Full cut delivery valves???

[cummins12club]

Just wondering ic anyone runs or has tried To run full cut delivery valves if so how did it work out and exactly what was cut on the valves I've heard that delivery valves on a ve pump mainly control idle smoothness and that no improvements would be seen in my mind if ur putting out more fuel how could it not do something?

[BC847]

The delivery-valves on our trucks ARE full-cut.

[Tacoclaw]

Yeah, I've read that the Non-IC'd DV's are, but they seem to differ from the IC'd DV's in some way or another. Dunno what it is, it may not have anything to do with the cuts.

[cummins12club]

well i can tell you that between non ic and ic the delivery vlaves themselves and the springs are identicle the difference is in the lenghts of the holders, what do you mean David they already are full cuts?

[BC847]

what do you mean David they already are full cuts?

Yes.

[cummins12club]

How? Their is still a colar on the delivery valve where it rides in the holder from all my research a full cut is when that colar is machined completely off my other thought was on a p pump delivery valve that little plunger inside has a colar as well and that is machined down as well?

[ahale2772]

if the collar was machined down it wouldn't be a delivery valve

[oldestof11]

if the collar was machined down it wouldn't be a delivery valve

[cummins12club]

I'm sorry for the confusion I'm not attempting to argue just trying to learn and understand I inspected a p pump delivery valve today I was showed a stock one and a full cut on a full cut the little pluger inside the cylinder has a colar just beneath the head of the plunger and it was machined down to the rest of the shaft diameter and I was explained that that is what makes it a full cut so I checked out out d valves and the little plunger on our has the same colar as well why can it not be machined just like the p pump d valves?

[BC847]

The following image shows the delivery-valve components as found in my '93 VE injection-pump (TOP). The delivery-valve on the bottom is from another VE injection-pump . . . .





Looking at the plungers a little closer, one notices there's a retraction-piston on the left. Ours on the right, has this retraction-piston absent. It's my understanding the pee-pump DVs include that retraction-piston as stock/OEM. Folks pay good money to whittle on those up and to the point of fully removing it (full-cut).

Delivery valve
The delivery valve closes off the high pressure line from the pump. It has the job of relieving the pressure in the line by removing a defined volume of fuel upon completion of the delivery phase. This ensures precise closing of the injection nozzle at the end of the injection process. At the same time, stable pressure conditions between injection pulses are created in the high-pressure lines, regardless of the quantity of fuel being injected at a particular time.
The delivery valve is a plunger-type valve. It is opened by the injection pressure and closed by its return spring. Between the plunger’s individual delivery strokes for a given cylinder, the delivery valve in question remains closed. This separates the high-pressure line and the distributor head’s outlet-port passage. During delivery, the pressure generated in the high pressure chamber above the plunger causes the delivery valve to open. Fuel then flows via longitudinal slots, into a ring-shaped groove and through the delivery-valve holder, the high-pressure line and the nozzle holder to the injection nozzle.
As soon as delivery ceases (transverse cutoff bore opened), the pressure in the high-pressure chamber above the plunger and in the high pressure lines drops to that of the pump interior, and the delivery-valve spring together with the static pressure in the line force the delivery- valve plunger back onto its seat again (Fig. 11).

[cummins12club]

So your saying that ve delivery valves are already technically full cuts because that colar is already machined down from the factory on the plungers and theirs nothing else you can do with it correct? So if the lateral grooves are fuel channels would deepening them give the added effect of more fuel?

[ahale2772]

the collar you talk about is the seat, every delivery valve needs a seat othewise there will be no injecton even, maybe a sputter but not a crisp event. the "cut" portion of the DVwill flow differnt CC's, but ours are allready "full cut" so there is no advantage to modifying them

[cummins12club]

Right on but what about deepening the fuel channels? That would have to yield some effect not necessarily a positive effect but it would have to change the amount of fuel being injected

[AHineman]

http://www.1stgen.org/viewtopic.php?f=4&t=11537

[cummins12club]

Hmm if they are already full cuts then y did somebody say full cuts would flow 40cc at Roma below 1500?