Legacy 2.5i 2005 vs EJ20 SOHC N/A JDM

[Ryoko]

Hi I want to replace the 2.5 in my 2.5i 2005 with the jdm 2.0 Sohc jdm and wondered if it was compatible beside maybe intake and any other things? Reason is the 2.0 seems to be more reliable than the 2.5..I am talking about the 2.0 N/A (non-turbo).

 

And if its do-able what does it involve and has to be changed, or changed over etc..thanks

[GEE-OTTO]

You prob found a JDM 2.0 for sale for cheap right? If your 2.5 is blown rebuild it or find another EJ253 to swap in, the JDM will require the JDM ECU and youll have to deal with any mismatched wiring issues. Youll also be down on power slightly.

[Ryoko]

Alright thanks. I dont really want to put another 2.5, I might swap in the 2.0. I was aware for the 2.0 being less powerful than the 2.5 but not by much we are talking about 10hp of differences. Im more concerned about reliability

[Ryoko]

The shop guy told me that it came from a 2002-2007 (JDM model year) so I assume its their "2.0i"?

[halwith]

this seems like alot of work for very little if any gains.

[Ryoko]

No gain but loss of 10hp, like I said im more concerned about reliability, the 2.0 seems to be more reliable than the 2.5. I can have one for 750 at a jdm shop. Im really tempted for that swap. He told me you might need to keep your intake to make it work. Everything else would be direct swap.

[halwith]

I didnt mean hp when I said gains. You had stated you wanted to gain reliability with your swap.

[GEE-OTTO]

This shop guy is feeding you a load of BS. What mechanic's first piece of advice is to swap engines with a JDM unit that requires a decent amount of wiring to make run? Second how do you know how well the JDM engine was maintained? Do a search on this or any Subaru forum see how many folks fix a blown Ej253 with a JDM EJ20

 

Your 2.5i is as reliable as you maintain it to be So i would dismiss that notion and any JDM advice a shop is giving you. If you want a running salvaged engine swap in a running EJ253 plug and play and cheap.

[Ryoko]

Alright ill buy another ej253 I know they are reliable if well cared, my dads 2.5i has over 300 000km on its original engine and running like new, no leak, no burning oil.

 

I just have a phobia on blowing headgaskets and having it overheating. It really is my main concerns on 2.5 n/a.

[krot84]

As far as I know the last jdm sohs 2.0 was made in 2005 which had 137 hp, Afterwords they made a dohs with 165hp and the JDM 2007-2008 had the ej204 with 150 which had more torque than the 165 version. If I were you I'd stay with the 2.5 sohs, it has more torque and HP.

 

Sent from my Nexus 5 using Tapatalk

[halwith]

If your fear is blown headgaskets replace factory set and flush your coolant regularly.

[GEE-OTTO]

Alright ill buy another ej253 I know they are reliable if well cared, my dads 2.5i has over 300 000km on its original engine and running like new, no leak, no burning oil.

 

I just have a phobia on blowing headgaskets and having it overheating. It really is my main concerns on 2.5 n/a.

 

Yeah that is here say mostly. And more so with the older EJ25D than the EJ253. 05 being the "new" year for that engine it should be expected to have some issues. If you really want to swap, used a 06-09 EJ253 but it would be about as much work if not more than a JDM engine

[Ryoko]

After months searching for a decent priced and engine I came to the conclusion of a jdm swap, EJ20X/Y from the jdm Legacy 2.0GT.

 

Before anything..I need to know for sure if there are any reasons why it would not work and not work properly. Keep in mind the car is a bone stock Legacy Outback 2.5i 2005 with manual transmission.

 

Yes in the deal I have everything I need to swap such as complete engine 5speed tranny harness ecu downpipes rear diff maybe some other stuff I forgot.

 

What about the immobilizer? The Quad AVCS found on the EJ20X/Y? Etc..

 

No selling the car to get myself a GT or XT is not an option. This will be a complete swap and I need to know for sure that it will start and drive. I did alot of search and could not find anything useful..

 

The EJ20X are cheaper than any EJ205 from the WRX, that is one of the reason why I wont be going with the EJ205. Thanks for any input.

[GEE-OTTO]

So your goal is to swap for more power? OR to swap to replace a bad engine? IF you go EJ20X route youll need to do some frame mods to the accommodate the up pipe, merge the harnesses and upgrade you fueling system and clutch.

[Ryoko]

Ill buy a crossmember from a turbo model so that wont be an issue, as for the fueling system and clutch I guess I will have these in the package, I am aware of the harnesses swap I will have a friends helping me doing it. I am doing the complete swap for both reasons to replace and to gain some more power. I also might get the EJ205 instead I am negociating on the prices of both engines drivetrain. It will depends which packages gets the best deal. Either way my concern is about making it works. I dont want to lose 2 grands(can $) on something that wont works. I will keep you guys updated on the swap. I bought a used LGT hood for cheap

[WCFD2509]

I'm going to revive this thread from the dead. Sorry ahead of time.

 

My reason is because of inaccurate information.

 

For anyone wanting to do the JDM Phase 2 EJ20 SOHC swap to replace their EJ251/3, here is what you need to know.

 

1. The USDM EJ251/3 is the same casting as the JDM EJ20 SOHC. So the engine physically drops right onto your factory mounts and bolts right up to any EJ transmission. Use your USDM clutch and flywheel for the EJ251/3. (The thermostat housing is the same design too, and you'll be fine using the USDM thermostat.)

 

2. You don't need to rewire anything. Just swap your intake manifold and sensors over. Although the sensors are the same part number as your USDM motor, it's a better idea to swap the sensors you know work from your motor.

