EJ25 Block(s) Question

drdolil99 · 05-09-2018, 09:36 AM

So I have been browsing the forums and can't seem to get a straight answer. I am hoping here someone can give me the answer I am looking for... or at least an answer.

I have a 2006 Impreza 2.5i and it has a spun bearing. The Engine is out and I just want to replace the block.

Is there a difference between the EJ251, EJ253, EJ255, EJ257 Blocks? I found this block from Procom Racing for only $1K and asked if they

https://www.procomracing.com/shoppro...ock-p101454063

I looked in the service manual for both the EJ253 and EJ257 and the measurements all seem to be exactly the same for the Pistons, Piston Rings, Connecting Rods and Crankshaft, but the part numbers for the pistons and piston rings are different on Subaru's website.

If I put my ej253 heads on there I don't want to have low compression.

If any of you guys know where I can find a rebuilt ej253 block for about that price. I would appreciate it, otherwise is this the same as an EJ253 block.

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pcampbell · 05-09-2018, 05:51 PM

That is going to be the wrong (lower) compression for your Impreza, unless you are planning on boosting it, then it would be perfect.

Basically you would lose a bit of power if you put that in your Impreza.. but, if you planned on turbo or supercharging the car, it'd be perfect and now would be the time to do it (and put in a better clutch too)!!!!

I am not sure but around here you can find a rebuilt long block 253 for like $1500 with a core.

The case halves, rods, pistons, and presumably bearings and rings are different. The crankshaft is the same.

These guys would probably rebuild your 253 for the same price as a 257. It is really not cheaper (unfortunately).

v2rocket_aka944 · 05-12-2018, 12:41 PM

you can get a fresh short block from Subaru directly for ~$2100.

Raymondt · 06-11-2024, 10:54 AM

are the ej251 and ej255 the same?

05-09-2018, 09:36 AM	#1
drdolil99 Scooby Newbie Member#: 154939 Join Date: Jul 2007 Location: Phoenix Vehicle: 2019 WRX Limited WR Blue Pearl	EJ25 Block(s) Question So I have been browsing the forums and can't seem to get a straight answer. I am hoping here someone can give me the answer I am looking for... or at least an answer. I have a 2006 Impreza 2.5i and it has a spun bearing. The Engine is out and I just want to replace the block. Is there a difference between the EJ251, EJ253, EJ255, EJ257 Blocks? I found this block from Procom Racing for only $1K and asked if they https://www.procomracing.com/shoppro...ock-p101454063 I looked in the service manual for both the EJ253 and EJ257 and the measurements all seem to be exactly the same for the Pistons, Piston Rings, Connecting Rods and Crankshaft, but the part numbers for the pistons and piston rings are different on Subaru's website. If I put my ej253 heads on there I don't want to have low compression. If any of you guys know where I can find a rebuilt ej253 block for about that price. I would appreciate it, otherwise is this the same as an EJ253 block. * Registered users of the site do not see these ads.

05-09-2018, 05:51 PM	#2
pcampbell Scooby Specialist Member#: 437670 Join Date: Jan 2016 Location: VT Vehicle: 2005 2.5 SC OB	That is going to be the wrong (lower) compression for your Impreza, unless you are planning on boosting it, then it would be perfect. Basically you would lose a bit of power if you put that in your Impreza.. but, if you planned on turbo or supercharging the car, it'd be perfect and now would be the time to do it (and put in a better clutch too)!!!! I am not sure but around here you can find a rebuilt long block 253 for like $1500 with a core. The case halves, rods, pistons, and presumably bearings and rings are different. The crankshaft is the same. These guys would probably rebuild your 253 for the same price as a 257. It is really not cheaper (unfortunately). Last edited by pcampbell; 05-09-2018 at 06:19 PM.

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05-12-2018, 12:41 PM	#3
v2rocket_aka944 Scooby Newbie Member#: 408701 Join Date: Dec 2014	you can get a fresh short block from Subaru directly for ~$2100.

06-11-2024, 10:54 AM	#4
Raymondt Scooby Newbie Member#: 538253 Join Date: Jun 2024 Location: Virginia Vehicle: 2001 Forester Gold	are the ej251 and ej255 the same?