Gen 1 Cummins Bosch VE rotary pump teardown.

Discussion in '1st Generation Cummins' started by alienturtle, Jul 19, 2011.

  1. alienturtle

    alienturtle Human

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    Now i know all of you opened this thread hoping that you would see the insides of a ford injection pump. Sorry to disapoint you but what you will see here is a Bosh VE rotary pump from my 5.9 cummins. I decided to post this is the IDI forum because it is REALLY neat and im going to try to explain how a rotary pump works and show you some parts of it. These guys are known to leak from the throttle shaft o ring so i purchased a bosh rebuild seal kit and just decided to do the entire thing. I have never pulled one apart before and i know people :eek: about doing it but i say go big or go home :)

    First i will start with the fuel pin. In a VE pump this is how they meter fuel based on boost pressures. A rubber diaphram attaches to the top of the pin and then goes into the top of the pump. Boost pressure from the manifold is pushed on top of the diaphram which pushes down on the pin in the bore. as you can see the ramp on the pin starts fat at the bottom and gets less and less as it goes up. Inside the pump there is a little pin that sticks out of the bore and rides up and down on this ramp of the fuel pin. On the left you have a stock un modified fuel pin. On the right you have a DennyT stage 2 fuel pin. Big difference in ramps. the more that fuel pin gets pushed down, the more the pin in the bore moves outward the more fuel you are flowing :)

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    Here we have the pump pretty much torn down

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    This is a picture of what they call the "full fuel adjustment" Its the same thing as the little allen key inside our ford pumps. From the factory you can see the "stop collor" that they spot weld to the screw so you cant turn it up anymore. With the help of a screw driver and hammer the collor busts right off and you can turn the pump up even more :)

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    Here is the actual pump with the AFC top removed. (AFC is the piece that the rubber diaphram and fuel pin ride in) The gear you see if the governor gear and weights. As RPMs raise the weights go out pushing on a shaft which pushes on the govnr assembly. The govn assembly is the black square thing in the second pic. Now these trucks stock have a 2700rpm govn spring in them that pushes back on these weights. You can change this spring out for a "366" spring that moves the gov rpm up to 3200RPM

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    Down inside the very bottom of the pump is the vains of the actual pump. Looks exactly like a rotary holly fuel pump. Attached to that is the actuall shaft you see on the outside of the pump

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  2. alienturtle

    alienturtle Human

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    Here is the pump cam. This is where it gets interesting. Not only does the pump spin it goes up and down on the rollers and cam you see here

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    In this pic the piece that is in the top right corner is the "head". the springs sticking out of the head are the return springs for the up and down cam that i just showed you. Another shaft goes inside this head with grooves cut in it. Inside the head itself there are holes drilled in different off places. Then when the shaft spins and goes up and down thats how it delivers fuel to different cylinders via the off drilled holes in the head.

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    really neat i think... just thought i had to share!!!
     
  3. towcat

    towcat Administrator Staff Member

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    allen-
    thanks for taking the time to document this;Sweet
    I'm going to move and sticky this thread over to the dodge 1st gen in a little bit when I get into the office.
    thanks!
     
  4. icanfixall

    icanfixall Official GMM hand model

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    Blurry pictures really suck.....:angel: But I'm impressed with all the exposed internals anyway. Its really a terrific amount of engineering thats goes into one of these pumps. Deiesl being a thin slippery fluid is much more difficult to pump than gasoline or water. So tollerances needs to be closer. Where I one worked on major fuel systems to the large boliers in the geanerating station. The bunker grade fuel oil turned solid around 102 degrees. Talk about a messy crude to work with. If it got on your work clothes you just throw them out. Nothing would cut it. Try to wash them and the home washer on hot water.... Nope. Everything gets painted fuel oil black.... then the wifey blows a big gasket you never are allowed to forget......:mad:-cuss:fight::idiot::oops::sorry::fan::kick:;Pissed Yeah.... That day will never be forgotten by me... But she can wash her horse blankets in the same washer I wash my clothes in. Talk about scratchy hir in your clean clothes.... Nope.... Can't say a thing... Just another reason I'm hopefully winning the race to the grave with her....:angel:
     
  5. alienturtle

    alienturtle Human

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    are the pics that blurry?? They look fine on my computer :dunno
     
  6. towcat

    towcat Administrator Staff Member

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    gary-
    not everyone is perfect like you. :rotflmao:rotflmao:rotflmao
     
  7. Bytesmiths

    Bytesmiths Registered User

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    Where did you get the rebuild kit?

    I have a Bosche VE from a Volkswagen that I'd like to learn on before ripping into a working one.

    I've used a lot of biodiesel, which tends to dissolve natural rubber parts over time. ALL my VEs leak around the accelerator shaft!
     

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