Question of opinion, Blown head gasket ej20g

[pabst90-ix]

So i have a jdm ej20g swapped into a legacy that i bought 2 years ago. The head gasket blew on my friend while he was borrowing my car. I do not know if he tried driving it or starting it after, but given his experience with cars it can be assumed. Also before the head blew, the car would sputter out and revs were very inconsistent.

I believe the motor has around 120k if not more on it. When i was beginning the process of tearing down the motor, i noticed the crank pulley had also spun half way around the key.

To the point of the post, Would i be better off just buying one of the jdm ej20g long blocks off of ebay? or is it a better idea just to do the head gasket? i only ask because while i have done head gaskets before cant there be internal damage from the crank pulley spinning around the key? and the sputtering could that be an issue tied to my head gasket just being bad? then the issue of him possibly driving the car after head gasket was bad.

The question centers around if with the mileage of the motor, the other issues it had, and the possibility of unknown damage that was incurred when head blew, is it better to just do the swap again? im not sure of the engine model other than it has individual coil pack with one screw.(i was told this means something) i assume i will be finding out if its a closed deck or not when i break it down. But whats a rebuild cost vs just buying a new one?

As you can see im in the planning stage and just working out what i need to do, while having no clue and being over whelmed.

Any help or recommendations would be much appreciated.

I am planning on getting the robtune either way i go because i always felt like the rough idle and sputtering were caused by running the incorrect ecu(which is also another contributer to my lack of trust in the current block)

Any and i mean any input would be great, im trying to determine my best route to get this car back on the road. not used to dealing with FI engines

[Imprezafan93]

What all do you know about the car? Did he do a harness merge correctly? He may have swapped the ecu right? Dont know much about ej20g personally but the internet is full of info. If the crank pulley rotated past the crank key at all that's a big no no. .

Everyhinf depends on your budget. Personally i would probably want to do my own thing and know all the info but it's all relative to your funds.

[pabst90-ix]

ya i mean ive owned the car for two years now and it would just sputter and die sometimes at idle. I always assumed it was the ecu because he was running a usdm 22t ecu on it. I do think i am going to be buying a longblock though after talking with some folks about all the possible damage that may have occurred.

Thanks for your reply though. Now i just have to find a reliable person to buy the longblock from hopefully with the ecu included.

[pabst90-ix]

Any input on which model i should pick up to drop in? id rather not have to rewire the whole thing so if there are any plug and go swaps for a jdm ej20g, and which model of the ej20g i should look for?

[Legacy777]

Have you pulled the crank pulley off? It likely sheared the woodruff key or there's damage to the crank pulley/shaft. If the shaft is damaged then I'd definitely suggest getting a used motor to swap in. With the unknowns about the head gasket and work...it'd probably be easier in the long run with the swap as well.

I believe the ej20g is probably your best bet for compatibility and not rewiring things.

[pabst90-ix]

Juat got thw mptor out today and was able to get a better picture of things. The pulley seems to have been hanging on to the back end of the key which did not shear. The front portion was twisted weird. Bt im having the bottom end gone through.

I do however have one more queation, i called a place i have bought reman motors from before and they have 2002 wrx mototrs remanufactured for 1900 after core. How difficult would it be to wire this in? I aam waiting for a call from the tech to see if i can just have them reman mine. But they hve a 7yr 100k warranty and garruntee 300hp at the wheels. Good company overall ive used theyre motors in my boat and a ford ranger. Us engines in washington if anyones heard of em

And when i asled what model i should look for, i meant what year ej20g is the preffered year and out of wht car etc

Thanks for the help guys

[mike-tracy]

To put a different generation engine in, you would have to rewire the car for the engine and ecu. Easiest way (meaning you don't have your car down for a month or more) is to send your car's dash harness plus the new engine's dash harness to Iwire, and have them make a plug and play harness. That's about $700 plus mailing both harnesses. If the Wrx doesn't come with an intake manifold and all engine accessories, you'll need to get those too.

If you want to keep what you have, an 89-95 legacy or impreza ej20g is what you want. Subaru called some later engines "ej20g" as well. But they have vastly different configurations and electronics that would need rewiring for as well.

The biggest indicator for the later "ej20g" engines, is they have a coil pack and spark plug wires, from the top of the intake manifold.

[pabst90-ix]

Yep i noticted that immediately while browsing jdm import sites. Thanks im trying to figure out my move have to wait till monday to here from the engine reman place.

[pabst90-ix]

One more question. It is my understanding that i can use a ej205 usdm short block with my heads and be fine with the worong is this correct? I found one local rebuilt for 1000 and a great warranty. Also i have a certified tech coming wednesday that can help me with everything and would be willing to do any swap i wanted too. Kist though if i grab that block and jave my heads done ill be ok and hve a new block and rebuilt heads for the same price as a used motor. Is this correct or would the ej205 need different wiring than my obd1 ecu can read

[mike-tracy]

The ej205 short block will swap in, you'll want to use the thicker 89-95 ej20g head gaskets though (the ej205 head gaskets are thinner, and your ecu may or may not play nice with the bump in compression).

[pabst90-ix]

Awesome, i found a local short block for 1200 rebuilt. I can get my heads done for a good price and then im set. Wpuld the bump in compression be to severe to run 14lbs? And i was going to be buyin a robtune 550 ecu will that work?

Thanks again though mike comming through big time

[mike-tracy]

As long as that ej205 was rebuilt to stock specs (no high compression pistons)

[Alphius]

With stock EJ205 pistons and EJ205 headgaskets, you'll be at around 8.5:1 CR on EJ20G heads.
EJ205 pistons with EJ20G thick gaskets and 20G heads makes around 8.2:1 CR.

