Here's the idea, cutting down the vein pump inner race and or adding some veins to attempt to keep case pressure up while at higher RPM's. My thoughts are that the gain of pressure wouldn't be worth the loss of volume as the extra veins would take up some room.

My next thought would be to add an external pump that is capable of high pressure and feeding it threw the FSS hole. But my question here would be how is dynamic timing affected by case pressure. I'd imagine stuffing 200 psi into the FSS while the truck is at an idle would not be good for dynamic timing as I'd thing it would go to full advance? So what can be done about this problem? I think some sort of check valve that once pressure drops on the injection pump side then it allows the belt driven pump to supply pressure back threw it to be able to keep case pressure up. Since our dynamic timing is what sets us apart from the Pee Pumps.

The reason on me trying to accomplish this is to figure out how to make the 14mm head live a long happy life.

I've read that a 12mm H&R with a 4 mm cam plate is capable to producing decent flow numbers, like 25% over stock. And using the "HD" return springs help keep the rollers from jumping off of the cam plate at higher rpm....Don't know if that is true?

I've also read that a 14mm with a 4mm is not ideal because it uncovers the spill ports also the ears rip off of the cam plate at higher rpm.

So as I read it, 12mm and 4mm or 14mm and 3.2mm.

I came across some old posts by Giles where he said he was testing using the 14mm with a custom plate, but he never posted much back up after he stated it.

Any of that make since?
Thoughts, suggestions, tell me to go buy a P Pump?

 

Giles is still around, just not here much. Go here: http://www.performancediesel.ca/contact.htm

 

I'll send him an email, but honestly didn't really think he would give up info since its kinda the way he makes money.

 

I never knew Giles was a member here!

Sorry, I don't have any answers for you, Justin. Which is why I'm just going to send a core pump to Giles and have him work his magic. I do know that, just as you said, he won't talk much about what he does to the pumps. He won't even give any info on the 12mm and 14mm he built for Aaron! I completely understand though.

 

Not here on 1stgen. And maybe not him, but someone that knew him well and knows some of his tricks.

 

I've gotten some measurements, don't see how adding veins will help, possibly raise pressure but I think volume will drop with added veins.
Here's the vein assembly; The black lines were an idea to add veins. But biggest problem I see is the one that is right over the key way, seems it would get real weak!

Here's the height of the vein pump, It's fairly thick and I think it may have enough girth to stand to have the inner ring turned down to allow more fuel?

Not knowing a dang thing about fluid dynamics I tried to understand but It's way over my head, I tried to get the volume of the pump as it sits, Static would have a volume of .1472", but this is the measurement with out veins in the inner ring. Adding a few extra veins into the mix I think would add to the problem of low volume. Thoughs?
Here is the next problem;

That's the inlet passage of the VE. Notice the check ball on the side, If you wanted to drill this out to allow more fuel in then I'd think you would need to knock that ball out and tap the case and put a hole plug in there. Thoughts?
Here is the inside of the case;

There is room to get more area for fuel to get in. But this takes us back to our first problem, is this all for not? If the vein pump can't be improved to keep case pressures up.
Here is my cam plate, this was the best measurement I could get.

So anyone gotz any Ider's? Besides clean the top on my nasty tool box on Monday, geeze that looks bad in the pictures!

 

Here is my idea for supply; Bare with me, not nice but gets the point across.

My problem is figuring out that check valve. Since I think I need case pressures lower before the 1500rpm range for timing reasons. So here's the question, does anyone know if there is some sort of valve that will allow pressure to flow how I need it too? VE side will have up to 200ish psi until it drops off, once it drops below the 100psi threshold I want the belt driven pump to supplement the drop in case pressure. Does anyone know if there is such a thing? Or throw out some idea's on how to make my Picasso painting above work?

 

I believe you are correct in thinking adding more veins would decrease the total volume of the fuel moved in one rotation of the pump (the volume of fuel decrease would match the volume of space the additional veins would occupy).
- One way would be to increase the overall inner diameter of the case that the rotor spins in, while maintaining the offset of the rotor (obviously, the reach of the veins would need to be such to reach the wall without over-extending and possibly binding in their slots).
- Another way would be to make the vein-pump assembly taller (currently .3915 as shown above). But now you're talking about a custom assembly that you'd still have to fit in with everything else.

It's my understanding that perhaps at a given rotational speed (and higher), cavitation comes into play. In my mind, opening-up those passages and even rounding some of the fuel passage sharp corners (NOT the pump itself) would lessen potential cavitation and result in a more consistent flow of fuel at the higher pressure differentials as the fuel made it's way through the assembly.
Increasing the volume of fuel through the transfer-pump would keep the pressure in the case up. The increasing demand for fuel as you lean on the pedal is what consumes the given volume of fuel provided by the vein-pump thus reducing the pressure in the case.