 

The intake manifold MUST be swapped over because the MAP and IAT sensors are not a one sensor setup like your EJ251/3, the EJ20 SOHC MAP and IAT are two separate sensors like the EJ25D.

 

3. Swap the driver's side cam gear and crank gear over from your EJ251/3. You Must do this because the triggers are different. If you don't, your ecu won't be able to start it, and if it somehow does, it'll run like crap.

 

So swap them over when you replace the timing belt kit (same as EJ251/3 BTW).

 

 

 

So, now you swapped the intake manifold, cam and crank gears, replaced any dry rotted gaskets/hoses, and the motor is in the car mated to the transmission. Now what?

 

Plug everything back in and do your first start procedures (fluids, double checking bolt torque specs, etc....), and fire that kitten up.

 

No that is not a Honda engine running, it's a wonderful specimen of Japanese engine design and assembly that makes USDM engines seem like a Diesel engine when compared to this baby.

 

But no, seriously guys, the JDM EJ20 SOHC runs SOOO much smoother than any USDM Subie motor I've ever seen or heard. They rev better and smoother, and the idle is amazingly smooth. These motors remind me of the good old USDM phase 1 EJ22's that go on forever, but smoother.

 

You'll notice a bit of torque loss difference, but not much, the most noticeable thing is how smooth this engine performs its duties, which tells me that Japan has EJ assembly down to a beautifully artful science.

 

And the ECU has no issues running the smaller displacement motor. The AFR's are normally a little lean on factory USDM EJ25 SOHC tunes (more so on 4eat's than 5mt's), so running this new engine with your 2.5L injectors works very well. Even in open loop under WOT.

 

Note: the 2000-2004 JDM EJ20 SOHC doesn't have EGR. It's a easy drill and tap to install yours if you need to pass inspection. Just search for the write ups.

 

Also, 2005+ JDM EJ20 SOHC's didn't start avcs until later (I don't know what year got them, sorry), so you could either swap your heads over, or you could open source tune and eliminate the AVCS codes so it won't throw your ecu into Limp Mode (again search the forums). High horse power turbo guys do this all of the time.

 

Any questions?

[GEE-OTTO]

Good information not sure why a 06+ owner would want to swap in a EJ202 if their EJ253 failed but they are cheap so I could help someone in a pinch i reckon.

[Ryoko]

I'm going to revive this thread from the dead. Sorry ahead of time.

 

My reason is because of inaccurate information.

 

For anyone wanting to do the JDM Phase 2 EJ20 SOHC swap to replace their EJ251/3, here is what you need to know.

 

1. The USDM EJ251/3 is the same casting as the JDM EJ20 SOHC. So the engine physically drops right onto your factory mounts and bolts right up to any EJ transmission. Use your USDM clutch and flywheel for the EJ251/3. (The thermostat housing is the same design too, and you'll be fine using the USDM thermostat.)

 

2. You don't need to rewire anything. Just swap your intake manifold and sensors over. Although the sensors are the same part number as your USDM motor, it's a better idea to swap the sensors you know work from your motor.

 

The intake manifold MUST be swapped over because the MAP and IAT sensors are not a one sensor setup like your EJ251/3, the EJ20 SOHC MAP and IAT are two separate sensors like the EJ25D.

 

3. Swap the driver's side cam gear and crank gear over from your EJ251/3. You Must do this because the triggers are different. If you don't, your ecu won't be able to start it, and if it somehow does, it'll run like crap.

 

So swap them over when you replace the timing belt kit (same as EJ251/3 BTW).

 

 

 

So, now you swapped the intake manifold, cam and crank gears, replaced any dry rotted gaskets/hoses, and the motor is in the car mated to the transmission. Now what?

 

Plug everything back in and do your first start procedures (fluids, double checking bolt torque specs, etc....), and fire that kitten up.

 

No that is not a Honda engine running, it's a wonderful specimen of Japanese engine design and assembly that makes USDM engines seem like a Diesel engine when compared to this baby.

 

But no, seriously guys, the JDM EJ20 SOHC runs SOOO much smoother than any USDM Subie motor I've ever seen or heard. They rev better and smoother, and the idle is amazingly smooth. These motors remind me of the good old USDM phase 1 EJ22's that go on forever, but smoother.

 

You'll notice a bit of torque loss difference, but not much, the most noticeable thing is how smooth this engine performs its duties, which tells me that Japan has EJ assembly down to a beautifully artful science.

 

And the ECU has no issues running the smaller displacement motor. The AFR's are normally a little lean on factory USDM EJ25 SOHC tunes (more so on 4eat's than 5mt's), so running this new engine with your 2.5L injectors works very well. Even in open loop under WOT.

 

Note: the 2000-2004 JDM EJ20 SOHC doesn't have EGR. It's a easy drill and tap to install yours if you need to pass inspection. Just search for the write ups.

 

Also, 2005+ JDM EJ20 SOHC's didn't start avcs until later (I don't know what year got them, sorry), so you could either swap your heads over, or you could open source tune and eliminate the AVCS codes so it won't throw your ecu into Limp Mode (again search the forums). High horse power turbo guys do this all of the time.

 

Any questions?

 

Okay sorry to revive my old thread again but years has passed by and alot has changed anyway, if you guys still around uh I got a couple of question well as of now I have a nice deal on this 2007 Legacy 2.5i Limited. Its a small garage sale so the guy said car is driving good but engine is overheating, no smokes coming out from the exhaust.

 

I know 06+ have avcs ou whatever that is called so I can't just drop a jdm 2.0 and drive away. So what is exactly I need to do to run the 2.0? (I have zero interest in dropping another 2.5) what is the open source thing exactly?