saab92x.com - Over 10% of all 9-2x owners registered

Saab92x.com is dedicated to the discussion of the Saab 9-2x sport wagon, based on the Subaru WRX.
Please register or login to post.

Welcome to Saab92x.com!
Saab92X.com is the premier Saab92X forum on the internet. Registered Users do not see the above ads.Please Register - It's Free!

#1 2019-02-06 10:45:40

mark458
Member
Registered: 2019-02-06
User Number: 46321
Posts: 3

Engine swap... Can it be done?

I have an 05 Aero with a blown engine and want to put a 2.5 either out of an 06 or a JDM. Can I do it without any major mods? Are any mods required or can I drop it in a go?

Last edited by mark458 (2019-02-06 10:48:02)

Offline

 

Remove Advertisements Advertisement

Saab92X.com

Offline

 

#2 2019-02-06 11:02:17

snowphun
Member
From: Central CT
Registered: 2005-11-09
User Number: 890
Posts: 598

Re: Engine swap... Can it be done?

Since it's an Aero you're in good shape, either no wiring or if you want AVCS minimal wiring needs to be done. But still lots to consider, pros and cons to different approaches, search on NASIOC for details. I have an ej255 that was installed into a MY05 Aero, it needed the Cosworth cam bracket, ej205 IM and a few other bits.

Offline

 

#3 2019-02-06 11:10:22

mark458
Member
Registered: 2019-02-06
User Number: 46321
Posts: 3

Re: Engine swap... Can it be done?

From what I was able to find, Id have to swap out the crank sprocket, left cam sprocket, intake and exhaust manifolds. If that's all I have to do Im happy to do it...

Offline

 

#4 2019-02-06 15:04:42

mark458
Member
Registered: 2019-02-06
User Number: 46321
Posts: 3

Re: Engine swap... Can it be done?

Is that all that needs to be done? Whats this wiring that needs to be done?

Offline

 

#5 2019-02-25 13:10:52

elislider
accept no substitutes
Registered: 2014-11-30
User Number: 25881
Posts: 504

Re: Engine swap... Can it be done?

Forget what he said. you CANNOT run an EJ255 (06+ WRX) motor on the wiring or ECU in your car. They are totally incompatible due to cam signalling differences (in wiring and sensors)
If you wanted to do that you would basically have to do a wiring conversion which would involve merging parts of the EJ255/EJ257 wiring into your EJ205 body harness, and then using the correct ECU.
that IS an option, its basically the exact same process as doing an STi engine swap.

The cheapest option is to either find a good running stock replacement motor for your EJ205 or rebuild the one you have. It would be predictable, reliable, and low complexity.

If you get a JDM EJ20 import motor with intake AVCS, it would have to be one of the early engines with 2-wire rear cam sensors and the 2 wire front (left intake) cam sensor.
This engine can run without AVCS on your stock ECU, though it would definitely want to get a tune.
Or you can get the IAG AVCS wiring add-on https://iatuning.com/products/subaru-av … l-bulkhead - and then get the JDM ECU (also strongly recommended to get a tune as well for USA gas)

Offline

 

#6 2019-02-25 16:16:21

snowphun
Member
From: Central CT
Registered: 2005-11-09
User Number: 890
Posts: 598

Re: Engine swap... Can it be done?

elislider wrote:

Forget what he said. you CANNOT run an EJ255 (06+ WRX) motor on the wiring or ECU in your car. They are totally incompatible due to cam signalling differences (in wiring and sensors)
If you wanted to do that you would basically have to do a wiring conversion which would involve merging parts of the EJ255/EJ257 wiring into your EJ205 body harness, and then using the correct ECU.
that IS an option, its basically the exact same process as doing an STi engine swap.

Whoa, slow your roll a bit. I'm far from an expert on this stuff but an EJ255 can be used in a 16 bit car (like an 05 Aero), with a few changes which OP mentioned above. It does not require rewiring nor running the ej255 ECU. I'm sure there are other caveats I'm not familiar with but as I mentioned I bought a wrecked MY05 Aero with a EJ255 in it and it was running.

Offline

 

#7 2019-03-01 03:05:59

elislider
accept no substitutes
Registered: 2014-11-30
User Number: 25881
Posts: 504

Re: Engine swap... Can it be done?

