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9A block from Audi 88



I actually thought the two 16V heads were essentially identical but a freind here who's a mechanic said he did this swap on his GLI before he rolled it a few years back and said that the difference is in the shape of the underside of the heads.  I'm going on his information so again, no tech manuals.  I have two PL heads and my 9A head so I figure it won't hurt if he's already done one.  He also is telling me to use the intake cam from the PL because it's a longer duration.  I'm thinking that an interference head is an interference head as long as the timing belt holds I should be ok...... I hope..... famous last words.

      Rave Racer
Currently:
NEW!!  91 Jetta GLI 2.0L 16V
'81 Scirocco Mk1 1.8L 8V Digifant 2

'89 Jetta GTX 1.8L 16V
'87 Audi 4000 Quattro 
 http://www.audifans.com/registry/view.php?action=viewCar&carid=110
'72 Triumph GT6
 http://www.triumphowners.com/uploaded/34/50-50-111014_20raveracer-gt6-1.jpg
 
http://spaces.msn.com/raveracer77/photos/ 
http://www.myspace.com/rave_racer
___________________________________________

  ----- Original Message ----- 
  From: Dan Bubb 
  To: raveracer77 
  Cc: scirocco scirocco 
  Sent: Tuesday, November 28, 2006 05:41 AM
  Subject: Re: 9A block from Audi 88


  My understanding is that the 9A had a slightly higher CR than the PL,
  like 10.5 instead of 10 (maybe simply due to the increased
  displacement), although I've seen other data stating the 9A was also
  10:1.
  But I don't believe the combustion chamber volume is different between
  the 9A and PL heads, so swapping heads would not change CR.
  OTOH putting an 8V head on a 16V block will really raise the CR since
  combustion chamber volume is only ~30cc instead of 45cc or whatever
  the 16V head is.
  Dan

  On 11/27/06, raveracer77 <raveracer77@yahoo.ca> wrote:
  >
  >    Actually the 9A was used for early FWD Audi 80's and 90's.  I've found parts for my GLI from them.  I beleive stock compression is 10:1 for mine but I'm not sure if the heads are the same.  The PL head (1.8 16V) on a 9A block should make between 12.1:1 to 13:1 depending on the head gasket.  I look forward to doing this in the near future as I already have all the parts.
  >
  >      Rave Racer