Welcome to the North American Subaru Impreza Owners Club Thursday October 23, 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 > Pre-2002 Factory Turbo 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 04-23-2009, 02:38 PM   #1
sniper512
Scooby Newbie
 
Member#: 189923
Join Date: Sep 2008
Chapter/Region: W. Canada
Location: Cranbrook, BC
Vehicle:
1993 JDM WRX
Black

Default Early EJ20G heads with 2.5 STI Block?

I was just wondering if this is possible. I have a 93 JDM WRX. I am going with the STI 6MT as well. I wanna use my heads and everything else in the car except swap in a 2.5 block and 6MT for more power handling and reliability.

I will most likely be going standalone down the road.
* Registered users of the site do not see these ads.
sniper512 is offline   Reply With Quote
Old 04-23-2009, 04:03 PM   #2
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

Yep. It's been done a bunch of times. It's a bolt on affair. The only additional challenge is the extra crankcase breather and the coolant crossover pipe. But it's not a major issue.
Matt Monson is offline   Reply With Quote
Old 04-23-2009, 11:27 PM   #3
sniper512
Scooby Newbie
 
Member#: 189923
Join Date: Sep 2008
Chapter/Region: W. Canada
Location: Cranbrook, BC
Vehicle:
1993 JDM WRX
Black

Default

So basically a good catch can setup and a modified pipe. Hmm well I'll start looking. A stock short block seems fairly inexpensive. The tranny will be the biggest cost. At least with the sti block the 6MT will bolt up with all 8 bolts not 4 lol.

So the oil and coolant journals are the same between the 2.5 block and the older phase 1 ej20g's?
sniper512 is offline   Reply With Quote
Old 04-24-2009, 01:24 AM   #4
DSM_Outback
Scooby Specialist
 
Member#: 56345
Join Date: Mar 2004
Location: Western Colorado
Vehicle:
93 Swapped L
Green

Default

Yeah.
Beware if those are the rocker EJ20G heads, lifter suck and they make no power up top.
DSM_Outback is offline   Reply With Quote
Old 04-24-2009, 04:45 AM   #5
Marnix
Scooby Specialist
 
Member#: 51480
Join Date: Dec 2003
Chapter/Region: International
Location: The Netherlands
Vehicle:
1984 AM5, 1994 BC4,
2010 BR5

Default

In the first post it says 93 JDM WRX so it won't have the rocker heads.

Be aware that compression ratio will be as follows:

9.2:1 with 0.58mm original EJ257 gasket 11044AA641 (holes for intake manifold won't line up)
8.9:1 with 1.00mm Cometic gasket
8.6:1 with 1.37mm original EJ25D gasket 11044AA610
Marnix is offline   Reply With Quote
Old 04-24-2009, 10:41 AM   #6
sniper512
Scooby Newbie
 
Member#: 189923
Join Date: Sep 2008
Chapter/Region: W. Canada
Location: Cranbrook, BC
Vehicle:
1993 JDM WRX
Black

Default

So the EJ257 from the USDM STI isn't gonna work with my intake mani?

EJ25D what car has this motor and how much power is it able to hand roughly?
sniper512 is offline   Reply With Quote
Old 04-24-2009, 10:54 AM   #7
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

That's not what he's saying. The Ej257 will work, but you just want to use the Ej25D (dohc NA engine from 1996-1999) gasket. It's a phase I gasket and is thicker, which is what you want since you are using phase I heads. It's both the right compression ratio and the right manifold spacing. You just need the gasket, not the block.
Matt Monson is offline   Reply With Quote
Old 04-24-2009, 11:55 AM   #8
sniper512
Scooby Newbie
 
Member#: 189923
Join Date: Sep 2008
Chapter/Region: W. Canada
Location: Cranbrook, BC
Vehicle:
1993 JDM WRX
Black

Default

Haha oops ya that makes sense. Thanks for the help. I'll start sourcing parts for this. One other question though. Do you think the factory ECU will be happy with the extra displacement? I would imagine so. It would only be temporary till I got a standalone.
sniper512 is offline   Reply With Quote
Old 04-24-2009, 05:39 PM   #9
DSM_Outback
Scooby Specialist
 
