Welcome to the North American Subaru Impreza Owners Club Tuesday March 19, 2024
Home Forums Images 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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 03-17-2013, 06:04 PM   #1
morrocco88
Scooby Specialist
 
Member#: 104098
Join Date: Jan 2006
Chapter/Region: NWIC
Location: Eastern WA
Vehicle:
97' LGT 2.3 Dstroke
Rotated BW S256 6speed

Default 07'-09' Legacy shortblock with phase I 2.5 DOHC Heads

I've searched a bunch and no specific help.

I have a 07'-09' phase II N/A short block with low low miles and want to put some 97' legacy DOHC heads on it. The thing I'm unsure of is if the pistons will work with those combustion chambers, as they pop up out of the block a little. I'm not worried about the compression too much, but rather if it will interfere or not.

Anybody been down this trail before?

Thanks!
morrocco88 is offline   Reply With Quote
Old 03-24-2013, 07:14 AM   #2
JoshP
Scooby Specialist
 
Member#: 94350
Join Date: Aug 2005
Chapter/Region: NESIC
Location: S. Maine
Default

Are the pistons domed? If so, then no they wont work. You can swap in P1 pistons and that will work.
JoshP is offline   Reply With Quote
Old 03-24-2013, 08:35 AM   #3
Patrick Olsen
Scooby Guru
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
1996 Impreza coupe

Default

The EJ25D pistons also protruded from the deck, too, but only by 0.05mm (which was less than the head gasket thickness by quite a bit).

How does the '07-09 compare to that?
Patrick Olsen is offline   Reply With Quote
Old 03-25-2013, 02:00 PM   #4
morrocco88
Scooby Specialist
 
Member#: 104098
Join Date: Jan 2006
Chapter/Region: NWIC
Location: Eastern WA
Vehicle:
97' LGT 2.3 Dstroke
Rotated BW S256 6speed

Default

They seem to pop out past the Deck quite a ways. I've been told by another source that it will not work.

I just picked up a 99' Forester with a phase II EJ25 (spun bearing) with 53K original miles. If the heads look good, I might just use it for that....asuming it will work with those heads?
morrocco88 is offline   Reply With Quote
Old 03-25-2013, 02:47 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

They'll hit. The newer 2.5i pistons are way too domed.
Matt Monson is offline   Reply With Quote
Old 03-25-2013, 10:32 PM   #6
morrocco88
Scooby Specialist
 
Member#: 104098
Join Date: Jan 2006
Chapter/Region: NWIC
Location: Eastern WA
Vehicle:
97' LGT 2.3 Dstroke
Rotated BW S256 6speed

Default

Do you think it will work on a 99' forester with the first of the phaseII motors?
morrocco88 is offline   Reply With Quote
Old 03-26-2013, 12:42 PM   #7
Patrick Olsen
Scooby Guru
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
1996 Impreza coupe

Default

Yes. There are plenty of examples of folks using the DOHC heads on the '99-05(ish) Phase II blocks, myself included.
Patrick Olsen is offline   Reply With Quote
Old 04-21-2013, 12:33 PM   #8
JoshP
Scooby Specialist
 
Member#: 94350
Join Date: Aug 2005
Chapter/Region: NESIC
Location: S. Maine
Default

Pat, the pistons dont protude, they are domed and the combustion chamber has a different shape. His '07 shortblock wont work with either set of heads he mentioned. Id be careful just throwing out incorrect info like that...

Heres a pic

JoshP is offline   Reply With Quote
Old 04-21-2013, 05:23 PM   #9
Patrick Olsen
Scooby Guru
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
1996 Impreza coupe

Default

Quote:
Originally Posted by JoshP View Post
Pat, the pistons don[']t prot[r]ude, they are domed and the combustion chamber has a different shape.
When you say "the pistons", I don't know which ones you're referring to since there have been 3 different short block varieties mentioned in this thread. The OP said the '07-09 pistons protruded from the deck; if you disagree with that information, then correct him. The only statement I made was about the EJ25D pistons, which do protrude 0.05mm from the deck. You can find that information in a variety of places on this forum. The math (courtesy of TWE): 30.3mm piston compression height + 131.25mm rod length + 1/2 the stroke = 201.05mm. Deck height is 201mm.

Quote:
Originally Posted by JoshP View Post
His '07 shortblock won[']t work with either set of heads he mentioned.
I never said it would. I did say that Phase I DOHC heads will work on an early Phase II block, since the OP asked about using the heads on a '99 Forester short block. Subaru built engines like that in '98 and '99, and I and a number of others have built engines like that.

Quote:
Originally Posted by JoshP View Post
I[']d be careful just throwing out incorrect info like that...
If you can point out what I said was incorrect, that would be great.
Patrick Olsen is offline   Reply With Quote
Old 04-21-2013, 06:57 PM   #10
JoshP
Scooby Specialist
 
Member#: 94350
Join Date: Aug 2005
Chapter/Region: NESIC
Location: S. Maine
Default

Quote:
Originally Posted by Patrick Olsen View Post
When you say "the pistons", I don't know which ones you're referring to since there have been 3 different short block varieties mentioned in this thread. The OP said the '07-09 pistons protruded from the deck; if you disagree with that information, then correct him. The only statement I made was about the EJ25D pistons, which do protrude 0.05mm from the deck. You can find that information in a variety of places on this forum. The math (courtesy of TWE): 30.3mm piston compression height + 131.25mm rod length + 1/2 the stroke = 201.05mm. Deck height is 201mm.


I never said it would. I did say that Phase I DOHC heads will work on an early Phase II block, since the OP asked about using the heads on a '99 Forester short block. Subaru built engines like that in '98 and '99, and I and a number of others have built engines like that.


If you can point out what I said was incorrect, that would be great.

a '99 shortblock was never mentioned, only shortblock he ever asked about was the '07. He clearly mentioned that his '99 Forester has a spun bearing... You obviously misread into that post.
JoshP is offline   Reply With Quote
Old 04-23-2013, 09:01 PM   #11
morrocco88
Scooby Specialist
 
Member#: 104098
Join Date: Jan 2006
Chapter/Region: NWIC
Location: Eastern WA
Vehicle:
97' LGT 2.3 Dstroke
Rotated BW S256 6speed

Default

So the 07' shortblock won't work with the 99' Forester heads either? I'm just about to tear into this project and hoped the 07' block would make it duck soup.
morrocco88 is offline   Reply With Quote
Old 04-21-2013, 06:24 PM   #12
FuJi K
Scooby Guru
 
Member#: 3687
Join Date: Jan 2001
Chapter/Region: MWSOC
Location: St. Paul, MN
Vehicle:
MY99 GF4 JDM 6spd
NF Performance

Default

Let me at those newer pistons with my porting bit. I'll make it work!
FuJi K 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

All times are GMT -4. The time now is 01:53 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.