VE pump- figuring out loud

[dragrdan]

Pump Volume:
Basically as I understand it, the VE has a bore of 12mm, and a stroke of 2.8mm stock, which gives a volume of 316.7.

Increasing the stroke to 4mm, keeping the 12mm bore gives a volume of 452.4

Increasing the bore to 14mm, and keeping the 2.8mm stroke gives a volume of 431.1

Increasing the bore to 14mm, and the stroke to 4mm gives a volume of 615.8

These are all static volumes, and i figure that the fuel is under pressure going in, so, the actual volumes would be increased. Does anyone know what pressure the fuel is under before the actual injection shot? Is it case pressure? Since the bore and stroke remain constant, is the pressure difference at which it hits the head where we get the different volumes needed from idle to WOT?

Pump Timing Mods:
In reading about the VE on the VW sites, I came across a post where they were shaving 2mm off the timing piston(spring side) to increase the advance range, and using different springs to tailor the curve. Do these mods work with our pump, or is there an internal difference that prevents us from doing the same?

[Ace]

I don't really know any of that stuff, but it's gotta be at least a few thousand psi for injection.

[burnt_servo]

Pump Timing Mods:
In reading about the VE on the VW sites, I came across a post where they were shaving 2mm off the timing piston(spring side) to increase the advance range, and using different springs to tailor the curve. Do these mods work with our pump, or is there an internal difference that prevents us from doing the same?

i've got the url to the german website somewhere , where i first ran across this . ( if anyone wants i can try to dig it up )

and i can't see why this wouldn't work with the cummins ve pump .

the only thing that i can see not really working out , is the cummins is direct injection , the advance mods are for a indirect injection engine .......
what if the cummins injection system doesn't need the extra timing ?

the timing advance mod is so the vw engine can rev past 6000 rpm , and still be making power .

[seeker1056]

it does work - i have the parts in my pump from Giles in Toronto.

Pump would rev to 4700 rpm with a 4200 rpm spring

I have no doubt that with a different spring one could rev past that, albiet you would be out of fuel because the pump internals as such wont allow enough fill time to the head rotor.

For example on the stand my pump would make well in excess of 400 cc's till about 3000 rpm, and then steadily fell off to about 250 cc's at 3900 rpm, with no idea what it would make for cc's after that

Timing isnt everything but it helps, lol

You guys figure out how to full fuel the pump past 3000 rpm and then you can worry about timing and such

[burnt_servo]

You guys figure out how to full fuel the pump past 3000 rpm and then you can worry about timing and such

the govenor spring in a vw has 3 springs in it ( in a cage ) , and in a vw starts to defuel around 4500 rpmish , add some shims to 2 of the springs and defuelings starts to happen around 6000 rpm .

the vw part should be dam close to a direct drop in into the cummins ve pump .

[ford69557ci]

The VW pump runs a smaller h&r. The small h&r takes less time to fill than a 12mm or 14mm h&r that is why they keep the fueling at a higher rpm.

[burnt_servo]

The VW pump runs a smaller h&r. The small h&r takes less time to fill than a 12mm or 14mm h&r that is why they keep the fueling at a higher rpm.

h&r ? ....... it may seem obvious , but right now i have no idea what your talking about .


a stock vw pump won't run much past 4500 rpmish without 10 to 15 psi pressure from a lift pump

[Begle1]

The VW pump runs a smaller h&r. The small h&r takes less time to fill than a 12mm or 14mm h&r that is why they keep the fueling at a higher rpm.

h&r ? ....... it may seem obvious , but right now i have no idea what your talking about .

"Head and Rotor". The little micron-finished pumping element that we are intent on pressurizing fuel to 15,000 PSI 200 times per second.

[ahale2772]

kudos on your verbiage

[burnt_servo]

The VW pump runs a smaller h&r. The small h&r takes less time to fill than a 12mm or 14mm h&r that is why they keep the fueling at a higher rpm.

h&r ? ....... it may seem obvious , but right now i have no idea what your talking about .

"Head and Rotor". The little micron-finished pumping element that we are intent on pressurizing fuel to 15,000 PSI 200 times per second.

that is what i thought he was talking about , but i thought i should ask just in case it ment something else .

[seeker1056]

I htink you missed the point

Runnin outa fuel because of lack of fill time is not the same as defueling

And in our case at 4700 rpm we had way less than 250 cc's of fuel for exactly that reason even though we started with over 400 cc's

You can crank your interanl pressure till your blue in the face but that is NOT gonna change the fill time enough to matter

You need bigger passages everywhere because you need volume as well as pressure

Hell we even edmed the head rotor tryin to make the supply passages bigger - but it isnt enough

Now if you did away with the internal pump supply altogether and tried to supply say 200 psi directly to the head from the shutoff port you might get somewhere, and it would get rid of the pesky seal issue, but then you also no longer have fuel inside the pump to cool it

A conundrum to be sure

[ford69557ci]

I always wondered about tossin a ton of pressure through the shut off port. I sold my truck before I got to try that. I had the same problem with my pump I had everything opened up as much as could be and it still could not keep up at higher rpm. I think there might be fuel to keep it cool if you ran 30 through the normal inlet and then 200 through the shutoff. The pressure shouldn't make it to the front seal since case pressure doesn't.

[Begle1]

Theoretically, when you put the high pressure, high flow fuel flow into the shutdown solenoid hole, you could block off the stock vent orifice and put a new vent orifice between the vane pump chamber and the pump case. Then remove the vanes from the pump; most of the fuel will enter the head and rotor directly, but some will flow through the case and out the stock inlet as a way of cooling and venting the pump.

[dragrdan]

The first part of the post was mainly thinking about modding the pump, but not going "all-out". We have all heard of the 14mm H&R/4mm camplate pumps, and the benefits/problems with them(and the fuel supply system needed to feed/cool it). I was thinking about changing either one or the other,(H&R OR camplate). From my figuring though, it seems that the camplate alone would yield better results than the H&R alone. Who has done one or the other, and what mods were needed to support it(fuel supply, etc...)

As far as the timing mod, I wasn't thinking about increasing the RPM range of the VE, but tuning it for better performance within the range we already have. Everything we do to the pumps is aimed at getting more fuel, and more fuel likes/needs more timing. And with different springs available, it could be tailored, much like the timing advance in a distributor for a gasser.

[burnt_servo]

I htink you missed the point

no i didn't ......