Member#: 56345
Join Date: Mar 2004
Location: Western Colorado
Vehicle:
93 Swapped L
Green

Default

Quote:
Originally Posted by Matt Monson View Post
That's not what he's saying. The Ej257 will work, but you just want to use the Ej25D (dohc NA engine from 1996-1999) gasket. It's a phase I gasket and is thicker, which is what you want since you are using phase I heads. It's both the right compression ratio and the right manifold spacing. You just need the gasket, not the block.
I have used the 257 HG on a EJ257/EJ25D build, intake manifold fit/lined up fine.
DSM_Outback is offline   Reply With Quote
Old 04-24-2009, 06:47 PM   #10
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

Quote:
Originally Posted by DSM_Outback View Post
I have used the 257 HG on a EJ257/EJ25D build, intake manifold fit/lined up fine.
Talk to Marnix about it. I wasn't the one making the claim. I just re-explained to the OP what Marnix was telling him to do. I've never built this particular motor.
Matt Monson is offline   Reply With Quote
Old 04-24-2009, 07:06 PM   #11
suberdave
NASIOC Supporter
 
Member#: 101865
Join Date: Nov 2005
Chapter/Region: NWIC
Location: Covington, WA
Vehicle:
88 GL-10 STi
silver

Default

Quote:
Originally Posted by sniper512 View Post
Do you think the factory ECU will be happy with the extra displacement? I would imagine so. It would only be temporary till I got a standalone.
Thats a big fat NO. you are looking at 25% more displacememt. you will need a way of tuneing and you will need much larger injectors.

i spent my money on EM first. now i can do anything i want, and be able to tune for it...

-=Suberdave=-
suberdave is offline   Reply With Quote
Old 04-24-2009, 07:20 PM   #12
LateGc8
Scooby Newbie
 
Member#: 204564
Join Date: Mar 2009
Chapter/Region: SCIC
Location: Orange county
Vehicle:
98 gc8
grey

Default

+1 for suberdave!
LateGc8 is offline   Reply With Quote
Old 04-24-2009, 08:34 PM   #13
sniper512
Scooby Newbie
 
Member#: 189923
Join Date: Sep 2008
Chapter/Region: W. Canada
Location: Cranbrook, BC
Vehicle:
1993 JDM WRX
Black

Default

That's what I will do. I am just going to start finding what I need for next winter no big rush. For this summer I'll be happy with 250whp+ i suppose lol. Next year I'll build her up when my shop isn't so busy.
sniper512 is offline   Reply With Quote
Old 04-25-2009, 01:46 AM   #14
Marnix
Scooby Specialist
 
Member#: 51480
Join Date: Dec 2003
Chapter/Region: International
Location: The Netherlands
Vehicle:
1984 AM5, 1994 BC4,
2010 BR5

Default

Quote:
Originally Posted by DSM_Outback View Post
I have used the 257 HG on a EJ257/EJ25D build, intake manifold fit/lined up fine.
The block will be roughly 2 mm less wide with the thin gaskets therefore the manifold won't line up. You can drill out the holes in the manifold though to make it work but why would you want to do so if you end up with a too high CR anyway? Besides, the ports of manifold to head will also be off (by 1mm per side).

Besides those issues you will also have to use the latest belt tensioner setup with the extra idler when using the thin gaskets to prevent belt slack. With the thicker gaskets you can use your original setup.

As for the EM: I agree with Dave, fully. However, you can use the original ECU temporarily but you will have to run waste gate pressure (ca. 0.4-0.5 bar) only to prevent the issues described.
Marnix is offline   Reply With Quote
Old 04-25-2009, 01:56 AM   #15
sniper512
Scooby Newbie
 
Member#: 189923
Join Date: Sep 2008
Chapter/Region: W. Canada
Location: Cranbrook, BC
Vehicle:
1993 JDM WRX
Black

Default

Awesome thanks for all your guys help.
sniper512 is offline   Reply With Quote
Old 04-27-2009, 01:01 AM   #16
DSM_Outback
Scooby Specialist
 
Member#: 56345
Join Date: Mar 2004
Location: Western Colorado
Vehicle:
93 Swapped L
Green

Default

Quote:
Originally Posted by Marnix View Post
The block will be roughly 2 mm less wide with the thin gaskets therefore the manifold won't line up. You can drill out the holes in the manifold though to make it work but why would you want to do so if you end up with a too high CR anyway? Besides, the ports of manifold to head will also be off (by 1mm per side).

