Governor Spring/VE Info Threads Merged..

[BushWakr - RIP]

I have pasted, in 3 parts, the following text file on the VE pump. It was compiled by another 1st Genner who has given his permission to copy and use on our site. The credit goes to OkieBronkrider, moderator on the DTR site... thanks 'Okie..

Let me apologize in advance for being presently unable to post accompanying pictures that are referenced in this excellent post.


Unlike Delphi, Lucas or Stanadyne pumps. The rollers on the VE pump are not actuated by an internal cam ring with lobes on it, but instead the cam ring circular and attached to a round cam plate. As the cam ring rotates with the injection pump driveshaft and plunger, the rollers (which are fixed), cause the cam lobe to lift every 60* in a six cylinder engine. In other words, the rollers do not lift on the cam as in a conventional system, but it is the cam ring that is solidly attached to the rotating plunger that actually lifts as each lobe comes into contact with each positioned roller spaced apart in relation to the number of engine cylinders. With such a system then, the plunger stroke will remain constant regardless of engine rpm. At the end of each plunger stroke, a spring ensures a return of the cam ring to its former position. Therefore, the back and forth motion of the single pumping plunger is positive.

The sequence of events in a VE pump. The fill slot of the roatating plunger is aligned with the fill port, which is recieving fuel at transfer pump psi as high as 7 bar (100psi), one cylinder only.

The rotating plunger has reached the port closing position. The plunger rotates a control spool regulating collar. The position of the regulating collar is controlled by the driver through linkage connected to and through the governer spring and flyweights. Therfore, even though the roller may be causing the cam ring plunger to lift, the position of the regulating collar determines the amount of travel of the plunger or prestroke, so the actual effective stroke of the plunger is determined at all times by the collar position.

As the point of plunger lift (start of effective stroke), fuel delivery to the hydraulic head and injector line will begin in the engine firing order sequence.

The effective stroke is always less than the total plunger stroke. As the plunger moves through the regulating collar, it uncovers a spill port, opening of the high pressure circuit and allowing the remaining fuel to spill into the interior of the injection pump housing. This then is port opening or spill, which ends the effective stroke of the plunger

With the sudden decrease in fuel delivery psi, the spring within the injector nozzle rapidly seats the needle valve, stopping injection and preventing after-dribble, unburned fuel, therefore engine exhaust smoke. As the same time, the delivery valve for that nozzle located in the hydraulic head is snapped back on its seat by spring psi.

One thing to always remember is that the force of the governor spring is always attempting to increase the fuel delivery rate to the engine, while the centrifugal force of the governor flyweights is always attempting to decrease the fuel to the engine. Anytime that the centrifugal force of the rotating governor flyweights and the governor spring forces are equal, the governor is said to be in a state of balance and the engine will run at a fixed steady speed. ...

Continued .....

Bob