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Old Jul 23, 2009 | 12:16 PM
  #61  
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https://www.miataturbo.net/forum/t37356/#post433338
look again at post, not sure if the price chages, but it shouldnt
Old Jul 23, 2009 | 12:45 PM
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Originally Posted by djp0623
I believe the site lists the 9.0:1 for the 85.5mm. I'm not overboring that much
The vendor may not have them all listed, but according to the supertech catalog, 9.0:1 is available in 84mm, 85mm, and 85.5mm.

Are you running turbo or N/A? For a non-turbo motor seeing track use, go for the high-comp units. For a turbo motor, go for the lowest CR you can get. The actual difference between an 8.6:1 and a 9:1 is going to be pretty trivial both in and out of boost, but it never hurts to have that little extra margin of safety.
Old Jul 23, 2009 | 03:51 PM
  #63  
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Joe..are you going for 1.8L ? I think I will ditch my 1.6L setup and get a 1.8L once for all.
Old Jul 23, 2009 | 04:52 PM
  #64  
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Originally Posted by Savington
I wouldn't blame that on the Weiscos. If he's been through multiple motors, he needs to find a new builder. Damage on the skirts like that suggests that the builder just fucked up his clearances. You have to look at any secondary failures, like the coating chipping away, as a possible result of the primary failure.

BTW - Supertech recommends some insanely low clearances, like .0027". I built my motor much looser than that, the .006" range, after talking with the machinist who did the bore/hone on the block about what it was going to be used for.



Look familiar? My Weiscos after 2-3K. Hard to tell in the pic, but look ALOT like the above picture.

Sav., I am probably getting the Supertechs, and also do track days. Not a ton, but a few. Car will also be started on some extreme cold days. Would you suggest that kind of clearance?
Old Jul 23, 2009 | 07:35 PM
  #65  
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Originally Posted by aznDragonX
Joe..are you going for 1.8L ?
Yeah, I decided that my plans for the motor will ultimately require a new manifold and turbo anyway, so if I can score a '99+ (or even '96+) motor I can take advantage of the factory crank trigger setup.

I'm dying a thousand deaths waiting for Lev to get back from the gap so I can find out if I can grab the whole drivetrain out of the 99AE that he just scored and is parting. He's close enough that I can drive out and haul it back.
Old Jul 23, 2009 | 11:34 PM
  #66  
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Originally Posted by Joe Perez
The vendor may not have them all listed, but according to the supertech catalog, 9.0:1 is available in 84mm, 85mm, and 85.5mm.
Indeed they do. That is what I have in my car.
Old Jul 24, 2009 | 12:38 AM
  #67  
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Originally Posted by SpyHunter
Would you suggest that kind of clearance?
Clearance is a discussion best left to machinists and builders. I can only share what I did - my clearances (IIRC) are in the .006" range. My motor also has maybe 75 miles on it, tops.
Old Jul 24, 2009 | 11:10 AM
  #68  
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What do the piston manufacturers say?
Old Jul 24, 2009 | 11:11 AM
  #69  
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Are these problematic Wisecos from FM? I though FM had some exclusive special Wisecos?
Old Jul 24, 2009 | 11:49 AM
  #70  
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Difference between FM Weisco and Weisco:

Turbo Pistons - MX-5 Miata Forum
Old Jul 24, 2009 | 12:07 PM
  #71  
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Since they're so close, it seems like you would almost want to make a decision based on which design looks more resistant to forming hot spots. If one piston has less edges or softer edges on the top of the piston I would make that my deciding factor.
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