Sooo, . . . . . Has anybody tried replacing the . . .

[BC847]

. . . . . VE's, stock/OEM overflow restriction with that from a PeePump or something similar?

Overflow restriction
The overflow restriction (Figure 6) is screwed into the injection pump’s governor cover and connected to the pump’s interior. It permits a variable amount of fuel to return to the fuel tank through a narrow passage. For this fuel, the restriction represents a flow resistance that assists in maintaining the pressure inside the injection pump. Being as inside the pump a precisely defined pressure is required as a function of pump speed, the overflow restriction and the flow-control valve are precisely matched to each other.

It provides a means of minimum fuel flow for the purpose of cooling the IP as well.

Soo .. .. what if one were to modify one's existing restriction by adding an adjustable spring-loaded regulator in series?
- At a minimum fuel demand number (idle, light part-throttle maybe), the regulator would be open venting fuel from the restriction, back to the tank.
- Increasing the fuel demand greatly might drop case pressure having the regulator close. The idea being that fuel that would otherwise go to the tank, would be made available to the H/R (closing the return would help maintain a minimum case pressure).


I wonder how the dynamic injection event timing circuit would respond.


Looks like it has been done for specific applications:

Low-pressure stage
Low-pressure delivery
The low-pressure stage of a distributor pump fuel-injection installation comprises the fuel tank, fuel lines, fuel filter, vane-type fuel-supply pump, pressure control valve, and overflow restriction. The vane-type fuel-supply pump draws fuel from the fuel tank. It delivers a virtually constant flow of fuel per revolution to the interior of the injection pump. A pressure-control valve is fitted to ensure that a defined injection-pump interior pressure is maintained as a function of supply-pump speed. Using this valve, it is possible to set a defined pressure for a given speed. The pump’s interior pressure then increases in proportion to the speed (in other words, the higher the pump speed the higher the pump interior pressure). Some of the fuel flows through the pressure regulating valve and returns to the suction side. Some fuel also flows through the overflow restriction and back to the fuel tank in order to provide cooling and self-venting for the injection pump (Fig. 2). An overflow valve can be fitted instead of the overflow restriction.

Thoughts?

[turboram]

Pe pump overflow is regulated at one pressure.. so I dont see that working. More fuel is bypassed in the case pressure regulator than the overflow it starts opening at 50 psi the ksb counter acts this but up untill a set pressure in the ksb then opens, that pressure is unknown to me but I will investigate. I think that ksb pressure relief could be raised then no fuel could be bypassed at any rpm. Then the overflow orifice could be a on a wot switch to close it then all fuel that the vane pump delivers could be used. The other way would be to plug the case relief and overflow orifice and use a boost reference regulator set at 3 to 1 like a fuel injected car would use

[oldestof11]

Thought about it and think you can get an adjustable regulator and adjust it accordingly.

[BC847]

Pe pump overflow is regulated at one pressure.. so I dont see that working. More fuel is bypassed in the case pressure regulator than the overflow it starts opening at 50 psi the ksb counter acts this but up untill a set pressure in the ksb then opens, that pressure is unknown to me but I will investigate. I think that ksb pressure relief could be raised then no fuel could be bypassed at any rpm. Then the overflow orifice could be a on a wot switch to close it then all fuel that the vane pump delivers could be used. The other way would be to plug the case relief and overflow orifice and use a boost reference regulator set at 3 to 1 like a fuel injected car would use

Take the Cold Start Assist (KSB) out of the equation as I'll be removing mine.

With that, we're left with the vane-pump, it's now simplified pressure regulator, the overflow-restriction, and the dynamic timing advance device.

- While the stock/OEM PeePump Overflow-Valve is fixed, there are adjustable aftermarket devices available. There, it's a question as to whether they can be set to a pressure that suits the VE.
- The vane-pump's pressure regulator can be adjusted.

