I know this is an Impreza forum, but there isn't an NA forum in Legacy General, so....
I need some help and some insight.

The current situation:
1997 Legacy Outback
EJ25 DOHC NA 60,000mi (car's second engine)

Goal:
Bulletproof NA engine capable of light towing, rallycross

Parts Budget:
$3000

Route 1:
Eagle Rods (or Outback Rods www.outbackmotors.com)
Wiseco Pistons
Cometic headgaskets

Route 2:
STi shortblock (will this even mate to my existing tranny?)
my existing heads

Route 3:
???

I also plan to upgrade the cooling system with a better radiator and possibly an oil cooler. Budget above is strictly for the engine.

I'd like the end product to be as trouble-free as possible, while getting the most bang for my buck. 'Maximum reliable power' , I guess you could say.
In fact, I'd be happy if it had just as much power as it has now, but was completely bulletproof.

Any insight you could give my floundering mind would be greatly appreciated.

thank you

 

I'm wondering if you have the same block design as the STi, reason i say that, is (atleast recently) all the Imp's have had SOHC instead of DOHC. Other than that i honestly have no clue.

 

I have the 2.5L DOHC non-turbo that was available in US Legacy's and some Imprezas between 1996 and 1999, I think. After that, they began phasing out the DOHC in favor of the SOHC (more reliable, with less moving parts, I guess). Don't think they started using DOHC on a 2.5L again till our current STi. My understanding is that there are significant differences between the two 2.5L DOHC designs. What I'm not clear on is if those differences will affect compatibility with my Legacy's older parts (like the tranny).

 

you would need high comp pistons if you wanted to run it N/A.

 

The '98 2.5RS's are DOHC. I think all the other 2.5RS's are SOHC. My '97 L is a SOHC and so are the newer years as well.

 

Your 1997 L is a 2.2...all 2.5s before 1999 were DOHC