delivery valve

N

nilsson

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Sep 28, 2009
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Whats the main task for the dv`s? To be non- return valve? Way is it so much different sizes, is it not just to regulate fuel with the injectors. Or the opposite, not so many injector sizes and just regulate with the delivery valve. Wich is the opening pressure of a delivery valve?
Hope some can explain little for me.
Regards
 
dv's regulate the amount of fuel sent through the lines to the injectors dv's that are cut more such as laser cut's ect. and the different sizes allow more fuel to pass through in the amount of time the dv is open.

DV's don't open on pressure they ride on a cam think of them like a piston or lifter on a car. Basically the P pump is like a mini motor in its self the outer holder of the dv is the cylinder sleeve and the dv is the piston and the cam in the pump is well a cam or like the rod ect. in a normal motor.

On the other hand fuel injector though do open on pressure and then squirt fuel in to the cylinder and the bigger the holes in the tip the more fuel but you need big enough dv's to allow enough fuel into the lines to keep the injectors feed fully at all times.

Hope that helps some maybe not the greatest explanation in the world but that is the general theory of it all.
 
"In the course of the delivery stroke, the increasing pressure in the plunger chamber lifts the delivery-valve cone from the valve seat in the delivery-valve body. Fuel then passes through the delivery-valve holder and into the high pressure delivery line to the nozzle."

1201091344.jpg
 
my Bosch book (ISBN-3-934584-68-3) apparently the same one that Bryce has said:
The delivery valve is fitted between the plunger-and-barrel assembly and the high pressure delivery line. Its purpose is to isolate the high pressure delivery line from the plunger-and-barrel assembly. It also reduces the pressure in the high-pressure delivery line and nozzle chamber following fuel injection to set static pressure. Pressure reduction causes rapid and precise closure of the nozzle and prevents undesirable fuel dribble into the combustion chamber.
Click to expand...


Basically the valve has two purposes: 1) to isolate the plunger and barrel from the fuel line and 2)to put a clean end to the fuel delivery.
The valves are opened based on the pressure in the plunger cavity and closed by the force of the spring above the delivery valve.

They are not used to meter the fuel volume injected, that's what the helix(s) in the plunger are used for. And they are certainly not opened and closed by a camshaft. The plungers ride on a cam which I hope is what KingS was thinking of.


The shoulder is what retracts the fuel from the injection line. Changing the shoulder length has a direct effect on how much fuel is removed from the line and how far the valve needs to travel before fuel can flow around it.
In the case of laser or full cuts there is no shoulder to retract fuel on the delivery valve is often unable to do its job effectively. Because of this laser cuts often have poor end of injection characteristics and allow fuel to dribble into the cylinder long after the injection event should have taken place. This process leads to the smoke and heat associated with laser cuts.

Changing the other characteristics of the valves changes how well the fuel will flow around the valve and help to provide a smooth flow of fuel to the injector.
 
ok I guess was wrong on the pressure part.

I was under the impression that the cam lope lifted the dv up and down and the spring maintained tension on the top of the dv so that it follow the lobe shape of the cam. My bad there; I'm no professional I just tore my stuff off and looked observed ect. an thought that is the way mine was working. As for laser cut's I never seen one's with out a shoulder left on them interesting to know. My dv's I had made flowed more then laser cuts and still had shoulder left on them and sealed lick they should on there cycles. So new info to remember. And the dv's do control how much fuel is allowed to enter the fuel injections lines that is why we change the dv's in the first place to give more fuel in the lines to feed the injectors what dv's don't do is change the pressure in the lines when changed only the cc's of fuel going into the lines.
 
Laser Cuts, but you will lose mileage and have high EGT's, it will be harder to tow without getting hot. How come all you want to do is blow smoke?
 
Delivery valves "add" fuel but simply removing less from the line. Some do flow better than others though. Since liquid are essentially incompressible the fuel that is displaced by the plunger has to travel passed the delivery valve or be leaked out through the pump (meaning you plungers/barrels are bad).

The term "laser" seems to be used as a selling point lately. True full cuts have no shoulder, if they do then they are not a full cut despite what the marketing teams use as their sales pitch.
 
My truck ran in the 12's with nothing but a really light haze with custom lazer cut style dv's the whole smoke thing is all in how you tune I tuned my truck my self and set it up my self but did use info and suggestion on some stuff to optimize what I was doing which I thank smokem and other on here and for I miss my truck hope it is still running strong up there in Kzoo Michigan.
 
Way not get the extra 90cc from bigger injectors instead changing from 191 to full cuts? How to do the decision if you go for a bigger injector or a bigger DV?

Ride42 Which is the book you have take the picture of?
 
loganp said:
Laser Cuts, but you will lose mileage and have high EGT's, it will be harder to tow without getting hot. How come all you want to do is blow smoke?
Click to expand...

Cause thats the cool thing to do yo
 
my truck didn't lose any mileage and towed fine at a low egt and I had 5 x 16 injectors full moded out body's with the custom dv's and the hole in the end of the holder edm'd out to match the stock injector line id. and I towed a 5600lb cabin cruise to lake michigan all summer long plus towards then end of having it towed the frame's for fith wheel campers and travel trailers 38 foot long stacked 4 to 6 high depending on frame with out high egt's or bad mileage.
 
nilsson said:
Way not get the extra 90cc from bigger injectors instead changing from 191 to full cuts?
Click to expand...

Because the pump will only move so much fuel, and there gets to be a point where the injectors are so big that you aren't using the injector to its full potential without the pump flowing enough to keep up.

Atchley said:
Cause thats the cool thing to do yo
Click to expand...

I'm having a hard time telling if your serious or sarcastic.
 
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