[mtcs]

Well,
found out that the 2000 Impreza 2.5rs I bought doesn’t have a EJ257 in it like I was told it did. Wow. Really pissed! Too bad Craigslist isn’t like eBay and I can complain and get some money back...

Anyways, it seems to be holding up to the punishment that I have been putting it through. Have been running a stock EJ251 at 10lbs of boost for over 5 months and still have full compression. Vishnu turbo kitted.

Does anyone know how much punishment these stock pistons and rods can take? Can I tune it for any higher boost (more than 10psi) without it blowing up or snapping a rod? Doing a EJ257 and STI swap in the winter but for now, I want to get as much outta this car as I can.

Any thoughts?

Ben

 

[Jefff]

Well,
found out that the 2000 Impreza 2.5rs I bought doesn’t have a EJ257 in it like I was told it did. Wow. Really pissed! Too bad Craigslist isn’t like eBay and I can complain and get some money back...

Anyways, it seems to be holding up to the punishment that I have been putting it through. Have been running a stock EJ251 at 10lbs of boost for over 5 months and still have full compression. Vishnu turbo kitted.

Does anyone know how much punishment these stock pistons and rods can take? Can I tune it for any higher boost (more than 10psi) without it blowing up or snapping a rod? Doing a EJ257 and STI swap in the winter but for now, I want to get as much outta this car as I can.

Any thoughts?

Ben

umm if you rely on the car for a DD then turn the boost down..RIGHT NOW.....u can handle 7 lbs, maybe 8 top with stock ej251..but 10psi is just asking for it...

 

[GregBolby]

ive had 7psi on my motor for atleast 50k

 

[drummerRS2505]

yeah i would do as Jeff said and turn it down till you swap with sti. then you can save or sell your old lump maybe.

 

[InsatiableAmos]

As long as it's tuned well, you should be fine...

 

[2.5rsleeper]

+1 for turning down the boost, it's not so much the engine i'd be worried about it's the tranny, boosted high comp EJ251's love to blow trannies

 

[scootfd3s]

i have an ej25. the previous owner says they swappd it(ej25 jdm) in the 99' , because the orignal ej22 blew.. so how can i identify what kind of ej25 i have? this guy makes me scared... i hope i have an ej257 like the one the poster wants so much.

 

[Jefff]

i have an ej25. the previous owner says they swappd it(ej25 jdm) in the 99' , because the orignal ej22 blew.. so how can i identify what kind of ej25 i have? this guy makes me scared... i hope i have an ej257 like the one the poster wants so much.

well for usdm stuff this is about the only way i can think of to tell right now:

ok on the top of the block, towards the back of the passenger side theres a breather that goes to the pcv system.....the ej251 only has this breather....and ej257 will have another one about 6" to the right (center of the block)...it'll most likely be blocked off.

but hopefully someone knows more than i do and chimes in.

 

[Brydon]

^^^ that would be the easiest way to tell.

The original poster could even have STI internals in a RS case. How do we know this is not a ej257.

And the guy that has the "JDM ej25" Why would you want a ej257 in a NA car? And it is unlikely the ej25 is a ej257. There was only one JDM car that has the ej257 I beleive. The USDM stuff is what you want.

 

[ATIC...]

The original poster could even have STI internals in a RS case. How do we know this is not a ej257.

Sorry to re-hash this, but I was thinking: Is it Vishnu that makes the bolt on turbo kit for NA 251's?

If so, I'm not surprised that the engine is a 251. No one in their right mind would put a bolt on turbo kit on a 257 motor, when it's already equipped with a legit setup.

 

[yarbles]

yeah I blew my phase 2 ej25 QUICK around 9psi. dunt do it!!!!!!!! keep it low until you either swap or rebuild with some forged aluminum and powdered metal. or find out how long the top ring lands can last in the combustion chamber.

 

[Jefff]

Sorry to re-hash this, but I was thinking: Is it Vishnu that makes the bolt on turbo kit for NA 251's?

If so, I'm not surprised that the engine is a 251. No one in their right mind would put a bolt on turbo kit on a 257 motor, when it's already equipped with a legit setup.

im thinking he means ej257 shortblock with everything else a la ej251...

 

[ATIC...]

That would make more sense.

 

[danish]

Yea but it could simply be an EJ257 shortblock... alot of peeps that have a turbo SOHC have been known to build that way.

 

[Jefff]

Yea but it could simply be an EJ257 shortblock... alot of peeps that have a turbo SOHC have been known to build that way.

thats how we roll!:noes:

 

[Storm]

The original poster could even have STI internals in a RS case. How do we know this is not a ej257.

Quoted for good reason. The EJ257 internals drop right into the phase II EJ25 block. The motor very well could be essentially an EJ257 without the extra ribbing between the cylinders of the real deal.

 

[mtcs]

Yeah...
I do have the Ej257 shortblock (B25 / 701) but have phase 2 Ej251 Heads.
Pretty nasty but not sure if I should keep it sohc or go dohc. Any thoughts?

Ben

 

[Storm]

I would leave it alone. Delta can make you the cam you want if you wanna go that route. Swapping to DOHC heads will do nothing but cost you money.