Pump timing

Plus, how much is being drilled out of the DV holders? Just enuf to keep the shoulder of the DV in?
 
i forget what I drilled my holders out to. not much, I mean its just a lawnmower:poke: . The pumps, before being sent to a pump shop are only about 30 cc of fuel and only 100 cc after being maxed by a pump shop so a fuzz bigger than stock should suffice, not that it matters until the injectors are modified and you buy new lines anyway.
 
I tried to open the lower pic in paint too but I couldn't get it to work either. I see the shoulder in the middle of the valve. So just chuck the valve in the lathe and turn that shoulder off? Any idea how much more fuel that will give? Not that it matters much because I'm sure any will help, but I'm just curious.

I pulled it again last weekend. Turns out my waste gate was opening and bleeding off boost. I put .006" of shims back under the pump to try. I made 36# of boost and the EGTs stayed in the low 1700s. Could probably handle more water now that it is making more boost. I'm pretty happy with how it ran but there is still more to be had by tuning I think.

Here is a video;
[ame="http://www.youtube.com/watch?v=uZ2rwcf8Noo"]http://www.youtube.com/watch?v=uZ2rwcf8Noo[/ame]

This was the last pull for the year. I still have lots of little things to try next year.
 
Farmallgray said:
I tried to open the lower pic in paint too but I couldn't get it to work either. I see the shoulder in the middle of the valve. So just chuck the valve in the lathe and turn that shoulder off? Any idea how much more fuel that will give? Not that it matters much because I'm sure any will help, but I'm just curious.

I pulled it again last weekend. Turns out my waste gate was opening and bleeding off boost. I put .006" of shims back under the pump to try. I made 36# of boost and the EGTs stayed in the low 1700s. Could probably handle more water now that it is making more boost. I'm pretty happy with how it ran but there is still more to be had by tuning I think.

Here is a video;
http://www.youtube.com/watch?v=uZ2rwcf8Noo

This was the last pull for the year. I still have lots of little things to try next year.
Click to expand...


Correct, just cut the shoulder off.
 
I'm done pulling for the year now. I'll probably wait till spring to do anything with it now.
I'm working on building another tractor (gas) for next season so the diesel is low priority.
 
Seriousdiesel,
I was reading the service manual and it explains how the DVs work. I'm not questioning that removing the shoulder will work, but I'm trying to learn and understand how it works.

In the manual, that shoulder is called the "relief plunger". And here is how the function of the DV is explained;

The delivery valve prevents the fuel from flowing
back into the delivery chamber through
the injection pipe. It also prevents the fuel
from dribbling at the injection nozzle.
When the delivery stroke ends, the relief plunger
moves into the bore of the valve seat and seals
the delivery line from the delivery chamber.
The relief plunger lowers further until the valve
seats suck back the fuel to prevent dribbling
at the injection nozzle.

I think I can see how it will give more fuel; because the fuel will start flowing to the line faster and then flow a bit longer. In other words the DV opens sooner and closes later, correct?

So I guess my question is, why is that shoulder there in the first place?
 
that shoulder should have a flat spot that acts like an orfice to control the amount of fuel passing through. If you grind the shoulder you dont restrict the flow and allow a larger volume of fuel to pass through the DV. search Delivery Valves in the 94-98 dodge forum and youll find a ton of info. the dv in the p pump are very simmilar to whats in your engine and cutting the shoulder does make a difference.
 
Now I'm about googly eyed from all that reading over several days ;-)

It looks like there is a lot of factors involved with delivery valves. At the moment I'm a little concerned that it might make my EGTs pretty high since I'm already running 1700+. So I think I'll try more water to see if I can lower them first.


I think I'm also going to change the switch that activates the water to raise the boost pressure that the water comes on at.

I definetly want to give it a try. I'm just trying to apparoach everything very carefully so I don't burn things up.


I'm also wondering if there are bigger factory injectors that will bolt on. I'm wondering if they would make a difference too along with the DVs.
 
I had John Link work my injectors before he passed away. He said there's not alot you can do to that style injector. He said he did some grinding on the needles if I remember correctly.
 
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