Any Issue Rebuilding With an '04 STi Crank & Rods in an '04 WRX? - Subaru WRX Forum
 9Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 Old 02-20-2014, 01:37 PM Thread Starter
WRXtuners Member
 
LW_Black4's Avatar
 
Join Date: Mar 2013
Location: Ontario, Canada
Posts: 494
Images: 7
LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful
Garage
Any Issue Rebuilding With an '04 STi Crank & Rods in an '04 WRX?

Since I have access to these parts and the longer stroke would make it a EJ 2.2L build.

I'm hoping the modest additional displacement won't constrain cylinder head breathing or require fuel system upgrades at Stage 2 power levels. However, replacing the fuel pump and filter on a 10 year old engine at rebuild time is still a wise precaution.

Do you know of any issue rebuilding my EJ205 with a '04 STi crank & rods?
Attached Images
 

Laszlo - blue '04 WRX
Meet the turbocharged rally-bred Subaru WRX.
blue '09 STi - lease return
LW_Black4 is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 02-20-2014, 01:46 PM
WRXtuners Member
 
psinuse's Avatar
 
Join Date: Nov 2004
Location: Ohio
Posts: 3,094
psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to
Well you'll need fuel injectors, fuel pump, tune, better plugs(use a step colder I believe) and a few other little misc. things(pistons will have to be aftermarket)

Resident Grumpy Old Man(Keith)
03 SRP 2.34L
08' LGT Gears...
psinuse is offline  
post #3 of 18 Old 02-20-2014, 04:18 PM
Moderator
 
mosc's Avatar
 
Join Date: Mar 2005
Location: Pennsylvania
Posts: 6,499
Images: 7
mosc is a helpful contributing member
Garage
I dunno where you'd find pistons for those dimensions. Stock ones won't work. Keith, can you spec a piston like that?

04 STi 16G powered lagless fun
04 WRX: SOLD
mosc is offline  
post #4 of 18 Old 02-20-2014, 05:54 PM Thread Starter
WRXtuners Member
 
LW_Black4's Avatar
 
Join Date: Mar 2013
Location: Ontario, Canada
Posts: 494
Images: 7
LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful
Garage
Sounds like custom pistons are required, with a 2mm higher wrist pin placement.

Manley Pistons Subaru Impreza WRX EJ205 79mm Stroker Crank 92.5mm 8.5:1
Manley Pistons Subaru Impreza WRX EJ205 79mm Stroker Crank 92 5mm 8 5 1 | eBay

Laszlo - blue '04 WRX
Meet the turbocharged rally-bred Subaru WRX.
blue '09 STi - lease return
LW_Black4 is offline  
post #5 of 18 Old 02-20-2014, 06:42 PM
WRXtuners Member
 
psinuse's Avatar
 
Join Date: Nov 2004
Location: Ohio
Posts: 3,094
psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to
Quote:
Originally Posted by mosc View Post
I dunno where you'd find pistons for those dimensions. Stock ones won't work. Keith, can you spec a piston like that?
Manley makes an OTS piston for the application as well as a couple others.

Quote:
Originally Posted by LW_Black4
I was hoping the OEM fitment had that kind of contingency capacity for 200 cc more of displacement?

Fuel system upgrades have to be considered as well then, but I do like STi Pink injectors.
I highly, highly recommend a fuel upgrade, even the stock 2L on a Stg.2 can out flow the injectors. Pinks would work along with an upgraded fuel pump.
turmic likes this.

Resident Grumpy Old Man(Keith)
03 SRP 2.34L
08' LGT Gears...
psinuse is offline  
post #6 of 18 Old 02-20-2014, 06:44 PM
Moderator
 
mosc's Avatar
 
Join Date: Mar 2005
Location: Pennsylvania
Posts: 6,499
Images: 7
mosc is a helpful contributing member
Garage
That's amazing that there is enough demand that they have off the shelf pistons for an EJ205 with that crank ready for purchase. I guess you're not the only crazy guy out there!
psinuse, turmic and LW_Black4 like this.

04 STi 16G powered lagless fun
04 WRX: SOLD
mosc is offline  
post #7 of 18 Old 02-20-2014, 06:47 PM
WRXtuners Member
 
psinuse's Avatar
 
Join Date: Nov 2004
Location: Ohio
Posts: 3,094
psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to
This type of stroker motor has been out for a few years now and I believe even CP makes them. Biggest issue is the phantom knock tuners get with them. I know there is a plug that help resolve it, but for the life of me I can't think of it's name. MPS makes 2mm longer rods and sells them as a kit for stock 2L motor. Rods and pistons...seems kind of pointless unless you're wanting to make butt loads of power.
LW_Black4 likes this.

Resident Grumpy Old Man(Keith)
03 SRP 2.34L
08' LGT Gears...
psinuse is offline  
post #8 of 18 Old 02-20-2014, 07:05 PM
WRXtuners Member
 
arcticscythe's Avatar
 
Join Date: Dec 2013
Location: California
Posts: 439
arcticscythe is known to be trustworthy and helpful arcticscythe is known to be trustworthy and helpful
Garage
Definitely grab a new pump and fresh injectors. You'll definitely need them for the new build spec but they are 10 years old, old/dirty injectors make it harder to tune and a less than stellar fuel pump wont be able to keep up. I did some work on a bored/sleeved 2.2l with the supporting mods everyones talking about back in high school but it always seemed to run funny. It drank oil like no-bodys business.

Your venturing into unknown territory, now is a good time to talk to your tuner and see if they have tuned anything like that. Its not quite as simple as adding 10% across the board to your stage 2 tune. at this point its a custom build and it deserves a custom tune.

