Ghetto swap questions :)

jordan-Richardo · 12-22-2018, 08:50 PM

Hey guys,

Short story is that I have a 2010 Forester as the wife's daily driver, and the current engine is a ej25 SOHC that we cobbled out of an '03 block with heads from an '09 for the AVCS.

After about 70K now, I am starting to see some brass in the oil...great. She doesn't drive much right now so it is good timing I guess but crap.

I have another EJ25 SOHC motor sitting here complete that is in reasonable shape, new HG's, timing belt, water pump etc.. BUT it's a 2001 without any AVCS of course.

I want to swap this motor in and run it to give myself some time for funds (baby in the works) and proper parts or a swap depending on what I find in the original engine. Would it run is the question, I realize that I will have CEL's going on but I am ok with that so long as it will still fire up and drive reasonably without the solenoids connected for the AVCS etc. Also guessing I need to swap crank sprocket and possibly cam pulleys too?

Any help is greatly appreciated

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jordan-Richardo · 12-22-2018, 09:20 PM

I should mention that I plan to use the intake from the current engine for the electronics.

Blktrax · 12-22-2018, 09:57 PM

You may have an issue with the diameter of the crank pilot hole/flex plate mounting, the older ej20 from base Imprezas vs. the needed beef of the ej25

jordan-Richardo · 12-22-2018, 10:46 PM

Ah sorry I typo-ed there and edited. Both are EJ25's

Blktrax · 12-22-2018, 10:58 PM

2000 and up EJ25 are all phase 2 blocks. On AVCS heads you have one Metal (left-driver)and one plastic (right-passenger) cam gear; non-avcs =both metal.

The driver side has the correct cam sensor pickups for the ECM. You would need to swap the avcs cam pulley and cam sensor.

Just count the teeth on the crank sprocket I’m almost certain you need to swap the sprocket with the crank sensor as well.

Yes you will have a check engine light, but it may go into limp mode because there is no oil pressure feedback from either pressure sensor or the oil temp sensor on the right (passenger)head. That’s uncharted territory.

jordan-Richardo · 12-22-2018, 11:27 PM

Awesome thank you!

Limp mode isn't so awful on a non turbo from what I've experienced if it comes to that. I believe there was no rev limitation just really crap gas mileage lol.

I'm thinking of getting a reading off of those sensors from the current engine and being able to hopefully wire up a little circuit to emulate a pressure condition, I'm imagining it could be a static voltage so long as I get it within the expected range for the pressure at least?

jordan-Richardo · 12-22-2018, 11:29 PM

I forgot to ask as well:

The heads have black plastic? cam gears without the protruding AVCS portion, but I have two additional sensors on each head which I was led to believe is single AVCS?

Just wanted to confirm that before continuing down the rabbit hole here haha

Blktrax · 12-22-2018, 11:35 PM

Resistors in line should get static values , but operating at temp to get those values would be a chore.

jordan-Richardo · 12-22-2018, 11:40 PM

I was thinking of hooking the oscilloscope to it and going for a coffee run haha. Thankfully I have a ton of electronics gear, but yeah definitely not a project I am at all interested in. This just feels like a really dirty hack and it being the wife's car means that I will no doubt get to hear all about it every step of the way :P

12-22-2018, 08:50 PM	#1
jordan-Richardo Scooby Newbie Member#: 470693 Join Date: Jul 2017	Ghetto swap questions :) Hey guys, Short story is that I have a 2010 Forester as the wife's daily driver, and the current engine is a ej25 SOHC that we cobbled out of an '03 block with heads from an '09 for the AVCS. After about 70K now, I am starting to see some brass in the oil...great. She doesn't drive much right now so it is good timing I guess but crap. I have another EJ25 SOHC motor sitting here complete that is in reasonable shape, new HG's, timing belt, water pump etc.. BUT it's a 2001 without any AVCS of course. I want to swap this motor in and run it to give myself some time for funds (baby in the works) and proper parts or a swap depending on what I find in the original engine. Would it run is the question, I realize that I will have CEL's going on but I am ok with that so long as it will still fire up and drive reasonably without the solenoids connected for the AVCS etc. Also guessing I need to swap crank sprocket and possibly cam pulleys too? Any help is greatly appreciated * Registered users of the site do not see these ads. Last edited by jordan-Richardo; 12-22-2018 at 10:46 PM.

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12-22-2018, 09:20 PM	#2
jordan-Richardo Scooby Newbie Member#: 470693 Join Date: Jul 2017	I should mention that I plan to use the intake from the current engine for the electronics.

12-22-2018, 09:57 PM	#3
Blktrax Scooby Specialist Member#: 220971 Join Date: Aug 2009 Chapter/Region: South East Location: West, NC Vehicle: 2002 WRX 223K Mi.	You may have an issue with the diameter of the crank pilot hole/flex plate mounting, the older ej20 from base Imprezas vs. the needed beef of the ej25

12-22-2018, 10:46 PM	#4
jordan-Richardo Scooby Newbie Member#: 470693 Join Date: Jul 2017	Ah sorry I typo-ed there and edited. Both are EJ25's

12-22-2018, 10:58 PM	#5
Blktrax Scooby Specialist Member#: 220971 Join Date: Aug 2009 Chapter/Region: South East Location: West, NC Vehicle: 2002 WRX 223K Mi.	2000 and up EJ25 are all phase 2 blocks. On AVCS heads you have one Metal (left-driver)and one plastic (right-passenger) cam gear; non-avcs =both metal. The driver side has the correct cam sensor pickups for the ECM. You would need to swap the avcs cam pulley and cam sensor. Just count the teeth on the crank sprocket I’m almost certain you need to swap the sprocket with the crank sensor as well. Yes you will have a check engine light, but it may go into limp mode because there is no oil pressure feedback from either pressure sensor or the oil temp sensor on the right (passenger)head. That’s uncharted territory.

12-22-2018, 11:27 PM	#6
jordan-Richardo Scooby Newbie Member#: 470693 Join Date: Jul 2017	Awesome thank you! Limp mode isn't so awful on a non turbo from what I've experienced if it comes to that. I believe there was no rev limitation just really crap gas mileage lol. I'm thinking of getting a reading off of those sensors from the current engine and being able to hopefully wire up a little circuit to emulate a pressure condition, I'm imagining it could be a static voltage so long as I get it within the expected range for the pressure at least?

12-22-2018, 11:29 PM	#7
jordan-Richardo Scooby Newbie Member#: 470693 Join Date: Jul 2017	I forgot to ask as well: The heads have black plastic? cam gears without the protruding AVCS portion, but I have two additional sensors on each head which I was led to believe is single AVCS? Just wanted to confirm that before continuing down the rabbit hole here haha

12-22-2018, 11:35 PM	#8
Blktrax Scooby Specialist Member#: 220971 Join Date: Aug 2009 Chapter/Region: South East Location: West, NC Vehicle: 2002 WRX 223K Mi.	Resistors in line should get static values , but operating at temp to get those values would be a chore.

12-22-2018, 11:40 PM	#9
jordan-Richardo Scooby Newbie Member#: 470693 Join Date: Jul 2017	I was thinking of hooking the oscilloscope to it and going for a coffee run haha. Thankfully I have a ton of electronics gear, but yeah definitely not a project I am at all interested in. This just feels like a really dirty hack and it being the wife's car means that I will no doubt get to hear all about it every step of the way :P