Injection pump camplate - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• Injection pump camplate by Hey on 23 Mar, 2006 21:34
• I searched through the site but didn't find the information I wanted.
  
  1)Is there a difference in camplate between early 1.9td (1993-1995½) and 1.9td(1995½-1997½)?
  
  2)A camplate with more lift will give more fuel right(td)? but will it produce less torque for a same fueling?
  
  
  I'm asking that because I think the early 1.9Td makes more milleage in general and if I am right, they also have greater camplate lift!  (this could just be an illusion but i'm asking anyway)
  
  Thanks!
• #1 by HP on 23 Mar, 2006 21:47
• What is the camplate, btw?
• #2 by X@V on 24 Mar, 2006 14:10
• Hey: I will show you the difference when I will disassembly my early 1.9TD's pump.
  
  The TDI plunger fits into the 95 + camplate.
• #3 by Hey on 24 Mar, 2006 14:19
• this is the hydrolic head of the pump
  
  
  
  and this is the camplate. At the right, there is a 1.6Td camplate et the left is an early 1.9Td camplate (thanks tp X@v for the pictures)
  
  
  
  So the "rod" in the middle of the hydrolic head is turning AND back and foward in the hydrolic head. The fuel is skeezed in the head and then distributed in the good cylinder at the best moment.
  
  1)Now, the 1.9TD camplate has more lift... it will skeeze the fuel farther.
  but.....
  
  2)THere is also a sleve OVER the "rod" which is covering holes. When the holes are covered by the sleeve.. the fuel is stock in the head of the pump and thus the only exit of the fuel is the injectors.
  
    When the camplate push the "rod" at a certain position in the head, the sleeve (which is fixed by your right foot uncover the hole. At this time, the fuel can get out of the head by this hole and the injection then stops.
   
    When you push your right foot farther, it takes more time for the sleeve(which is now farther) to uncover the hole and the injection last longer.. you then go faster.
  
    So a camplate with more lift has the possibility to inject more fuel than a camplate with less lift. For it, you need to be able to adjust the maximum position of the sleeve. This can be done easily by turning the well know fuel screw.
    Another thing to consider(which will not be important here) is the RPM range, a camplate with greater lift will travel much more thus being accelerated much more also. At a certain point, the camplate may not have time to comme back to it's rest position and you may have problem to go above 5000RPM.(stronger spring can be used)
  
  3)Now the timing of the injection is also important because we want to have the most efficient combustion possible. Two things must then be considered
  
  a) We want the greatest part possible of fuel to be burned in the position of the cylinder where the greatest torque is produce. i.e. where the lever arm created by the piston, rod, and crank pin is an angle around 90°.
  
  b)we also want all the fuel to be burned... and the maximum pressure is created at TDC.. so we must inject in advance the fuel, not to much because we want it to be burned has mentioned in a) but enough to burn completly
  
  .....if I explained well enough, you should now understand that a timing of 1mm, may not always be the same effective timing INSIDE the engine.
  
  
  now... the question was to know if the lift of the camplate could change the effective timing enough to change the efficacity of two engine with the same pump timing!!!!!!!
  
  the thing is... when a cam has more lift, his slope is greater (because the distance between injection must stay the same).
  
  For example.....at 1mm of lift, the pump with the smallest lift inject fuel later (effective timing retarded) and the pump with the greatest lift inject fuel sooner because the slope is more abrupt.
  
  So... want is the best setup according to a certain timing....??!?!?! this is want I want to know
• #4 by X@V on 26 Mar, 2006 23:11
• Hey, these are my pictures  :lol: The hydraulic head comes from a TDI with my old 1.6TD's springs (I now have early 1.9TD's springs)
  
  The 1.9TD's camplate has a 3.2mm lift. The 1.6TD's one has 2.2mm.
  
  The 1.9TD's camplate slope is really greather than the 1.6TD's one. When you check the timing on a 1.6TD, you need to move the crank on few degrees more than the 1.9TD because the slope is not the same.
  
  For the springs, the Cummins 4BT are better than stock 1.9TD springs.
  
  Check the Malone's pump. It has the 1.9TD's camplate and the engine can rev over 6000 RPM!  :wink:
• #5 by malone on 27 Mar, 2006 00:46
• Quote from: "X@V"

  Hey, these are my pictures  :lol: The hydraulic head comes from a TDI with my old 1.6TD's springs (I now have early 1.9TD's springs)
  
  The 1.9TD's camplate has a 3.2mm lift. The 1.6TD's one has 2.2mm.
  
  The 1.9TD's camplate slope is really greather than the 1.6TD's one. When you check the timing on a 1.6TD, you need to move the crank on few degrees more than the 1.9TD because the slope is not the same.
  
  For the springs, the Cummins 4BT are better than stock 1.9TD springs.
  
  Check the Malone's pump. It has the 1.9TD's camplate and the engine can rev over 6000 RPM!  :wink:

  
  
  I can only rev to ~5,100 RPM with the 1.9TD camplate and if I recall correctly 1.9TD springs. Need stiffer springs. I used to rev past 6,000 RPM with a 1.6TD camplate.
• #6 by Mechdonald on 31 Mar, 2006 16:27
• here is a small cross section of a pump
  
  
• #7 by hillfolk'r on 01 Apr, 2006 13:45
• its not a big deal,,and i dont wanna sound like a know it all,,but ibeen reading some stuff,,and  according to these aircraft test engine papers i got,,,you want max cyl pressure  to occur by 20 deg after tdc,,,thats where the power is,,,,sooner,and its tryin to fight itself,,later,,,,nopower,,,,,
• #8 by X@V on 01 Apr, 2006 22:30
• What are you talking about?