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.30 thou too much?

Discussion in 'Engine Building' started by Tait72, Jan 16, 2013.

  1. Tait72

    Tait72 Member

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    Hi I've got a long winded question concerning piston to valve clearances.
    I know claying is the way to accurately measure, but looking for experienced opinions for now, until that process takes place.
    I have a GSR head going on a GSR block with LS crank/rods and B16 pistons. The issue is the head had previous damage and has had to have 20 thou removed "since I owned it" so I would assume it had maybe 10 thou removed b4 I bought it.
    Is .30 too much with B16 pistons and stock B16 cams in a Gsr head.
    As well the block has a block guard so its been decked as well. Sounds kinda tight but I have no experience with how much clearance there is to begin with. Zealworks compression calculator says about 12.5:1.

    Thx for any input,
    Cheers.
     
  2. Briansol

    Briansol Admins Admin VIP

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  3. Tait72

    Tait72 Member

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    Thx for the reply, B.
     
  4. 78civic

    78civic Junior Member

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    If I remember right, there were dead-soft copper head gaskets that one could buy that had different thicknesses.
    Or Head-Savers would accompany the headgasket and 'build up' what was lost or machined away.

    Near the edges of the deck there are little flat 'dots' that I was told long ago that were there to measure the depth with, well.. A Depth gauge where the flat was on the deck and the gauge reached down to the 'dot'.

    If you look at yours and see that BOTH the deck and dot are ground/machined, well you may have a doorstop.

    I don't have any pics for you but, it's a little recessed area with a little nub/dot about 3/16dia. in the middle of that area.

    AND remember that for material machined off, it RETARDS the valve timing. And could even mess up the belt length.
    E
     
    Last edited: Jan 16, 2013
  5. Tait72

    Tait72 Member

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    So with Cometic making a headgaskets as thick as .040, I should have the necessary clearances.
     
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