HELP need to have pistons machined!!

1. samco77on Regular Poster Joined: Oct 2008 Portsmouth Posts: 265 2002 106 GTi

   #1 31st January 2009, 18:01

   as some of you may know (from my progress blog) that i am putting a jp4 head on my j4 block, with 708's and jp4 (thinner) headgasket.
   
   i was talking to matt @ QEP the other day and he told me that clearance was too close to call, so i am going to get my pistons machined. as they need bigger cut outs.
   
   does anyone know exactly howmuch bigger to make them? im assuming they dont need to be deeper, as the ones on the exhaust side dont need anything doing, as JP4 exhaust valves are the same size as all the J4 valves.
   
   so do the cutouts need to just be made the same size as the inlet valves? or do they need to be deeper aswell??
   
   pics/details/exact sizes anything will be very helpful.....
   
   Cheers
   Sam
2. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

   #2 31st January 2009, 18:05

   why not just ask matt to do it?
3. williamsvts Saxperience Post Whore Joined: Feb 2006 northumberland Posts: 7693 pulsar gtir, mk4 astra sxi

   #3 1st February 2009, 10:15

   didnt someone no ssc measure that they had 0.6mm more clearance with this setup?
4. AlexR Saxperience Post Whore Joined: Aug 2004 Kunt & Sorrey Posts: 5763 Rep mobiles & Joes ma

   #4 1st February 2009, 11:04

   I answered this on 106 moaners...
5. samco77on Regular Poster Joined: Oct 2008 Portsmouth Posts: 265 2002 106 GTi

   #5 1st February 2009, 15:46

   yeh i saw that, didnt realise it was you. so you think the clearance will be ok?