Stick with the low CR. You want the 1.3mm compressed thickness gaskets.

[pabst90-ix]

Alright, well its update time. This has become one hell of a bigger problem than i first imagined. So, disassembled the block and found a cracked cylinder. Then i took the heads and began disassembling them when i found a crack around the spark plug. So now i am starting from ground zero and i am leaning towards the sti v3 or 4. Found a few with trans ecu and harness for 2k so once i figure out if someone local can help redo the wiring im going to begin the install. Any know how hard it will be to convert the car from a jdm ej20g to run one of the sti v3-4? If i can pull it off in a day or two just might attempt it myself. I have searched all over but havent been able to find any builds similar to mine. If anyone has a link id much appreciate it.

Any how ill start a build page once its up and going.

[mike-tracy]

You are in luck, all you need to do to run a version 3 or 4 WRX or STI is put your 20g intake manifold on it along with the 20g sensors and coolant crossover pipe. That's it

[pabst90-ix]

Is the intake from the 20g going to cost me any power? if not that is the best news ive ever heard. Also the swap i found has the ecu so im going to run that instead of the rob tune,it should plug right in correct?

[mike-tracy]

Is the intake from the 20g going to cost me any power? if not that is the best news ive ever heard. Also the swap i found has the ecu so im going to run that instead of the rob tune,it should plug right in correct?

The intake from the 20g will probably flow a little worse than the ej20k one since it has 2 extra 90* bends. If you said, "I'm gonna be running 450whp with my $2500 standalone and $2000 turbo" then I'd encourage you to go with the freer flowing ej20k manifold. But if you are going to use factory turbos or similar, maxing them out to 300-350 whp, then the 20g manifold not going to hinder those modest goals.

When you say "The swap I found has the ecu," do you mean that the ej20k engine comes with an ecu? If so, it is not compatible with your car's harness at all, or even your ej20g intake manifold. I've done a bit of research on ej20k's over the years, and found that a lot of people blow their engines on the ej20k STI and even WRX ecu's. Reading between the lines, it seems Subaru tuned those ecu's closer to the ragged edge than with the ej20g ecu's. They get a bad rap for that reason. I truly believe those ecu's are tuned for better gas than we have here.

Take it for what it's worth, if you go down the ej20k electronics route, obviously there's no Robtune (though he's been promising one for like 6 years now, maybe in another 6 we'll see one? lol). The ecu's are tuned for better gas, so you need to deal with that. ESL and APEXi Power FC and a whole bunch of expensive standalones are available for the 20k, as they also are for the ej20g electronics.

[pabst90-ix]

ok, thats great to know about the manifold, but now i have way to many questions regarding my engine management setup. To answer your question, The importer is selling the engine trans ecu and harness, which is why i thought it was very convient to be able to use that ecu. However, my problem is the guy ii bought the car from was running the 20g on the 22t ecu. he merged the harnesses to run the engine. Which is why i was going to buy a rob tune when i found a motor. So now should i continue to get the rob tune to run the 20k with or should i plan on going with having to get a standalone? When it comes to engine management though my knowledge is limited at best. I would really not like to go with a standalone as the price for those is well outside of my budget. My goals are not to push the motor to its limit or anything, i want to just keep it near stock maybe squeeze a little extra out of it is all.

[mike-tracy]

Do you know if you are running an ej20g ecu already? Or the stock 22t? The robtune would work in your situation if you reuse the ej20g intake manifold and electronics. Both the ej20g and ej20k are Phase 1 DOHC engines, so from a mechanical standpoint the robtune can control either.

Compared to a stock jdm or US ecu, the robtune is a huge leap forward in tuning, and a bargain. I used one for the last 3-4 years. Only recently did I swap in the ESL live tunable board. It's a couple hundred more than the robtune, and of course you need to get it tuned $$$. Running the same engine and other components as the robtune, it's only marginally more powerful. I bought it because down the road I intend to run bigger and more powerful components than the robtune could control. And because I love to tinker with stuff

In my opinion, you don't need a standalone for what your goals are. The robtune is going keep you happy for years to come.

[pabst90-ix]

So the ecu in my car is a usdm 22t. i believe i will be getting the v4 sti swapping intake manifolds and then the rob tune to manage it. Im hoping for the best here. On receipt of the motor i will be doing head gasket, front and rear seals. Then clutch and then dropping her in. Any other recommendations on service i should do before putting it in?

[Alphius]

Timing belt

[pabst90-ix]

Ya i was planning on that and all the pulleys also. One more question, what us models can i find a 4.44 diff on? My 3.90 wont work.

[mike-tracy]

Automatic Legacy GT, Auto Outback, Auto Forester. I'm talking about late 90s to early 00's, not later turbo models.

[pabst90-ix]

Awesome thanks for everything going to be ordering it all up monday when they open. Hoping to have it ready before xmas

[pabst90-ix]

Alright well, I have ordered a stiv3 with a 4.44 transmission and matching diff for 2500 shipped from jspec. Those guys rock, hoping that i am able to get it all put together by the 1st. Now i am looking up the part numbers for the head gaskets, front and rear seals, valve cover gaskets. But i am left wondering. how would yyou guys recommend i mount the coil pack wires on the 20g intake? also i have a 22t intake the guy threw in with the car at least i belive it is a 22t which seems to have mounting points for the wire pack so im not sure if that is right or not. Here are the pics of them.

The one without the throttle body is the 20g(I hope) and the other is what i was told a 22t









Speaking with rob to work out my engine management now so hopefully i am lucky and everything goes together as planned.