so, ive got an ej25 from a 96 or 97 outback wagon, and i have the option to get ej20 heads from a 96 wrx sti from japan. apparently, the same engine as a 2002 sti, but different body? i dont know, you tell me....

but what i want to know is, im rebuilding this ej25 to put in my vw vanagon... im doing all bearings and seals, so heads are coming off anyways, can i bolt on the ej20 heads and go? anything need to be modified? ive heard about performance gains, what should i expect??

figured id come here to ask scooby pros as aposed to vw ones. thanks

 

Hi there

EJ25 has been mostly used on US cars,on UK cars they come after 2005(Hawkeye models),JDM never used EJ25(although only JDM hatch WRX A-Line have 2.5L/EJ25),JDM or UK cars used EJ205(Open deck block) or EJ207(semi closed deck block)

2002 STI should have EJ207 not EJ25,heads on STI(V7 or if you prefer on Bugeye onwards 00-01) are AVCS,96 WRX STi should be V4-V5 and those heads are not AVCS and not been used on 2002 STi although in US has been available in this date think RS model,but maybe I'm wrong and someone will correct me soon

If you will be putting EJ25 to yours I would go add there forged rods and better pistons,standard pistons are poor and I would replace them,plus I would add too at least ARP headstuds and use Subaru MLS Headgasket or Cosworth depends on budget

No you can't bolt EJ20 heads on EJ25 without the matching them to EJ25,any good machine shop can do this and really I wouldn't bolt them without the doing this

Performance gain,do you will be running turbo or just as NA ?

Thanks,Jura

 

keeping it na. dont want to destroy the auto trans on my vw. planing on rebuilding the tranny too, to survive the added torque and hp.

stock 2.1l ohv vw is 95hp.... at the crank. and its trying to push a 4000lbs+ 4 people and a weeks worth of camping supply. grossly underpowered. driving to Vancouver, ive been passed by fully loaded semi trucks, with there hazards on. hence my plan for a DOHC EJ25 conversion!

its going to cost me in excess of 3000 bucks to find a kit for putting the scooby in my bus, so im not looking to blow a lot of money that i dont have to. the heads for the ej20 that are sitting on m bench, kid wants 750 bucks. ive already got a full EJ25. if it cost $100 to machine heads to make them fit, and it doubled mt fuel millage, or hp, i might go for it, but if its just to get an extra 20hp, than i dont think its of value to me. (btw my estimated machining cost is a dream)

any hoo... anymore input on this?

 

I wouldn't fit turbo heads to a N/A engine as the cams/compression ratios will be all wrong. Get a set of N/A 2.5 heads

 

I'd just use the heads you already have and put the extra cash into your engine, forged pistons, and new crank etc, dependant on condition of your existing heads possibly valves and retainers but definitely some new valve stem oil seals, It's a thousand bucks that's better spent elsewhere. IMO

You'll probably get a similar result from some mild porting to improve gas flow as the factory port matching isn't the best.