Welcome to the North American Subaru Impreza Owners Club Tuesday December 12, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Subaru Conversions

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 05-26-2008, 11:33 PM   #1
mxpunk
Scooby Specialist
 
Member#: 132130
Join Date: Nov 2006
Chapter/Region: TXIC
Location: Austin, Texas
Vehicle:
2002 Ford F-150
Graphite Gray

Default CR for ej205 block w/ ej25d heads

wondering what the CR is for a usdm ej205 w/ 98 rs heads?
* Registered users of the site do not see these ads.
mxpunk is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 05-27-2008, 12:53 AM   #2
Jaxx
NASIOC Supporter
 
Member#: 177
Join Date: Aug 1999
Chapter/Region: NWIC
Location: Austin, Texas, USA
Vehicle:
The 93 W/EJ20K-sold
Subaru-less :(

Default

wouldn't the issue be the weird quench area ...
Jaxx is offline   Reply With Quote
Old 05-27-2008, 02:13 AM   #3
mxpunk
Scooby Specialist
 
Member#: 132130
Join Date: Nov 2006
Chapter/Region: TXIC
Location: Austin, Texas
Vehicle:
2002 Ford F-150
Graphite Gray

Default

Quote:
Originally Posted by Jaxx View Post
wouldn't the issue be the weird quench area ...

i thoguht this too unitl fuji K brought it to our attention that the combustion chamber is actually smaller on these heads then the ej205 heads..therefore enabling the rs heads to be implemented right/

im contemplating just picking up an ej205 SB and doing this instead of buying an ej22e and rebuilding it and using it with the ej25d heads..

i wanted to do the low compression build but i think id be happy with a decent 290-300 whp out of a smaller turbo then 350ish+ out of a big turbo + lots of lag

im looking for balance here, not a full top end drag motor for tons of boost
mxpunk is offline   Reply With Quote
Old 05-27-2008, 11:20 AM   #4
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

Put an Ej20 head gasket up against that head before you fully commit. I am sure that SOHC Ej25 heads won't make a seal. I suspect that Ej25d heads may be the same way. It's not about the size of the combustion chamber. It's about the bore of the mating surface.

Furthermore, what makes you think that an Ej205 block is any better than an Ej22e shortblock? I'd personally take the greater displacement. The strength of the internals are comparable and the compression ratio is just fine for boosting.
Matt Monson is offline   Reply With Quote
Old 05-27-2008, 06:51 PM   #5
mxpunk
Scooby Specialist
 
Member#: 132130
Join Date: Nov 2006
Chapter/Region: TXIC
Location: Austin, Texas
Vehicle:
2002 Ford F-150
Graphite Gray

Default

well, id rather get the 2.0 and be done with it then get an ej22 then have to tear it down
mxpunk is offline   Reply With Quote
Old 05-27-2008, 08:31 PM   #6
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

Then find a good used Ej22e bottom end with a known history. I'd personally trust it more than I would any take out Ej205 block. It's also likely to be cheaper. Hell, I'd take an Ej22e with unknown history and 150k mi and put it in and boost before I would put any unknown 50K mi Ej205 block in my car. Ej22 powered late 90's legacies see a lot less abuse than any WRX that I've ever seen.
Matt Monson is offline   Reply With Quote
Old 05-31-2008, 12:57 AM   #7
mxpunk
Scooby Specialist
 
Member#: 132130
Join Date: Nov 2006
Chapter/Region: TXIC
Location: Austin, Texas
Vehicle:
2002 Ford F-150
Graphite Gray

Default

Quote:
Originally Posted by Matt Monson View Post
Then find a good used Ej22e bottom end with a known history. I'd personally trust it more than I would any take out Ej205 block. It's also likely to be cheaper. Hell, I'd take an Ej22e with unknown history and 150k mi and put it in and boost before I would put any unknown 50K mi Ej205 block in my car. Ej22 powered late 90's legacies see a lot less abuse than any WRX that I've ever seen.

valid points for sure, the ej22e is a solid motor and im sure with t-leg pistons can support a good 350 whp or more.

sometimes i get cocky and think im gonna do this and rev the thing to 7.5K and put an td06-20G snail on it but then i realize a 1.8ECU plus piggyback wont be able to handle this
mxpunk is offline   Reply With Quote
Old 05-31-2008, 11:06 AM   #8
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

t-leg pistons aren't any better than na leg pistons. Same cast pistons just different compression ratio. If mating Ej25 heads to it, you actually want to keep the Ej22e na pistons. If you go with Ej22t pistons, you run a compression ratio in the low 7's. With the NA pistons and DOHC Ej25 heads you are at an almost perfect 8.6:1.

As far as 350whp? Hitting that is going to be all about the tune. As I kind of alluded to in my PM, you will want a standalone if that number is your real goal.
Matt Monson is offline   Reply With Quote
Old 06-06-2008, 01:19 AM   #9
mxpunk
Scooby Specialist
 
Member#: 132130
Join Date: Nov 2006
Chapter/Region: TXIC
Location: Austin, Texas
Vehicle:
2002 Ford F-150
Graphite Gray

Default

thanks matt, helpful as always
mxpunk 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
EJ205 Blocks,Heads, cams, EJ257 block, cams gotawd Engine/Power/Exhaust 22 04-30-2009 10:18 AM
ej25d heads with a ej205 shortblock blu subaru Built Motor Discussion 3 07-11-2008 02:20 AM
Torque specs for EJ205 block head bolts? ChrisRT Subaru Conversions 3 09-19-2007 06:52 PM
CR for V7 shortblock with EJ20 heads azulito Subaru Conversions 0 08-22-2005 11:28 PM
anyone know the CR for the 2.2L Turbo heads? Eric SS Normally Aspirated with bolt-on Forced Induction Powertrain 7 09-21-2001 10:24 PM

All times are GMT -4. The time now is 09:40 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.