What size pistons are you using?

What size piston are you using?

  • 83mm

    Votes: 11 26.8%
  • 83.5mm

    Votes: 18 43.9%
  • 84mm

    Votes: 10 24.4%
  • 84.5mm

    Votes: 1 2.4%
  • 85mm

    Votes: 0 0.0%
  • 85.5mm

    Votes: 0 0.0%
  • 86mm

    Votes: 1 2.4%

  • Total voters
    41

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
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I come from a land down under
Casey: Can't pin it down exactly but NA's got them long before 89 and GTE's seem to be as Dow said sometime in late 89.

They're +2mm just about everywhere so are a huge improvement and I suspect were an answer to the Deck Cracking issues!
 

whudafux

Formerly dcrusupra
Jan 5, 2006
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Cullowhee, NC
www.myspace.com
IJ. said:
Casey: Can't pin it down exactly but NA's got them long before 89 and GTE's seem to be as Dow said sometime in late 89.

They're +2mm just about everywhere so are a huge improvement and I suspect were an answer to the Deck Cracking issues!

DAMMIT! Toyota has screwed me again! :rant2: Guess I'll have to be extra careful with the build. Maybe I'll just go back to N/A. Lol
 

tig321

New Member
Mar 13, 2006
151
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Edmonton/Victoria
IJ. said:
Tig: Thanks!

Late model "Heavy Casting" top early model "Light Casting" lower







Oh, I see!
I didn't realize there was such a difference between the model years.

Doward said:
tig321 - due to the fact that you have to have some clearance for the piston, you can actually have the head gasket bore the exact size as your cylinder bore - this is optimal for a number of reasons :)

Thats good, I would like to keep as much of the gas in the quench area as possible. I hope SCE goes ahead with this.:x:
 
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Doward

Banned
Jan 11, 2006
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Alachua, FL
I know, I REALLY can't stand that about the HKS gasket. Call me picky, but it could very well be the difference in daily driven reliability, or race only (and hence, the need to tear down often)

IJ, I'm shooting you a PM about something I spoke with the techs over @ Total Seal about...
 

bigaaron

Supramania Contributor
Apr 12, 2005
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Pomona, CA
www.driftmotion.com
We've built many 7m engines and all but one used a HKS headgasket with a 86mm bore. The other one was a Greddy which is almost identical to the HKS. We have had no issues whatsoever.

I was going to go with 85mm bore pistons for my personal engine this time, but I think I'm going to stick with 84mm for the sake of longevity.