1997 Impreza engine in a 94 Legacy?

[MConte05]

So... I am sure there is a topic out there about this already, tried searching, couldn't get specific enough to answer the question.... Anyways:

Car is currently a 1994 Legacy Turbo, with a 1991 Legacy 2.2L Dualport NA engine and the pins swapped to run the NA ECU.

I have a lead on a cheap 1997 Impreza Sportwagon 2.2L Singleport engine that runs like a top, doesn't drip a single bit of oil, and in great shape. Compared to my leaking sieve of a Legacy engine with probably more than 200k on it, and eating more oil than fuel.

Would this be a plug and play type of swap? Or would I need to swap the entire chassis harness and engine harness because of the OBD2 that will be coming into play?

This is all going into my rally car. Looking to get a solid reliable 2.2L engine in there, mated up to a 4.11 trans with an RS LSD to make for a great beginner car, while slowly building up either another legacy from the ground up, or an impreza to make for a Open Light killer car (powerful engine, trans with diffs, etc.). The current setup is a leaky highhhhhh mileage 2.2L with a 3.9 turbo trans. It's slow, but still a hoot.

Thanks to all! Please link me to any threads of interest regarding this in case I missed them.

[entirelyturbo]

Probably the best thing for you to do would be to swap the heads off your current engine onto the 97 Impreza engine before attempting to put it in the car.

With the 97 Impreza engine assembly, you'll run into wiring issues with the throttle body and IAC valve, as that engine had a different TPS sensor and the IAC valve mounted on top of the throttle body, rather than the intake manifold. Possibly the injectors too, but I'm not sure about those.

Using the heads off your current engine means you can use your current intake manifold, which will take care of just about all your sensor/wiring issues (and you can stay OBD1)... plus you won't have to worry about swapping exhaust manifolds since you won't be using the single-port heads.

My memory is fuzzy now, but 97 was when the 2.2 got solid lifters, a higher compression ratio, and became an interference engine. Doing the head swap might lower your compression back down to 9.5:1, but should also make it a non-interference engine again. Don't hold me to that though.


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[MConte05]

Hmm, the heads though is the primary reason I want to swap. I have two bad valve guide seals and cam seals, would be cheaper to swap this engine in as a whole unit than it would be to take apart the heads, have them machined, cleaned, rebuilt, and put new headgaskets on.

So the earlier intake manifolds can't just bolt up? Was hoping that the longblock assembly could be used, assuming that just a cam sensor and crank sensor from the old engine could be used.

[Alphius]

The late intake bolts to early heads just fine (personal experience) so the early intake should just bolt up to the later heads.

All you will have to swap will be a singleport exhaust header. It will all bolt up just fine. Even the cam and crank sensors will work, but the plugs on them may be different in which case they do just swap over.

This is an easy plug and play swap using your intake manifold and a new header.

[entirelyturbo]

Yeah, if you can use your old intake manifold on the new heads, then go for it. I was under the impression that wouldn't work, but I could be wrong.

Impreza cam and crank sensors will not swap over to the old harness. The Impreza sensors just have plugs... you'll need the old Legacy sensors with the long pigtails.


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[MConte05]

So the next question is: What ECU would I use?

Would a 97 ECU run the 94 Harness? Or would I have to use the 94 ECU and hope that not much changed year-to-year regarding fueling/timing?

Ideally would like to stick with a stock ECU, but could be pressured into going with a standalone like a Megasquirt.

[mike-tracy]

Just use your stock ecu. I'm not 100% familiar with the changes between MY 97 and MY 94, but you should be able to swap all sensors and the intake manifold wiring over (or just swap your complete loaded intake manifold over as mentioned above), since the wiring harness routes differently on the 97.

Only thing I can think of is that my 97 EJ22 has EGR and my 96 ej22 didn't. If your 97 does have it, and you swap manifolds, you'll need to plug the hole in the driver side head. My 96 ECU is running the complete 97 ej22 just fine (in my 96 Legacy), it just doesn't check for EGR function. No CELs or drivability issues at all.

Either 98 or 99 was the 1st year of the Phase II ej22 which is vastly different. I imagine swapping wiring harnesses and sensors would let you still run it as normal though.

[Alphius]

The stock ECU will run the new engine just fine.

[MConte05]

Have I mentioned that I love you guys?

So now I will seriously consider this engine, hopefully can pick it up sooner rather than later (local friend of mine who has it).

So, lets throw out another question! Cams!

I have the race version of the Delta Cams for the 1991 NA EJ22. Should I be able to stick that in the 97 and get away with it? Or look into getting another set of cams from DC?

Any "good" headers for a singleport? Or do the stock ones do just fine with regards to power, no care about sound.

[mike-tracy]

I don't know the answer to the Cams question, but if no one else comments I recommend giving Deltacamshaft a call.

[Legacy777]

Just a note, I have a 97 Impreza with the 2.2. For the most part it should work to just swap over. The IAC valve is still on the intake manifold. The main difference is the TPS. If you can swap the throttle body from the legacy to the Impreza engine, you can do that and just use the Legacy engine wiring harness on the Impreza.

This would be the "least" amount of swapping stuff around. However, the only reason I'd suggest just swapping the entire 94 Legacy intake manifold would be that injectors have differe latencies and if you're using the 94 non-turbo ECU, it's going to match the injectors.

Anyway, it sounds like you've got some options.

[MConte05]

So I picked up the 97 engine, in great shape, new seals everywhere.

Has roller rockers, so the cams will swap over directly. I was about to buy new cams for the engine but Ken at Deltacam made me go home and check the rockers first as he was pretty sure I could just swap. Sure enough they were the same. Not often you have a vendor telling you to check this to save you some money. Top notch company.

Already have swapped over intake manifolds, zero problems there. As for the EGR port, anyone have a bolt size to pick up to plug it? Or do you guys just crimp the hell out of the brass line?

So far smooth sailing, will be looking to remove my old engine and trans, and putting a 1998 4.11 RS trans on the new 97 engine with a 2001 RS VLSD rear diff into my 94 Legacy shell with a 91 front end that has 2004 STI control arms and a 1995 Impreza rear subframe.... starting to wonder if I can get 10 years worth of different subaru models on this car. This is the definition of Leggos.

[Alphius]

I've seen the brass line crimped then brazed shut in a few instances. I've never had to deal with that scenario myself, so I don't know what else you could do. Maybe a pipe plug of the appropriate thread would seal that hole?

[Legacy777]

Not sure if this will be the same, but it's a start.

http://bbs.legacycentral.org/viewtopic. ... 31#p385531

[wtdash]

^Yep...M16 x 1.50 is the bolt size for the EGR port....might try an extra oil drain plug.

Also, a couple of 'gotchas' if you're unfamiliar.....Lego-ish, but not quite, as the pinion flange won't work w/your <95 drive shaft flange, and the rear axles might be different, too...can't recall from my 5-speed swap for sure.

GL,
Td

[MConte05]

Also, a couple of 'gotchas' if you're unfamiliar.....Lego-ish, but not quite, as the pinion flange won't work w/your <95 drive shaft flange, and the rear axles might be different, too...can't recall from my 5-speed swap for sure.

GL,
Td

I should still have an older WRX driveshaft sitting in my basement. But on the car right now is a 91SS LSD and I know the axles mate up to the RS VLSD rear diff no problem.

Engine/trans combo should be dropping in this weekend.