be other glamps on the groups of injector line if they are close?

Mike Holmen

Best way to balance out flow into each cylinder, you hack off the intake. #1 and #6 have real limits to how much air flow can go into the cylinder. Typically a head doesn't to flow well past 0.5in lifts on the valve. I'm getting a head ready for some big flows. We will see if you can get anymore power from doing this. I'll post the flow numbers once they become available.

Tate

Peak pressures are around 16.5 ksi if I remember right.

HOHN

I can only really speak of the parts I've worked on for the new ISX, but I'd imagine the VP lines are similar.

Speculating on the VP lines:

The tubing is seamless, usually extruded, CNC hydrobent (hydraulically pressurized while bending), then autofrettaged. That's the process where you hydraulically "shot peen" the ID with short bursts of super high pressure fluid.


I want to say the 16.5Ksi number is about right for VP operating pressures.

The XPI system on the engine I work on is substantially higher pressure than even the Bosch rail system. Bosch is 1800bar; XPI is over 2500bar and climbing. It's the highest pressure CR system used in a heavy duty engine--anywhere.

JH

dieselfreak21

Well that explains the price of lines as well. I never thought it was just regular tubing but wow they put some work in them. great info.

Mike I need your deep pockets for the right way to do the head work. The intakes and the machining cost some major bucks. hope if give a HP gain at that point. if there is a way to get before and after flows that would be great.

Mike Holmen

Yes, I will be getting flow number before and after. I need to get a custom cam grind to match the what else I'm doing to the engine.

Its not as pricey as you think or as difficult to cut off the intake. I will have to see about getting pictures along the way. We are going with a custom build intake. I'm still working on the drawings at this point. No doubt, its going to be a neat truck, once everything goes together.

13FOX

HOHN you have a pm.

Mastsuura

Who bends these lines, or who manufactures the machines to do such? I have been looking around but no one I've talked to so far bends the 8mm od 3mm id lines.