Welcome to the North American Subaru Impreza Owners Club Saturday April 19, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 07-19-2006, 05:43 PM   #1
fenix281
Scooby Newbie
 
Member#: 98481
Join Date: Oct 2005
Location: CT
Vehicle:
2001 Impreza L
Green

Default RS Heads

I've heard that the rs heads from the 2001 2.5l will bolt on to the 2.2l. What I'm wondering is if its true and where I can find used heads for cheap. Any info would be appreciated.
* Registered users of the site do not see these ads.
fenix281 is offline   Reply With Quote
Old 07-19-2006, 09:52 PM   #2
Rally_wgn
Scooby Specialist
 
Member#: 62629
Join Date: May 2004
Chapter/Region: MAIC
Location: Richmond,VA
Vehicle:
1996 OBS in Green
2.5 N/A w/ full exhaust

Default

They will but compression is significantly lower so less power. If your looking to turbo this would be a good thing on the surface but I dont think either the block or the heads are capable of holding much boost.
Rally_wgn is offline   Reply With Quote
Old 07-20-2006, 11:38 PM   #3
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
QuickSilver Metallic

Default

By my calculations the CR would only be about 0.4 lower, which would impact power, but I'm not sure I'd call that "significantly lower". That's using numbers for a '97 EJ22, though, so I don't know how much different an '01 EJ22 may be (as far as head volume and piston volume goes). Using numbers from here - http://wac.addr.com/auto/obs/turbo/ejcalcs.html - I get 9.35:1 compression, compared to 9.7:1 stock for the '97 EJ22.

AFAIK the EJ25 heads flow way better than the EJ22 heads, so that should more than make up for the lower CR (I think).

Pat Olsen
'97 Legacy 2.5GT sedan
Patrick Olsen is offline   Reply With Quote
Old 07-20-2006, 11:41 PM   #4
Rally_wgn
Scooby Specialist
 
Member#: 62629
Join Date: May 2004
Chapter/Region: MAIC
Location: Richmond,VA
Vehicle:
1996 OBS in Green
2.5 N/A w/ full exhaust

Default

My response was based on answers to similar questions posted here, admittedly I never ran the number so...

Thanks for the more knowledgable information Patrick.
Rally_wgn is offline   Reply With Quote
Old 07-21-2006, 01:02 PM   #5
Matt Monson
Scooby Guru
 
Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
Vehicle:
99 2.5RS, '85 911
'73 914 and 2012 BRZ

Default

To get it right, one needs to be very specific about which Ej25 heads and which Ej22 heads they are using. Also, whether it is a phase I Ej22 or phase II Ej22 will matter as it will impact deck height. I think the mid 8's number that is so often thrown around is confusing as that is for SOHC Ej25 heads on a phase I Ej22 block. I am not going to bother to re-run the numbers as I trust Pat's math and tend to agree with his assessment of the impact. Though, with a stock cam, I think the gains will be marginal at best...
Matt Monson is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
2004 WRX head unit and 98 RS head unit with pocket Turbo_Twinky NWIC Private Classifieds 0 03-05-2010 07:26 PM
WTB: 00' RS Heads/Head - NY Trademark Private 'Wanted' Classifieds 0 07-03-2006 04:24 PM
22T running PII SOHC RS heads on stock RS ECU idea “what do you think” amorton Built Motor Discussion 21 06-05-2006 05:56 PM
RS Heads vs. WRX heads JDM_Scobaru Subaru Conversions 39 01-10-2005 02:36 AM
2004 WRX Heads vs. Phase II SOHC RS heads... latinskllz Factory 2.0L Turbo Powertrain 6 06-28-2004 12:28 PM


All times are GMT -4. The time now is 07:02 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.