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Old 05-23-2007, 04:26 PM   #1
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Default How much can you bore?

How much can you bore out a SI? I'm thinking about what to do with my old engine.
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Old 05-23-2007, 04:32 PM   #2
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didn't Sqela do this to his when he rebuilt it because he scratched the walls...

i think he knows.
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Old 05-23-2007, 04:34 PM   #3
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It will depend on the amount of core shift but on the series II motors we typcially see anythign beyond .030 as being dangerious however we have gone as far as .060 on a motor and it was sonic tested good.
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Old 05-23-2007, 04:40 PM   #4
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What does dangerous mean?
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Old 05-23-2007, 04:43 PM   #5
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It means the cylinder walls are too thin to handle the load imposed by the compression and explosion of the charge. As well heat is a large contender.
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Old 05-23-2007, 04:49 PM   #6
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So it will deform or blowout?
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Old 05-23-2007, 06:26 PM   #7
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try it with your luck... What do you have to lose... lmao
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Old 05-23-2007, 06:43 PM   #8
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It would most likely distort and have excessive blow by.

In an extreme case I guess you could get cracking in the cylinder wall.
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Old 05-23-2007, 10:46 PM   #9
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Quote:
Originally Posted by Rogue
It will depend on the amount of core shift but on the series II motors we typcially see anythign beyond .030 as being dangerious however we have gone as far as .060 on a motor and it was sonic tested good.
stick to .020 on the series I

when I first was planning the rebuild I was aiming for .030 but was advised to stay to .020 by my machinist who has been doing engine blocks for over 30 years
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Old 05-23-2007, 11:39 PM   #10
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i did 30 over on mine and haven't had a problem
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