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Old 08-28-2005, 11:13 PM   #1
jdb2300
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Default Heads on a ej25

Does anyone know anything about which heads you can put on the ej25 dual overhead. And what would the pro's and con's of doing it?
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Old 08-28-2005, 11:18 PM   #2
Patrick L
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Say what?
which heads can you put on a ej25 dual overhead?
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Old 08-29-2005, 12:29 AM   #3
The Stig
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I believe he wants to know which heads will work on the DOHC version of the EJ25 and what would be the pros and cons of each head. Off the top of my head (no pun intended), the SOHC ej25 head should work, the ej20 wrx head should work, and the STi head. The latter two will probably cost you a pretty penny. I remember seeing a thread somewhere measuring the different CRs on a EJ25 using different heads. Using the EJ20 or the STi head should improve air flow, but likely you'll need other mods to take advantage of it.
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Old 08-29-2005, 01:22 AM   #4
poormansporsche
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Your heads flow pretty well. Pretty much every 2.5RS has pretty good heads. I think switching to WRX or STI heads might be advantagous in that they have AVCS but really would be more of a pain than anything else. I dunno who you're going to find to tune a mutha like that.

cheers

garrett
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Old 08-29-2005, 09:28 PM   #5
jdb2300
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I think I read recently that the 2.2 heads would work. Is this true?
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Old 08-30-2005, 11:52 AM   #6
Matt Monson
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Quote:
Originally Posted by The Stig
I believe he wants to know which heads will work on the DOHC version of the EJ25 and what would be the pros and cons of each head. Off the top of my head (no pun intended), the SOHC ej25 head should work, the ej20 wrx head should work, and the STi head. The latter two will probably cost you a pretty penny. I remember seeing a thread somewhere measuring the different CRs on a EJ25 using different heads. Using the EJ20 or the STi head should improve air flow, but likely you'll need other mods to take advantage of it.
BZZZZT! Wrong answer. Both the Ej25 heads in SOHC and DOHC versions outflow the USDM Ej205 heads. And you cannot put Ej257 STi heads in without coverting absolutely everything. How do you plan on making the AVCS work on a stock ECU?

kbd2300,
Yes, you can put your Ej22 heads on an EJ25 bottom end, and get a nice compression and displacement bump. Do a search in this forum. Use "frankenstein" as your key word and search titles. You'll get the info you are looking for...
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Old 08-30-2005, 07:19 PM   #7
jdb2300
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Thank you i was hoping that the 2.2 heads on the 2.5 engine would create more power.
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