pump assembly questions - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• pump assembly questions by carrizog60 on 21 Jul, 2011 05:42
• hi
  
  can someone explain me this quote seen on the pump assembly topic?
  
  

  Quote

  It's the cams (humps) of this plate that cause the piston's movement when the rollers pass over them.  The piston moves, compresses the fuel and injection occurs.  You can modify the advance by turning the roller carrier in relation to the timing advance piston's position underneath.
  

  
  thanks
• #1 by Mark(The Miser)UK on 21 Jul, 2011 06:08
• Quote from: carrizog60 on 21 Jul, 2011 05:42

  hi
  
  can someone explain me this quote seen on the pump assembly topic?
  
  

  Quote

  It's the cams (humps) of this plate that cause the piston's movement when the rollers pass over them.  The piston moves, compresses the fuel and injection occurs.  You can modify the advance by turning the roller carrier in relation to the timing advance piston's position underneath.
  

  
  thanks
  

  
  What's wrong with turning pump body relative to pump pulley?
• #2 by rabbitman on 21 Jul, 2011 11:02
• Quote from: Mark(The Miser)UK on 21 Jul, 2011 06:08

  What's wrong with turning pump body relative to pump pulley?
  

  
  X2
• #3 by regcheeseman on 22 Jul, 2011 03:43
• maybe because one is static and one is dynamic?
  
  I believe the OP's confusion is that it doesn't actually make sense.
  
  You can modify the advance by turning the roller carrier in relation to the timing advance piston's position underneath.
  
  Unless you consider that the use of the wording  'turning' may relate to the process of removing material with a lathe?
  
  However, whatever it means, it seems a odd idea?
• #4 by carrizog60 on 22 Jul, 2011 05:02
• my question is that can we,at assembly,modify the advance by rotating the carrier original position.
  and,if one decides to shave the pump body to allow more travel,how much is good/safe?
• #5 by theman53 on 22 Jul, 2011 05:56
• I think this is exactly what Giles said he does in his pump building procedure. You would probably have to buy one of his pumps to know exactly how much to take off as that is his living and he probably won't disclose that much info.
• #6 by carrizog60 on 22 Jul, 2011 13:35
• assuming that timing advance is somewhat linear across the rpm range were does the piston hit the pump body?at what rpm?
  knowing the travel vs rpm we could know how much shaving is needed to have advance timing to more high rpm
  
  or am i just talking and having no sense?
  
  i know giles is the man overseas but i am from portugal and no pump builder at any way lol
• #7 by rabbitman on 22 Jul, 2011 18:38
• I think if you grind the aluminum where the roller carrier/advance piston pin goes you can get more travel, but you might have to machine the timing piston cover to allow even that much travel.
  
  If the roller carrier rotates too far it will hit the governor gear and metal shavings are bad bad bad inside an IP.