In my head, those two items above can be adjusted so as to raise the case pressure. Such might improve H/R fill-time at higher engine RPM.
Shims and/or a different spring in the timing advance piston could better dial-in the advance curve (stroke start point, full advance stroke point, stroke span).

Thought about it and think you can get an adjustable regulator and adjust it accordingly.

It may be just that simple, Jon.

The thing is, at what point would I want the overflow to close? The driving thought is that with big injectors, one might assume the case pressure is gonna drop at WOT and the engine wound-up (the vane-pump's regulator should be closed at that point and not venting excess pressure). It's there I think the overflow should close to divert that fuel to the H/R.
- Now take you foot off the throttle and let the engine come back to idle. The case pressure should come back down to a minimum pressure based on the vane-pump's speed. If this case pressure is higher than that illustrated above, then the overflow valve should open (or regulating).

I suppose if we weren't using a dynamic timing device, perhaps the above might be simpler.

- I want to retain the dynamic timing advance function.

I gots ta hook-up my gauges and light.

[RCCUMMINS89]

David, me and a buddy have something in the works that would be perfect for a non ksb truck. One can simply make an adjustable timing spacer and therefore have an external adjustment for the timing spring, dynamic, and the overall allowed amount.

[BC847]

David, me and a buddy have something in the works that would be perfect for a non ksb truck. One can simply make an adjustable timing spacer and therefore have an external adjustment for the timing spring, dynamic, and the overall allowed amount.

A threaded/sealed penetration into a KSB cover-plate thingy and a knob on a threaded shaft working a spacer/plug inside (working up against the spring).

I'm in.

Shut-up and take my money.

[RCCUMMINS89]

Well.... I have a buddy that does my machining for the company (soon to be fuel pin, the fuel screw, hopefully timing doo hicky).

So since you have the perfect truck/set up/pump/know how to actually put something like this to use. Let me know what needs to be done and I'll have you be the free tester. Where I'm at is I don't know what style of o ring/sealing system to make work.

Otherwise it is as simple as a shim style washer on the end (inside) and a modified ksb blocker cover with a threaded bolt running through it.

[BC847]

Thinking out loud:

Since you're making fuel-screws, perhaps modify one of those to a cover-plate with a threaded section like that in the IP top.

Isn't there a port in the blank cover-plate that vents spring-side fuel pressure back to the top of the regulator? We'll need that to keep the dynamic timing

[RCCUMMINS89]

I was thinking exactly like the fuel screw.... same style of o ring and then have a threaded spot that is extra long so that the o ring stays covered by thread for the whole distance of allowed travel.

I was hoping you would know on how the fuel relief works. I have personally never seen a deleted ksb with the dynamic timing. This is also where I would need your help on the matter, seeing is how you want to delete the ksb while keeping the timing.

[BC847]

Never mind. That port is part of the case . . . . .





The cover-plate should be no more than this . . . .

[RCCUMMINS89]

Oh, ok.... so we good with just blocking it off? Now what is needed on the opposite side of the ksb tube?

[BC847]

That same plate.

[RCCUMMINS89]

I mean the fuel transfer tube that goes from the ksb back up to the vane pump regulator doo hicky. What is needed to do away with that tube after the ksb is deleted

[BC847]

I mean the fuel transfer tube that goes from the ksb back up to the vane pump regulator doo hicky. What is needed to do away with that tube after the ksb is deleted

A different regulator . . .

KSB regulator on top, NON KSB regulator on bottom . . . .

[RCCUMMINS89]

Ok.... then this should be an easy thing to do.


What I plan on doing is making a block off plate that doubles as a timing spacer that is twice as thick as the M&H one. Then have an adjustment that has the has the ability to be turned in to where a stock truck and timing set up would be and then backed off up to a double the "normal" spacer distance.

Suggestions on that? Also on these regulators, if one were to just swap in a diff. would it throw off the case pressure from what it was stock (are these adjusted when the builder builds the pump)