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Hi,

This thread has been started to fill a gap missing since the old board. I am going to cover the basics of fitting the EJ series of motors into the older MY and L series Subarus. This is by no means a complete guide, it is more of an overview of the project.

Newbies should read through all this info before asking questions as starting a new thread. While we really do love to help, getting asked the same questions over and over is a little tiresome.

First of all I'd like to clarify for those out there what each of these is. An MY is a Subaru originally fitted with an EA71 or EA81 motor, this includes all coupes, sedans and wagons from 1979-84 and all second generation Brumbys (1980 on). An L series is a sedan or wagon produced between 1985 and 1994. There were other body styles produced, but we are focussing on the Australian models here.

Secondly I'd like to distinguish the variants of the EJ series of motors. They are a wide and varied series, ranging from the 1.5 litre EJ15 up to the 2.5 litre EJ25. There are multipoint injection motors (MPFI) and single point injection motors (SPFI). There are single overhead cam motors (SOHC) and double overhead cam motors (DOHC). There are also turbocharged motors, in Australia and Japan these are all DOHC. These are often reffered to as EJ20T's, in actual fact this motor doesn't exist. The first EJ20 turbo motor was the EJ20G, and there have been many model codes since, such as the EJ20K, EJ20R, the EJ207 and so on and so forth. There are minor differences when converting too, Subaru have fitted many different heads, manifolds and turbos to each model.

Also, I am assuming in this guide the use of a manual gearbox. I have no experience with EJ automatic gearboxes, so I'll leave that to someone more in the know.

The Basics of fitting an SOHC EJ motor to an MY:

This process is rather straight forward. Any motor up to the EJ22 can be fitted without modification to the chassis rails, the only potentially structural modification to the body would be the slotting of the holes in the engine crossmember where the mounting studs slip through. I beleive to fit the EJ25 motor there would need to be major modification to the chassis rails, more so than the turbo motor (see below).
The engine crossmember needs to be spaced downwards about an inch and the steering linkage modified to suit for bonnet clearance. This is not necessary on a lifted vehicle. This will make your camber more negative and flatten your front CV angles.
The radiator outlets will need to be modified to suit the larger hose size, but the radiator should be OK for cooling capacity.
The exhaust will need to be custom built, a good setup is to use the factory EJ exhaust headers and then custom pipes from the centre back. You could also modify the exhaust headers to fit your standard system.
The best way to do the wiring is to take the entire EJ engine loom and trim it down to suit your needs. You'll need to keep all the engine sensors and devices, wire up a check engine light and spider the harness into your vehicle. Most find this to be the most difficult point.
If fitting the matching EJ gearbox, you will need to use custom inner CV joints to mate to the larger splines on the EJ gearbox. The gear linkages will need to be shortened slightly to fit in the right spot. Some people have opted to use an EA gearbox, this requires an adaptor plate and slotting of the EA flywheel to mate to the boss on the back of the EJ crank.
If using an EJ AWD gearbox the tailshaft must be lengthened 120mm to accomodate the shorter length of the box.
A matching rear differential must be used.
The fuel system needs to be brought up to EFI spec. Most people use a Bosch fuel pump from a VL Turbo in conjunction with a surge tank. A return line must also be plumbed through the vehicle.


The Basics of fitting a DOHC EJ motor to an MY:

The process is mainly the same as for the SOHC, but with attention to the following points:
The chassis rails will need to be cut & reshaped to clear the timing covers.
If fitting the turbo motor also, the crossmember must be modified to suit the up-pipe on the turbo. Alternatively a turbo crossmember can be used, provided it is from the same model as the project.
Realistically the only gearbox that should be used is the matching turbo gearbox. These use a much stronger pull-type clutch.

The Basics of fitting an SOHC or DOHC EJ motor to an L series:

The process is mainly the same as MY, but with attention to the following points:
The engine mounts will need to be spaced upwards with washers, the L series has a slightly different angle on its engine crossmember than an MY.
The entire EJ series of motors can clear the chassis rails. No modification needed.
There is a difference with the tailshaft in an L series. I have heard it needs to be lengthened 70mm, although I can't confirm this at the moment.

I'm sure I've missed some things, and if you see any errors please point them out.

L series with EJ20T
Tailshaft length needs to be shortened, not lengthened.
I can't confirm by how much, as I bought my car with this already done.
Gearshift linkages need to be shortened by the corresponding amount.