Besides those issues you will also have to use the latest belt tensioner setup with the extra idler when using the thin gaskets to prevent belt slack. With the thicker gaskets you can use your original setup.
I agree on the tensioner setup but continue to disagree with you about the manifold geometry.
This build I did was for a US 98 Legacy GT, it had an EJ25D in it. We ditched the shortblock for an EJ257, I rebuilt the heads and we used EJ257 OEM STI headgaskets and I 5hit you not, intake manifold installation was smooth. No hogging holes out or drill bit wiggling was required. True story.
DSM_Outback is offline   Reply With Quote
Old 04-27-2009, 10:08 PM   #17
elislider
Scooby Specialist
 
Member#: 133923
Join Date: Dec 2006
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
03 Legacy GT wagon
I love goooollllllllddddd

Default

Quote:
Originally Posted by Marnix View Post
In the first post it says 93 JDM WRX so it won't have the rocker heads.

Be aware that compression ratio will be as follows:

9.2:1 with 0.58mm original EJ257 gasket 11044AA641 (holes for intake manifold won't line up)
8.9:1 with 1.00mm Cometic gasket
8.6:1 with 1.37mm original EJ25D gasket 11044AA610
what would be ideal. im thinking about ditching my ej20k shortblock for a 257 as well
elislider is offline   Reply With Quote
Old 04-28-2009, 12:17 AM   #18
ballitch
Scooby Specialist
 
Member#: 74907
Join Date: Nov 2004
Chapter/Region: NWIC
Location: salem, OR
Vehicle:
98 cam'd EJ251
Wrx Tranny,slowr than ish

Default

Quote:
Originally Posted by Marnix View Post


9.2:1 with 0.58mm original EJ257 gasket 11044AA641 (holes for intake manifold won't line up)
8.9:1 with 1.00mm Cometic gasket
8.6:1 with 1.52mm original EJ25D gasket 11044AA610
Take that into account.


~Josh~
ballitch is offline   Reply With Quote
Old 04-28-2009, 12:17 AM   #19
DSM_Outback
Scooby Specialist
 
Member#: 56345
Join Date: Mar 2004
Location: Western Colorado
Vehicle:
93 Swapped L
Green

Default

Below 9:1 on pump gas, on E85 the higher the better IMO.
DSM_Outback is offline   Reply With Quote
Old 05-07-2009, 07:10 PM   #20
Eatoniashoprat
Scooby Newbie
 
Member#: 143416
Join Date: Mar 2007
Chapter/Region: W. Canada
Location: Saskatoon
Vehicle:
1971 Super Beetle
EJ20g Platinum Grey

Default

Quote:
Originally Posted by Marnix View Post

Besides those issues you will also have to use the latest belt tensioner setup with the extra idler when using the thin gaskets to prevent belt slack. With the thicker gaskets you can use your original setup.
Marnix which one is the latest? The one piece with one bolt and the whole thing pivots or the two bolt holding the cylinder and seperate pivoting pulley? Is this a straight forward bolt on affair to switch between both? I've had both apart but can't remember.
Eatoniashoprat is offline   Reply With Quote
Old 05-07-2009, 10:37 PM   #21
DSM_Outback
Scooby Specialist
 
Member#: 56345
Join Date: Mar 2004
Location: Western Colorado
Vehicle:
93 Swapped L
Green

Default

One bolt is the newest and you'd need the mounting bracket as well.
DSM_Outback is offline   Reply With Quote
Old 05-09-2009, 03:40 PM   #22
Eatoniashoprat
Scooby Newbie
 
Member#: 143416
Join Date: Mar 2007
Chapter/Region: W. Canada
Location: Saskatoon
Vehicle:
1971 Super Beetle
EJ20g Platinum Grey

Default

Well, since it looks like the original poster had his questions answer I'm going to take over, lol. I'm trying to cost out doing this swap and figuring out everything that is needed to make this go smoothly (if anyone does this in the future). If I do go ahead with this swap I'll update with any additional things I run into. Here are two other threads discussion this: STI Block EJ20G heads? and Ej20g + Ej257 = ?

