legacycentral bbs

The Touring Wagon project is running. Fully rebuilt with stock internals, stock turbo and stock 2.5 DOHC heads out my 97 outback.

Im using stock EJ22T Head Gaskets. The pistons DO protrude from the block deck. About .012-.015in

These heads can be found on 97-99 Legacy 2.5GT and Outbacks also 98 2.5RS and Forrester

Disclaimer: My goal was not insane horsepower, but rather building an affordable, reliable, fun engine. Oh and I already had the Heads.

I used the 2.5 intake manifold and fuel rails, with SR20DET Purple injectors. According to the numbers these flow the same as the EJ22t injectors. And they seem to run fine.
In the pic: SR20DET, Stock Pase I 2.5, Stock EJ22t

The plugs for the SR20DET injectors are different. I just pulled the connectors out of the plugs, slid them on the pins in the injectors and filled it full of silicone. Kinda ghetto but effective.
Besides the injectors all other electronics were somewhat compatible with the NA manifold.
Alternativly, you could find some EJ20g(440cc) Injectors and rails. They bolt up perfectly and mate with the EJ25d fuel rails.

I did plug the center crankcase breather.(NOT the one connected to the PCV) As far as I can tell this was to equalize pressure between the crankcase and the heads. If you do not wish to do this you will need to tap a hole in each valve cover and put a in a 1/2in hose barb.

I modified the right head for the Coolant feed and the oil return. There were bosses for both of these so I just drilled tapped them. I used a 1/4 NPT to 1\2in Hose barb for the water and a 3/8 NPT to 5/8 hose barb for the oil.

There was an exsisting plug which can be seen as a bolt just above the water nipple. This in fact is a pluged oil galley. The turbo oil feed was gently bent to line up and the banjo bolted derectly to the existing hole.

The Turbo bracket had to be modified. I cut off the part that originally bolted to the head. This allowed clearance for the new position of the oil feed line. I also had to shim the bracket up with a few washers so that the hole that bolts to the block would line up. Alternatively, you could possibly find a bracket off of a WRX or EJ20g.

The left side head has a threaded hole in the same position that the right side coolant feed is located. This is infact part of the EGR and connected to the exhust port and should be plugged. Also the heater core return line had to be modified. This was done by cutting off the existing mounting holes and fabbing a bracket like this.

With the Timing belt installed the cam timing appeared to be off by about half a tooth. My guess is the EJ22t thicker head gaskets are responsible for this. Anyway IMHO this wasnt enough to sweat.

TIP: For anyone who hasnt worked with the DOHC heads before. Install the cam pulleys BEFORE the valve covers. There is a spot on each cam that you can put a wrench on. This makes it infinetly easier to tighten the cam pulley bolts.



Now a pic of the finished product



For those interested in the cam timing of the NA heads compared to Turbo heads Here it is.
All units in degrees

Phase I 2.5
Intake: Open 6 BTDC
Intake: Close 50 ABDC
EXhuast: Open 54 BBDC & 30 BBDC
Exhuast: Close 10 ATDC

Legacy EJ20g
Intake: Open 3 BTDC
Intake: Close 55 ABDC
Exhuast: Open 55 BBDC
Exhuast: Close 11 ATDC

USDM WRX
Intake: Open 10 BTDC
Intake: Close 50 ABDC
Exhuast: Open 53 BBDC
Exhuast: Close 7 ATDC

Oh, and I did all the work myself

What are you doing for engine management? Nice build

Thanks for explaining each bit of the plumbing and taking such good pictures!

great write up!
what is the stock turbo?

Great to see this documented. I have been trying to tell folks around here for sometime about the ease of modifying those DOHC Ej25 heads for the turbo plumbing. I am glad to see you do it.

Regarding the bracket that you had to cut, that's because it originally went to the SOHC Ej22t head. The other thing you could do is get the same bracket from a WRX or any EJ20G and it should bolt right up to the DOHC Ej25 head.

Keep us in the loop as you get this up and running...

What kind of gains would this net?

About a 20-25% increase in flow on the heads...

kidatari wrote:What are you doing for engine management?

Stock ECU

Matt Monson wrote:Regarding the bracket that you had to cut, that's because it originally went to the SOHC Ej22t head. The other thing you could do is get the same bracket from a WRX or any EJ20G and it should bolt right up to the DOHC Ej25 head.

Good Point. Though at the time it was much easier to just to mod it.

Just putting it out there for the benefit of others who may go this route down the road...

Cool thanks. I will add all additional info to the original post. This way it will be easier for people who want to do this to find the relevent info.

Matt Monson wrote:Just putting it out there for the benefit of others who may go this route down the road...

Hmmm funny matt, according to the time you posted this, I had just left your work and you havd just mentioned this..... What exactly are you getting at?