EJ rear diff bolts directly into L series. Rear driveshafts need to be changed by using L series inner CV joints onto either end of the shaft.
This only applies if you're using the early rear diffs which have the male splines on the diff.
My car came with the other type of diff where the mlae spline was on the shaft. This perpectually spat the shaft out of the CV under load due to the shafts not being long enough. I swapped the diff for a Liberty RS Turbo version.

The stay from the top of the gearbox back to the firewall needs to be changed from the L series to the matching shorter one from the gearbox.

wagonist wrote:L series with EJ20T
Tailshaft length needs to be shortened, not lengthened.

Sorry but I just got my gearbox and engine in and the tail shaft needs to be lengthened. Mine is an auto L series tail shaft with a 4.11 RS legacy gearbox.

The auto L series box is a lot longer than the manual one, so therefore, the tailshaft is shorter.

What kind of mods need doing to a L series crossmember for a WRX up-pipe????

If you've got an L series turbo crossmember, then none. If not, then you need to cut out a section to weld in a curved part where the turbo up-pipe goes.
Easiest is to use the turbo crossmember, just got to find one first.

Thanx, I think cut and weld will be easier than trying to find a turbo one...

BTW how much do I have to cut out of the crossmember? Will it make an engineer cry?

You don't ned to cut much out at all. I just did mine for the ute this arvo. Easiest way is to get a bit of 3 or 3.5 inch pipe from an exhaust shop. You only need about 130mm of it.

When you look at the cross member from the front you see where it bolts to the chassis then starts to roll down hill towards the ebgine mounting holes. It is just inside where it starts to roll down that you need your first cut. Cut it down to about 5mm above the lip at the front. Make the pipe you weld in there sit at about a 50 degree angle. Weld it right around and then smooth off with a grinder.

If I can get some one to lend me thier digi camera I will get some pics of it. Along with pics of where to cut and how much to fit the quad cam in the engine bay.

What gearbox crossmember are you using in an MY to yake an AWD eJ manual gearbox?

Entirely custom built, basically a piece of box tube running from one side to the other with a flat plate welded to it to space out to the gearbox mounts.

I wouldn't do it that way again... maybe someone else can share what they do... Brett?

The gearbox crossmember for my L series is completely custom as well.

Use the original front member. The rear one has een made out of a bit of flat plate (though I'd like to change it as it only uses 2 of the 4 available holes & I'd like to reuse the original rubber mounts.
Then using the original EJ rear mounts, a piece of flat plate wider than the bolt holes is then welded to the front member & curved around the rear of the box to meet the rear flat plate.
The holes for the gearbox mount are slotted.

I'd rather the pieces were only bent & bolted together rather than edge welded.
Any thoughts on this?

Anyone got an idea what it would cost to drop a EJ motor in by a professional mechanic. It would be into a brumby. I am starting to get keen on a better engine as the 1.8 is gettin on in age and wouldn't mind a bit of extra power

I've heard prices of around the $8000 and above mark, but bear in mind 99.9% of mechanics out there don't have the will or the skill for this conversion. You'd want to find someone who's done this swap several times before.

What length tailshaft do you use when using the EJ awd gearbox?
Jeff

Depends on the vehicle, but for an MY:

tim_81coupe wrote: If using an EJ AWD gearbox the tailshaft must be lengthened 120mm to accomodate the shorter length of the box.

Someone else may be able to answer for an L series... AndrewT?

Thanks Tim it is an MY i will be doing

EJ throttle cable will hook up to the EA accel pedal okay?

Sort of. You simply put the ball on the end of the throttle cable in to the place where the my goes and then close it up a touch with some pliers. Don't crimp it up tight though as you will put stress on the end of the cable.

stinky wrote:EJ throttle cable will hook up to the EA accel pedal okay?

The EJ cable has a funky firewall connector thingamy too. Pull the brake booster off so you can get to the hole in the firewall to file it out. I used a dremel on both of mine to make it fit. I did a way better job on the wagon than the RX but hey, that's conversions...

Yeah I had to butcher that little plastic thing too, and from memory it's now on the wrong side of the firewall with a hose clamp retaining it. 3 years on and still holding.

My next EJ20 turbo conversion is going to be so much better.