So what if one were to make a throttle activated switch that would fire a solenoid that temporarily closed off that metered bleed-port in the case? That would certainly put more volume of fuel back in the case during the WOT run. I wonder if the quantity of fuel then flowing to the injectors would still be enough to keep the IP cool.

 

the keyway could be moved inbetween the vanes.

drilling and dapping the inlet does not seam to be an issue.
and from what i read that is one of the biggest problems.

you can run 1 inch lines from the tank but iff the inlet is 5/16" well, whats the point?

wish i had a core to play with......... iam very interedted in modifying the pump but cores where i am are non existent.

by the way good post keep it up.

post in compd first gen section you might get more response.

 

I found some old posts by Ford1966(or somethig like that). He claimed he pushed 70+ psi into the inlet of the pump, and the vein pump came apart. He also claimed to have turned down the inner ring, didn't tell how much, but it allowed the vein to go sideways and seized, again.
I've found some places that opening up the passages would be possible. I do plan on doing just that.
I've also found old posts by Cummins King where he smoked one of his pumps attempting to supply fuel into the "out" banjo bolt on the back of the pump. I'm not sure if he just blocked it completely off or is he had some sort of check valve. But I'm sure his pump got plenty hot with no return.
I suppose the question is really if there is much fuel returning at high RPM, or if it's getting pushed to the injectors at that point?
Information I've found was very vague. Most of it was back when they were all attempting to top KTA, so information was shared but kept secret at the same time....if that makes since? And now most of them have moved on to inline pumps.

 

Adding to BC847's idea of enlarging the case diameter or thickening the vein plate, could you also not reduce the vein plate outer diameter? This would achieve the same as increasing the case diameter.

Adding veins will only reduce leakage losses if there is any while reducing volume output. Added veins would also reduce output pressure pulsation (not usually a concern with vein pumps).

The volume is the area between veins, not many ways to change that. Anything to increase the volume between veins will increase output but at what cost?

I am new to this exact pump but not pumps in general, why does the 14mm not live to begin with? I assume the veins break and seize the pump?

 

Now, since i don't understand how the fuel return works can someone explain.

I assume the high pressure side of the VE is returned to tank? or is it from injectors to tank? Or is it to the suction side and not tank at all?

They do make switching valves which are pressure controlled (adjustable too) so it will allow flow from belt pump to ve when the pressure drops below a certain point, thats fairly easy (would require constant return to tank though when not feeding VE). Its the rpm level that is tricky.

EDITED: it was way too late and i missed a few things.

 

Ok you guys peaked my interest. I guess I haven’t thought about this enough. I have more pumps than I need and one of my good friends has a pump shop so you would think I would have experimented in this area a little more.
I have +/- zero internal modifications on the inside of my VE pump. (Maybe that’s why I am sucking hind tit in the HP race.) I guess I just need to break down and take one of my pumps apart and figure some things out.
I know there are some things that I could do to my pump that could potentially lead to some more HP. I spent 12 hours in the pump shop and didn’t gain one ounce of fuel. Talk about frustrating.

All I know is I have been through my fair share of 14mm pumps back in the day, but my current combination has been on for 25-30k and its still doing fine. Well it would be doing fine if I hadn’t lost #6 piston. I just got my block back from the machine shop yesterday so when I get sometime I will throw it back together. I hadn’t planned on doing any pump work while it is off I was just going to do something in the turbo department, but maybe I should look into a few things.

Keep up the good work guys. This is why I haven’t sold my heap yet. I haven’t found the limits.

Stomp

 

Mr. Stomp, Care to share information on what you have done about case pressure drop at high rpm? Are you just shoving high pressure into the inlet? What kind of pressure are you pushing? Also the H&R that KTA built for you, is it with a different cam plate, and are the delivery valves the stock ones? I understand if you don't want to give up the information, thought I would ask though.

Biltit, I was thinking about making the outer ring larger, but need check if the passages can be made to match the larger size. Both injectors and pump return back to tank. Back of the pump has a banjo bolt labeled "out" which returns to tank, that was the idea Dave was throwing out to help keep case pressures up. Here is the outter ring.


Do you have any names or links to the magical check valve I'm looking for? I intend to leave the return stock, and feed all the pressure threw the F.S.S. hole.

Does anyone have case pressure gauges on their trucks? I think we need to log some real numbers to find out what is really happening inside, rather than speculate.

 

Here is my crazy idea for more H&R flow: I want to block the original feed passage to the h&r, and feed high pressure into the shutdown solenoid. In my mind that would allow the case pressure to remain unaffected by fueling demands. I am not sure if the return fuel from the h&r would be enough to overwhelm the return and jack up case pressure though. If it did, it might be a first for too much flow in the case It even looks like the feed hole in the h&r is the right size for 1/8npt.