Its not nearly as simple as you're making it out to be.
mark458 mentioned "swap out the crank sprocket, left cam sprocket, intake and exhaust manifolds"
crank gears are the same. cam gears are totally different and intake ones are not swappable. the heads themselves are drastically different including the types and locations of the cam sensors (EJ205 has 1 at the cam gear and EJ255/EJ257 are on the rear of each intake cam). intake manifolds have to match the wiring/ECU type since thats where all the other sensors basically go. exhaust manifolds are swappable and/or basically the same.

So any EJ motor can be used in an EJ-based chassis. But if you want to run an EJ255/EJ257, you need the wiring and ECU for it. and the gas pedal (drive by wire).
there are significant wiring differences that are not simple to implement. basically you'd be doing a wiring conversion.

Offline

 

#8 2019-04-23 00:35:42

Rodman
Member
From: Long Island
Registered: 2006-03-01
User Number: 1046
Posts: 2527

Re: Engine swap... Can it be done?

What about a proper hybrid, stock ej257 short block and modified usdm ej205 heads or an ej257 with hybrid specific pistons ?
With a set of jdm avcs ej205 or ej207, avcs wiring and jdm avcs ecu he could stay with the 16bit wire platform on the 2005 aero and have functional avcs.

Last edited by Rodman (2019-04-23 00:39:31)


2005 satin gray metalic aero, sold. 06 wrx, adios!
2005 black aero, rescue project, jdm STi ver 7 drivetrain.
2005 desert silver aero, work horse JDM EJ205 AVCS
2002 bugeye, sedan :-( new project

Offline

 

#9 2019-04-23 21:37:59

elislider
accept no substitutes
Registered: 2014-11-30
User Number: 25881
Posts: 504

Re: Engine swap... Can it be done?

^ yes. thats just a lot of work

Offline

 

#10 2019-04-25 01:34:30

Rodman
Member
From: Long Island
Registered: 2006-03-01
User Number: 1046
Posts: 2527

Re: Engine swap... Can it be done?

A 257 short block with machined usdm ej205 heads would be the simplest way.


2005 satin gray metalic aero, sold. 06 wrx, adios!
2005 black aero, rescue project, jdm STi ver 7 drivetrain.
2005 desert silver aero, work horse JDM EJ205 AVCS
2002 bugeye, sedan :-( new project

Offline

 

#11 2019-05-04 13:37:55

TrailerParkNinja
Member
Registered: 2015-07-26
User Number: 32504
Posts: 68

Re: Engine swap... Can it be done?

Hey Rodman,

Could you elaborate on "machined" usdm ej205 heads?  I'm guessing this means more than just having the mating surface of the heads machined to be coplanar?

As well are you saying no ECU or harness modifications are needed with a ej257 short block and the original ej205 components bolted on?

Thank you all for sharing your wisdom!!!

Offline

 

#12 2019-05-08 21:30:39

Rodman
Member
From: Long Island
Registered: 2006-03-01
User Number: 1046
Posts: 2527

Re: Engine swap... Can it be done?

It's known as a hybrid engine build, the 2.0 cylinder heads get a slight modification to match the 2.5 cylinder bore. There are shops like IAG, Outfront and Andrewtech that are well known for the modification needed. You would use an STi cylinder head gasket and bolt on all the parts off the 2.0l motor. You will want to get a proper tune for it when is all done.


2005 satin gray metalic aero, sold. 06 wrx, adios!
2005 black aero, rescue project, jdm STi ver 7 drivetrain.
2005 desert silver aero, work horse JDM EJ205 AVCS
2002 bugeye, sedan :-( new project

Offline

 

#13 2019-05-11 03:01:02

elislider
accept no substitutes
Registered: 2014-11-30
User Number: 25881
Posts: 504

Re: Engine swap... Can it be done?

Machining the EJ205 heads for a hybrid build is not necessarily to match the bore, thats not really the important part (though it is a factor). the important part is compression ratio; the EJ205 heads have a smaller dish so by machining out material you gain some dish and drop the compression

Offline

 

#14 2019-05-11 20:33:45

Rodman
Member
From: Long Island
Registered: 2006-03-01
User Number: 1046
Posts: 2527

Re: Engine swap... Can it be done?

It’s a rather simple modification needed and all the rest of the 2.0L motor parts bolt on.


2005 satin gray metalic aero, sold. 06 wrx, adios!
2005 black aero, rescue project, jdm STi ver 7 drivetrain.
2005 desert silver aero, work horse JDM EJ205 AVCS
2002 bugeye, sedan :-( new project

Offline

 

Board footer

Site problems, bugs, or questions? Contact Administrator
All content copyright Saab92x.com 2005-2010
SAAB and the SAAB logos are trademarks of Saab Cars USA, Inc.