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EJ25 block with EJ22 heads


hirsch58
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Ok, I have read many forums with many conflicting replies with the following pursuit.  A Ej25 block with EJ22 heads for higher compression.

 

The following are my perameters of the build that I hope you guys can help me with.

 

1). I have limited room for this build. This is not going into subaru, so I have a maximum engine width to be 28 1/2", rocker cover to rocker cover. so I believe I will need phase 1 heads to do this.

2). I would like it to be SOHC. not DOHC not enough room and heavier.

3). It must be NA, so no forced induction of any kind please.

4). I would like it use existing available parts from donor.

5). Which ECU for up to 6500rpm?

6). Which head gaskets and will I need? And will I need to port the combustion chamber to match the cylinders?

7). Any other info that would help?

8). What would the estimated compression come to?

 

What is the best way to start this project and with what phases,1 or 2 and years of these heads and blocks

 

I would like the outcome to be around 185 crank hp or more if possible. And be a more mid range rpm. I don't require a high revving  motor.

Edited by hirsch58
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I have no idea about overall final width. Use the 2.5 headgaskets. I've done this swap without doing any machine work to the heads and it worked out ok. The 2.5 ECU has a 6500 rpm redline, if you're going for phase1 ej22 heads you'll want to use the DOHC computer.

The rule of thumb is use headgaskets that match the block, use a timing belt that matches the heads.

If you want different cams check out Delta, they do regrinds for subaru cams. You probably want the 1500 version for midrange.

 

I have no idea what the final horsepower is. I put 2.2 heads on a 2.5 block and butt dyno said it had a decent amount more horsepower than a stock 2.5. 2.2 heads flow like garbage and I never dyno'd it, though. 

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Ok, I have read many forums with many conflicting replies with the following pursuit.  A Ej25 block with EJ22 heads for higher compression.

 

The following are my perimeters of the build that I hope you guys can help me with.

 

1). I have limited room for this build. This is not going into subaru, so I have a maximum engine width to be 28 1/2", rocker cover to rocker cover. so I believe I will need phase 1 heads to do this.

2). I would like it to be SOHC. not DOHC not enough room and heavier.

3). It must be NA, so no forced induction of any kind please.

4). I would like it use existing available parts from donor.

5). Which ECU for up to 6500rpm?

6). Which head gaskets and will I need? And will I need to port the combustion chamber to match the cylinders?

7). Any other info that would help?

8). What would the estimated compression come to?

 

What is the best way to start this project and with what phases,1 or 2 and years of these heads and blocks

 

I would like the outcome to be around 185 crank hp or more if possible. And be a more mid range rpm. I don't require a high revving  motor.

Wow, this could have been posted by me.  The perameters are almost exactly what I'm looking for...except the hp.  I'm thinking more along the line of 165-170hp.  Mine is going into a '74 Super Beetle.  I have a good friend named Joel who has built the exact engine you're asking about.  If you are, indeed, installing into a Beetle, I can connect you to him.

 

johnL (aka H2OSB)

www.superbeetlesonly.com

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johnL (aka H2OSB)  

 

First thanks for taking the time to reply. You can connect me with Joel if you like too.

 

Its not going into a VW though, however the parameters are very close, just mounts differently. The reason for the EJ motor is it's light weight, smooth acceleration, low center of gravity and decent power. I have worked on subaru motors and really like the simplicity. I am just 

not well versed in the substitution of parts yet. I would like to do a formal write up of this particular combination of parts soon after this build for guys out there wanting to do this too.

Any other thoughts out there would be much appreciated. Remember this is to be a NA SOHC phase 2 EJ251 block or ? with phase 1 heads (dual port I hope) with a maximum width of 28 1/2" with (rocker cover to rocker cover).

If you know the years and vehicles these parts come from, please reply. The reason I'm using the phase 1 heads to keep the motor width at 28 1/2", I believe phase 2 are too tall.

How would I start this build, start with a EJ25 engine and swap the  heads for  Ej22's  or start with a EJ22 motor and get a EJ25 short block because I am thinking of all the other components compatibilty like manifolds and sensors too?  

 

Thanks Jeff

Edited by hirsch58
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Phase I EJ25 is DOHC engines are found in:

1996-1999 Legacy and Outback

1998 Forester and Impreza RS

 

Phase II EJ25 SOHC engines:

All 2000 and up engines

1999 Forester and Impreza RS

 

EJ22's 1998 and earlier:  (1999-2001 are Phase II heads and the same dimensions....essentially the same head except the exhaust ports...as Phase II EJ25 heads):

some years have HLA's and some have solid rockers - you probably want to determine which of those is most ideal for your situation and chose that way.

1995 EJ22's are dual port exhaust (same exhaust manifold as EJ25)

1996-1998 are single port exhaust

 

parts acquisitions could go either way.  heads match the intake and exhaust manifolds so that is all nice to get together and then swap whatever block you want - the blocks are completely interchangeable with nothing dependent on them so that's the benign side of the equation.

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grossgary

 

Thanks grossgary for taking the time to reply. The info was also helpful. I think I am getting a little more familiar with the EJ's.now.

 

I am heading to the pick a part yard tomorrow to physically measure the motor width. I am assuming EJ25 and EJ22 have a similar deck height that is close enough to give me an 

accurate overall motor width.

 

I am not familiar with what HLA  rockers are?

 

 

Ok I am back from the pick-a-part now, and yes the width of a ej22 sohc is 28 1/2" wide in all the engines I measured. So that part of the equation works out. However:

 

1). Are 95 ej22 heads the only year heads that are SOHC and dual port or are there other years too with EGR tube port or not???

2). If any one has knowlege of oil pan shortening, about 3".  I have room to add to the front of the pan to make up for the 4-5 quart capacity and pick up tube.

3). Also do the 95 sohc phase1 heads have the smaller cc combustion chambers?

Edited by hirsch58
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