STI heads on an EJ20T
 

We have an EJ20T from an 04 WRX with two cracked heads. Having trouble finding some good used heads for it. I have a line on an STI motor with a bad lower end, don't know the condition of the lower unit yet. I have two questions, will the heads from the 2.5 motor work on the EJ20? If so what else do we need to do to make the swap? If the lower unit is rebuildable, can we slip the whole STI motor into the WRX without to much modification?

I won't have info on the STI motor (year, condition etc.) until tomorrow (16th) but I want to know what possible can of worms I might be opening.

Where are the cracks located?
How many miles on the 2.0 liter?

Both heads have multiple cracks around the spark plug holes...machine shop said they were toast...probably overheating...85K on the engine. We bought the car cheap knowing the motor was bad, it also needs some very minor body work. New heads will be about $2000 by the time all is said and done.

....The STi long block...12k miles and a spun bearing...but I can pick it up cheap... what else will I need to get, I am assuming new injectors, ECU but will it bolt up to the transmission housing & turbo?

If you are great with wiring, get the STi heads and have fun.
If not, you can run the WRX cams & sprockets in the STi heads.
You'll have to use all of the AVCS plumbing.

I am afraid I am not "great with wiring" ....so can I swap out the WRX cams and sprockets and then just use them on the 2.0 block like regular heads and ignore the active valve control?

What about a motor swap? If I just rebuild the lower end of the STi can I drop it in (with appropriate electronic upgrades)

I got the motor today, it is an EJ25 out of an 08 STi. with only about 12k on the motor. What we would like to do is drop this one in reusing the EJ20 /turbo/manifold and existing ECU. Which means the AVCS will not be used. Can we just plumb this up and ignor the electronic inputs on the AVCS? Any help is appreciated.

[quote=PSUDad;2776866]I got the motor today, it is an EJ25 out of an 08 STi. with only about 12k on the motor. What we would like to do is drop this one in reusing the EJ20 /turbo/manifold and existing ECU. Which means the AVCS will not be used. Can we just plumb this up and ignor the electronic inputs on the AVCS? Any help is appreciated.[/quote]

very interested to see how this frankenstein turns out.

LOL, that is what I am afraid off.... :) I have been told this has been done before...but???? So far all I have invested is $3K in the car and $250 in the motor so I have some room to manuver. Taking apart the motor this weekend to find out what parts are bad.

Take lift


Take pictures...lots of pictures.

Short story....swap has been done but involves way more than what we want to tackle. Specific tuning is critical and no one near us will do it. So we are saving the 2.5 for a full swap later. We will try to gather the rest of the parts on the cheap (and a 6 speed tranny) but need to get the car running soon so we are back to finding some heads for the EJ20T. Any suggestions as to a source for new or rebuilt heads?