My car has 550cc injectors, TD05-16g and using Apexi PFC for tune. I'm looking for around 350 hp atc. I imagine I'll be upgraded the MAF to a Z32 or Q45. If anyone can add to this list with numbers and any other parts needed I will update it with your posts to help make this an easy conversion for those in the future.

New parts needed

-Ej257 short block - 10103AB440
-Ej257 oil pump - 15010AA280
-Ej257 water pump - 21111AA240
-EJ257 timing belt - 13028AA240 if switching to new style tensioner
-EJ257 tensioner, mounting plate and extra idler -
I've also read that you can use the old style tensioner but not sure which belt you'd use then?
-Head gasket -
if early legacy heads use EJ257 - 11044AA641
if wrx heads use EJ25D - 11044AA610
-Head bolts
-Gasket kit - not sure whats all included - intake mani, exh,?


Also I would change (part numbers needed, not sure in differences between wrx and legacy heads here)

-EJ20g cam seals - 806732150
-Ej20g Valve Cover seals - are these needed or can they be cleaned and work like new?

Last edited by Eatoniashoprat; 05-10-2009 at 09:11 AM.
Eatoniashoprat is offline   Reply With Quote
Old 05-09-2009, 05:55 PM   #23
m0nkeyballz
Scooby Newbie
 
Member#: 198411
Join Date: Dec 2008
Chapter/Region: SCIC
Location: Long Beach California!
Vehicle:
2001 Subaru RSTI
APEX SILVER

Default

Sorry to hijack but since were on the discussion of headgaskets to use with different block/heads. I am doing an ej25d block with ej18 heads from my 93 L. I was told that it will be a bolt on affair also. But I am curious as to what headgaskets to use? I think ej257 gaskets would be best. But I also want to raise the compression as this will be an all motor build. Cometic? Help me please.
m0nkeyballz is offline   Reply With Quote
Old 05-09-2009, 07:12 PM   #24
Eatoniashoprat
Scooby Newbie
 
Member#: 143416
Join Date: Mar 2007
Chapter/Region: W. Canada
Location: Saskatoon
Vehicle:
1971 Super Beetle
EJ20g Platinum Grey

Default

Quote:
Originally Posted by m0nkeyballz View Post
Sorry to hijack but since were on the discussion of headgaskets to use with different block/heads. I am doing an ej25d block with ej18 heads from my 93 L. I was told that it will be a bolt on affair also. But I am curious as to what headgaskets to use? I think ej257 gaskets would be best. But I also want to raise the compression as this will be an all motor build. Cometic? Help me please.
How dare you hijack my hijacked thread, lol! I don't know the answer sorry but for something as different as that I would almost start your own thread at least for the reason that it would be easier for people to find if searching for that in the future, IMO.
Eatoniashoprat is offline   Reply With Quote
Old 05-09-2009, 08:32 PM   #25
m0nkeyballz
Scooby Newbie
 
Member#: 198411
Join Date: Dec 2008
Chapter/Region: SCIC
Location: Long Beach California!
Vehicle:
2001 Subaru RSTI
APEX SILVER

Default

Very true man, thanks. Good luck with your build.
m0nkeyballz 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
Upgraded 2.0 heads with 2.5 block MS WRX Built Motor Discussion 3 01-11-2008 08:21 PM
WRX with 2.5 Sti Block 293whp 13.5k! awdvf22 Private Vehicle 'For Sale' Classifieds 5 03-21-2007 03:19 PM
WRX with 2.5 Sti Block 293whp awdvf22 Private Vehicle 'For Sale' Classifieds 4 03-17-2007 05:12 PM
help with 2.5 sti block breather holes plugged? ktmbass85 Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 7 03-07-2006 04:37 PM
2.5 sti block with 2.0 regular wrx heads serious Normally Aspirated with bolt-on Forced Induction Powertrain 21 08-03-2003 12:36 PM


All times are GMT -4. The time now is 12:45 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.