So I have a pair of these heads sitting around... and a spare 22t block....... How would this mate with a vf-29? and is there a possibility of running the turbo inlet under the intake? a wrx manifold probably wont fit since the heads are phase 1 correct?

oh and matt, I remember you saying something about being similar to early wrx heads. how do they flow compared to like NIco's new setup, or that of using newer wrx heads?

nice right up, wish i could type as good as i can build a motor. o well hahah.

anyways as long as you use the stock eletrical components from the ej22t and engien wire harness and ecu, IT'S ALIVE.

bmxpunk i think i have the biggest heads in subarus history. i had a extra 2.5l intake manifold, i used the same gaskets he is going to use. my intake manifold + the heads match the gaskets perfect from the 2.5l. when you stick them on the 2.5l there is a little meat. my dont have the meat.

bmxpunk wrote:

Matt Monson wrote:Just putting it out there for the benefit of others who may go this route down the road...

Hmmm funny matt, according to the time you posted this, I had just left your work and you havd just mentioned this..... What exactly are you getting at?

So I have a pair of these heads sitting around... and a spare 22t block....... How would this mate with a vf-29? and is there a possibility of running the turbo inlet under the intake? a wrx manifold probably wont fit since the heads are phase 1 correct?

Actually,
I think I posted it as you drove up to the shop. And I hsitate to give you guidance on this because I WANT THAT SPARE EJ22T BLOCK! ok, petulant child momment ended...

The DOHC USDM EJ25 heads flow better than EJ205 USDM WRX heads. The Ej20K heads Nico is using flow better than either of the other heads mentioned. As he said, the ports are huge! Even bigger than my RS-RA STi hand ported heads!

As for the Vf-29? That's pretty much what my original plan was when I got the turbo and v6 manifold, but substitute SOHC EJ25 heads. But's really a wash with respect to SOHC or DOHC USDM Ej25 heads. I don't think it will hold 17psi to 7000rpm like it will on a 2.0l block, but I imagine it will hold 15.5psi or so, and still give you 17psi in the middle rpms...

And if you got a '97-'98 WRX EJ20K intake manifold, it would bolt right up to USDM DOHC Ej25 heads, and yes you could use the under manifold inlet plumbing. The key is the model years. Only '97 and '98 were BOTH the inline bolt pattern and tall enough to run the inlet under.

There's a little experiement that I have always wanted to undertake. That is to try and run the turbo inlet under a '98 Ej25 intake manifold. I have never had one side by side with the Ej20K manifold to check it out. If you want to "borrow" my spare DOHC Ej25 manifold and see if you can build it into the engine, I'll let you take it when you pick up the Vf-29. If you keep it we can work out $$$ later...

Well I checked. My friend has a set of 2002 2.5 sohc heads. I was wrong. Looking at all of his crap, i get a little confused Would these still work with your "experiment" Matt. And you think these are a better head, if I recall correctly.

Oh and I am still looking for you a 22t block. I am also going to see if I can find you a whole car for cheap.

Then you would have your 22t and a body for that beatuiful RS-RA.


I think I might to need that spare 22t. My GF followed me and saw "blue sparks" coming from underneath my car when I shifted. not cool

I am a big fan of the SOHC Ej25 heads, but they don't have many of the advantages that the DOHC Ej25 offer. They do NOT have the oil and coolant galleys to easily tap like the DOHC heads. They also will not clear a factory uppipe without cutting a huge chunk out of the head. And while I don't think it's a problem, a number of guys don't like how the coolant passages line up to the EJ22T block and gasket. For ease of conversion Napphappy's approach (or Nicos) is really the best.

Or, even though it has a silly low CR, Ej20G heads from an early Liberty RS would work the same way. Basically, any of the DOHC heads from '89-98 are a fairly easy fit. After that, the cam gears become a major stumbling block since they won't work with the electronics of the early cars. To use Ej205 or Ej207 heads it gets really complicated...

Im sure the usdm 2.5 DOHC intake manifold will allow for a straight inlet turbo. I could look straight through, the only thing in the way was the evap purge soleniod and the tab that it mounts to. It may take a little modding, but what doesnt.

^^ you got to move some fuel lines. dont put that stright intake tube on its a mess. they brake easy and emagin if a vacum line breaks and you got to change something.

also the cross flow pipe is diffrent and the power steering pump is set of a little.

MAtt, life sucks. My friend with the 22t block, well he cant get his sti rods and pistons to work with his 2.5 block. If you dont have any suggestions, he's putting MY damn 2.2 in his car. trust me hes getting pissed at me for trying to talk him out of it

phase I 2.5? Won't work. Needs a phase II. Give me a call tonight...

What head gaskets are you running?

Stock EJ22t

how has this been going napphappy? i believe i will be going this route for my ej22t i have in my garage.

on that note, does anyone have any of these (ej25 phase I DOHC heads) for sale? what would be an appropriate price to spend on these? i know a couple subaru repair shops who may have em.

I will have an extra set. Possibly 2 extra sets once my build is done.

I wouldn't pay much more then about $250.

Brad

and that should be with an intake mani and all that? i guess that sounds pretty reasonable... thanks!