Piston bore wall thickness checks | The Z Club of Great Britain
  1. The Z Club relies on the support of it's paid members - join the club or renew your membership here.

Piston bore wall thickness checks

Discussion in 'S30 (240Z,260Z,280Z) Engine' started by Turn & Burn, May 30, 2019.

  1. Turn & Burn

    Turn & Burn
    Z Club Member

    I’ve just finished a long evening in the garage carrying out sonic thickness checks the bore walls prior to buying pistons for a rebore. I guess I hoped I would have a block good for an 89mm piston (3mm wall thickness after boring) but I believe that’s a rare block these days. I have a few readings that wouldn’t support a 3mm wall thickness at 89mm and just a couple of marginals at 88.5mm, so it’s probably going to end up at 88mm, is the 88.5 too risky?
    I’ve attached a pic of the results, just wondering if anyone else has similar data and what size you ended boring to?
     

    Attached Files:

  2. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    What block is it? F54 or n42? I just closed my eyes and went for 88.5 on my f54 block.
     
  3. Turn & Burn

    Turn & Burn
    Z Club Member

    N42, With siamesed liners.
     
  4. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    Did it have liners when you got it?
    From my reading of the Internet, I'd think you'd be safe at 88.5
     
  5. Turn & Burn

    Turn & Burn
    Z Club Member

    Sorry, I meant the original block was the siamesed block. It’s not been re-sleeved.
    You’re prob right with the 88.5mm being good, I’ve just done the engine calculator on both bore sizes it only about 40cc larger for the extra 0.5mm. I’ll see what pistons are avail and make a call.


    Sent from my iPhone using Tapatalk
     
  6. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    And 88.5 gets you to a genuine 2.9 litre. 88 and your still driving an L28 (if you're using an L28 crank!)
     
  7. johnymd

    johnymd
    Z Club Member

    Which pistons did you go for in the end?
     
  8. Turn & Burn

    Turn & Burn
    Z Club Member

    88.5mm JE pistons from Rebello, I’ve been away for a while so they’ve not been posted over yet. Similar price to buying in the UK after u factor in duty etc. but Dave (Rebello) knows all the valve cutout dimensions that the UK JE Pistons dealer was missing (Performance Unlimited).
     
  9. johnymd

    johnymd
    Z Club Member

    That's exactly how I bought mine. Contacted Dave and he bought the pistons for me then put them with an engine coming over here.
     
  10. status

    status
    Z Club Member

    Robably with my Engine Jon,Makes sense
     
  11. johnymd

    johnymd
    Z Club Member

    They came with Dean’s engine last year.

    You’ve got me thinking though Paul.
     

Share This Page