WHat phase ej25 do i have?

[bmwpride]

So im looking into building my motor,and im lost on what phase ej25 i have. I own a 1997 Legacy GT, and like i said before i have no idea what motor i have. if any of you can help that would be greatly appreciated! Thanks

[mike-tracy]

Phase I block with phase I heads, assuming it's original.

[bmwpride]

yes its original. So i guess sti rods,and pistons wont work

[mike-tracy]

yes its original. So i guess sti rods,and pistons wont work

Not without swapping to a phase II crank, along with machining the block to accept it.

[Garrison]

When did it change to phase II Mike?

[mike-tracy]

When did it change to phase II Mike?

Not sure exactly, certain cars made in 1999, and the dealer can look it up by vin. The 4 1998 ej25d's I've owned were all phase I, and my 99 SUS came with a phase II. My friend has a 99 LGT with a phase I block, however.

[Garrison]

And what, to your knowledge, is the difference between the phases of the two ej25 blocks?
Besides the crank from the (I assume) phase II sti block not fitting.

[mike-tracy]

And what, to your knowledge, is the difference between the phases of the two ej25 blocks?
Besides the crank from the (I assume) phase II sti block not fitting.

They changed the composition of the pistons for less friction, raised the compression ratio slightly (9.7:1 to 10:1 IIRC), and moved the thrust bearing to the middle for less stress (and resulting crankwalk) when using a manual gearbox. To my eyes the shortblocks look externally identical, aside from the top of the piston. You can have the case reground to accept a phase II crank for not too much. Open deck STI goodness!

I speculate that since the Impreza and Forester already received the phase II block and SOHC heads in 99 (but continued to use that same body till 01 and 02, respectively), Subaru decided to use up remaining stock of their DOHC heads on the new block since the BD/etc body was at the end of production - no need to rewire the car.

[Garrison]

And the whole sti A and B piston thing? What's the difference when inserting into the ej25d?

And are you saying that there are phase II, ej25 dohc besides the sti block?

[mike-tracy]

And the whole sti A and B piston thing? What's the difference when inserting into the ej25d?

The A, B and C pistons refer to their diameter. once the sleeves are in the block, they are fitted with one of 3 size pistons that fall within a certain piston to wall clearance. This clearance is within the tens of thousandths. All blocks that have excessive gap that even a "c" piston won't fit properly are discarded.


And are you saying that there are phase II, ej25 dohc besides the sti block?
The DOHC part doesn't matter for the shortblock. All EJ25 blocks are phase II besides the 96 through some 99 ej25d's, at least in the states.

If you are trying to build up an open deck ej25x block with STI crank, rods and pistons then you should have the bare block inspected by a competent machine shop as several higher mileage examples (of open deck blocks) that I've seen came back out of round. Fine to use for n/a purposes but would fail if turbocharged.

[Garrison]

You hit the nail on the head. I'm going to wait until my engine blows itself up and then replace with sti internal goodness. Thank you very much for such informative answers.

[jewbaru]

awesome :smt023

edit: Garrison, please tell me thats a pancake on that rabbits head :lol:

[bmwpride]

where is the thrust bearing in a phase 1 ej25d

[Grafton]

#3

[bmwpride]

so anything that would be phase two would have it in #5 correct? Also when just looking at the crank do you count the journals from the back to the front(sitting in car) or front to the back( from popping the hood)