Jason
13 WRX Hatch - Cobb OTS Stage 1
arcticscythe is offline  
post #9 of 18 Old 02-20-2014, 08:27 PM Thread Starter
WRXtuners Member
 
LW_Black4's Avatar
 
Join Date: Mar 2013
Location: Ontario, Canada
Posts: 494
Images: 7
LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful
Garage
Quote:
Originally Posted by psinuse View Post
Rods and pistons...seems kind of pointless unless you're wanting to make butt loads of power.
I like that you get STi crank and rod strength and durability for a WRX EJ205 with the swap. However depending on the cost of the collateral upgrades required, it might not be the best value even if you can get the crank and rods cheap.

Pistons would be replaced in a rebuild anyway, so that's not an additional cost.

Laszlo - blue '04 WRX
Meet the turbocharged rally-bred Subaru WRX.
blue '09 STi - lease return
LW_Black4 is offline  
post #10 of 18 Old 02-21-2014, 12:51 PM Thread Starter
WRXtuners Member
 
LW_Black4's Avatar
 
Join Date: Mar 2013
Location: Ontario, Canada
Posts: 494
Images: 7
LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful
Garage
I might be able to get the '04 STi injectors (520 cc) and fuel pump (145 lph) as well. Photos below. This would be great!

And if it all works out, I'd drill out the stakes in the TGV valves and remove the butterfly plates at rebuild time.

After that it'd get a custom tune and ultimately a turbo back exhaust.
Attached Images
   

Laszlo - blue '04 WRX
Meet the turbocharged rally-bred Subaru WRX.
blue '09 STi - lease return
LW_Black4 is offline  
post #11 of 18 Old 02-21-2014, 02:09 PM
Moderator
 
mosc's Avatar
 
Join Date: Mar 2005
Location: Pennsylvania
Posts: 6,499
Images: 7
mosc is a helpful contributing member
Garage
If you have the stock STi injectors out, pay to get em modded. Will save you money in the long run. Mine made it to 812cc with just a nip and a flow test.

The Stock STi fuel pump is nothing special. Walboro's are cheap and good for more flow, I'd get one of those.
LW_Black4 likes this.

04 STi 16G powered lagless fun
04 WRX: SOLD
mosc is offline  
post #12 of 18 Old 02-21-2014, 06:44 PM
WRXtuners Member
 
psinuse's Avatar
 
Join Date: Nov 2004
Location: Ohio
Posts: 3,094
psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to psinuse is a WRX expert worth listening to
Those injectors won't work with your intake manifold...

You'll need these types of injectors.
Attached Images
 
turmic likes this.

Resident Grumpy Old Man(Keith)
03 SRP 2.34L
08' LGT Gears...
psinuse is offline  
post #13 of 18 Old 02-23-2014, 11:23 AM Thread Starter
WRXtuners Member
 
LW_Black4's Avatar
 
Join Date: Mar 2013
Location: Ontario, Canada
Posts: 494
Images: 7
LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful
Garage
Ok gents, I have an update.

Car Club folks are saying that my EJ205 block is not a good one for a stroker application, because of it's open deck block. Additional side loading of the bores from the longer stroke crank shifts the top of the cylinders bores resulting in premature head gasket failure, even in modest power applications.

I want reliabilty for my rebuild investment, so I don't think I'm taking this approach anymore.

I can buy an OEM shortblock from BuiltEJ and get them to include refreshed cylinder heads in exchange for the head cores, and it looks like this is the least expensive way to get a new motor. I believe it will be a semi-closed deck block item too, which is better than the shortblock it replaces.

This is handy because the motor could be swapped in a single (maybe long) weekend then, which reduces downtime.

https://www.facebook.com/22512505751...type=1&theater


Laszlo - blue '04 WRX
Meet the turbocharged rally-bred Subaru WRX.
blue '09 STi - lease return

Last edited by LW_Black4; 02-23-2014 at 12:39 PM.
LW_Black4 is offline  
post #14 of 18 Old 02-24-2014, 12:25 PM
Moderator
 
mosc's Avatar
 
Join Date: Mar 2005
Location: Pennsylvania
Posts: 6,499
Images: 7
mosc is a helpful contributing member
Garage
The only truly closed deck EJ motor that hit the US shores was the EJ22T from the 1991-1994 LGT. The top end of the motor is crap, SOHC, didn't even come with an intercooler but the block is excellent.
LW_Black4 likes this.

04 STi 16G powered lagless fun
04 WRX: SOLD
mosc is offline  
post #15 of 18 Old 02-24-2014, 01:26 PM Thread Starter
WRXtuners Member
 
LW_Black4's Avatar
 
Join Date: Mar 2013
Location: Ontario, Canada
Posts: 494
Images: 7
LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful LW_Black4 is known to be trustworthy and helpful
Garage
I'm told that even a semi-closed block construction is not required for an OEM build at modest power levels like I want, unless I'm trying to make a stroker 2.2L out of it as well.

Pictures of a semi-closed block. I think it's the ribbing that supports the top of the cylinder in four places along it's circumference that makes it semi-closed.

Semi-closed JDM block


In the same post, wall thickness difference between JDM 2.0 and USDM 2.5


Here's the FB link: https://www.facebook.com/photo.php?f...type=1&theater

Decided to go with an OEM build or rebuild now.

Laszlo - blue '04 WRX
Meet the turbocharged rally-bred Subaru WRX.
blue '09 STi - lease return

Last edited by LW_Black4; 02-24-2014 at 01:27 PM. Reason: Add link
LW_Black4 is offline  
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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 On
Trackbacks are On
Pingbacks are On
Refbacks are On