I have a 2002 sti which has started knocking. i have the chance of a working Ej25(not EJ257) 2.5 complete bottom end. is it worth putting it in my sti with the rest of my sti bits??? not sure where the EJ25 came out of?? what are the downfalls of fitting it?
thanks

 

Good chance it would destroy itself in a very short time - IIRC, the Phase 2 EJ 25 is an open deck, Normally Aspirated, SOHC engine with a CR of 10:1.
Piston to valve clearance could be an issue due to the higher lift / duration and rpm of the your STi cams/valvetrain and certainly the high CR would det the pistons and knock the bottom end out.


Mick

 

cheers mick,
a bit more background info.
the EJ25 bottom end is already in a 2002 wrx with as far as i know the wrx heads and all ancillaries. i have just bought the 2002 wrx with the EJ25 bottom end being in the wrx for 10k and seems to be running fine. The owner said he had it fitted when his wrx engine gave up and was told it was out of a 2007 sti. my plan was to use the EJ25 bottom end in my sti. is there any way of visually telling which version it is or if its really an sti bottom end? thanks

 

EJ 257 semi closed deck block :











Mick

 

cheers merlin, but the block is still in the car running so i cant see much.
If it was anything else but a EJ257 would it run for 10k with wrx heads, turbo and ancilleries? is the EJ257 the only one with twin breathers and block casing stiffeners?

 

just checked and mine has got twin breathers and casing stiffeners. does that mean its a EJ257? or can it be any other block? cheers

 

The only other twin breather blocks are EJ 207 ( Version 7 STi ) and the EJ 22 ( 22B ) but will be marked EJ 20 and EJ 22 respectively just behind the oil pressure switch.
Neither of these have the zig zag casting stiffener's on the block.
Hope this helps.

Mick

 

many thanks merlin. muchly apprieciated. Seems like this really is a sti 2.5 engine after all. any idea how much the wrx heads would be holding it back compaired to sti heads? and would the sti heads off my 2002 sti be much different to the original sti heads off the 2.5?? if i were to fit them? cheers