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Old 01-07-2008, 10:26 PM   #1
keirnna
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Default EJ20K V4 STI heads + EJ257 US STI SB any issues?

Will my EJ20K V4 STI heads successfully bolt to a US STI EJ257 SB? What will the compression ratio be? I have been searching, but I haven't seen many people do this. Thanks in advance. Links and information would be wonderful.
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Old 01-07-2008, 10:32 PM   #2
keirnna
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1996 Subaru STI RA
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Found this info:

http://forums.nasioc.com/forums/show...ht=ej20k+heads

Looks like it will be good. If there is more information I would love to have it. Thanks!
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Old 01-16-2008, 03:38 AM   #3
Legacy_Turbo
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Heads will physically bolt on without issues. They are the same casting as EJ25 DOHC heads which are popular on hybrids. Also, heads are more like 49cc.

You`ve got yourself the best heads for a phase I engine.
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Old 01-16-2008, 12:22 PM   #4
Marnix
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With 0.58 mm gasket thickness (11044AA641) your CR will be 9.0.
With 1.37 mm gasket thickness (11044AA610) your CR will be 8.4.

That's based on 47cc for the EJ20K heads (clover-style combustion chamber).
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