For all those EJ22 swaps looking for more power.

[Subafreak]

Im sure most of you have heard of the EJ25 block with EJ22 heads hybrid motor.

 

If you have a EJ22 swap already you've got all the hard work done, and i can tell you it is a worth wile swap. It gives you the power of the EJ22t with the down low tourqe you need for off-road and non of the complications or possible failiers of a turbo swap.

 

Now EJ25 blocks have are not known as a great block, between there piston slap and a strange tendancy to throw a rod thru the block. I dont know why i have seen so many with rods sticking out but i assume it has to do with poor maintinence. The piston slap is a known issue but is ussually with in normal limits and can always be made better with the updated coated pistons.

 

The EJ25 block we put in the monster Legacy had stuck piston rings from lack of oil changes. All we had to do was clean the ring grooves out and replace the rings and now it sounds and runs great.

 

Thw simple build is to use an EJ25 series I block, with the DOHC heads on it. Then you get the headgaskets for that block and match them up to your EJ22 heads and drill the coolant passages from the headgasket into the heads. Then you will need to carefully drill the two small holes through the headgasket for the exaust valve coolant port for the EJ22 heads. Bolt it all together with your EJ22 acceroies and drop it back in.

 

I wish i had taken a couple of pics when we were doing this, but trust me you will have so much more crawling power and acceleration it will feel like you just dropped in a big block.

[Pooparu]

I've been wanting to do this with my ej swapped hatch. I also wanted to get the EJ22 heads ported and polished too, and get some aggressive street cams. I was also thinking about using ARP studs for the heads so I can really get them tighten down.

 

My friend was thinking with that motor in my hatch I'd have a great power to weight ratio (It may be as quick as a 2002 stock WRX).

 

It'd be great if someone could do a good write up on this build with photos. If no one gets to it before I do my build I'll try and put something together.

 

Thanks for the post.

[idosubaru]

nice info, i've seen folks ask about this so this should help them in the future.

 

i don't think it's poor maintenance, EJ25's just have far more issues holding their bottom ends together than previous subaru's. i've also seen quite a few with bearing noises.

 

i'd turbo an EJ22 with low boost. more power, can keep it non interference if you want, and more reliable than an EJ25, without the custom head and gasket drilling.

 

they do well with low boost. but of course turbo sucks for off road right?

[iluvdrt]

You know the guys over on BBs. Legacycentral.org are all EJ22 Gurus. They would be able to help a lot with these builds.

 

I have a P1 EJ25 in my 98 LGT wagon. It has 220,000 miles on the stock bottom end. I auto-x it, and generally beat the poo out of it. It has been a great motor (for the past 70k miles Ive owned it), and wouldnt worry about it blowing up. The reason they break rods is that the rods are weaker than most and people try to boost them or use other power adders (nitrous). In NA form mine has been a great high revving motor.

[idosubaru]

statistics don't bother many people, so this information is useless to some, but helpful to others.

 

power and abuse don't cause the higher rates of EJ25 bottom end failures. daily driven EJ25's are having bottom end failure. way more than EJ22's. which is odd considering how many older EJ22's there are and how many EJ25's come in higher end, more expensive, and usually better maintained vehicles.

 

EJ22's and EJ18's actually handle low boost very well (if you maintain your coolant temps and EGT's).

 

that yours hasn't experienced any issues doesn't mean none do or that yours didn't in it's first 150k. plenty of info here or on any search engine, or any local classifieds in areas with lots of subarus "blown engine Subaru for sale", if you want to see the trend.

[Subafreak]

I admit i was a bit sceptical about replacing the bullet proof EJ22 with a 2.5L given there reputation. But the guy i work with (the shop forman) who has been working on and expirementing with Subarus for 30 years praised this engine configuration so i took the risk and am loving it so far.

 

I suppose if you wanted to go crazy you could upgrade the rods and pistons and maybe even use an STI block, but this build is all about low cost easy to resourse parts. If it was about the most bad a$$ motor swap for off-road i would drop in a turboed 3.6L

 

Turbos arn't bad for off-road, i had a turboed EJ22 in my Loyal and it was ok, better on road but most of that cars limit off-road was due to gearing anyway, and that motor ran great untill the fuel pump got weak and fried cyl #3.

 

My motivation on going with the EJ22/25 hybrid was the fact that the car is a Legacy so it's already wired for the EJ22, I dont have to worry about leaning the motor out of over boosting it, and basicly all i was doing was sticking a 2.5L block between everything that was already there. Seems easy and worry free and low buget, and everthing thats been done to this car has been kept to the low buget theory. If this thing ends up left out in the woods for a couple days i dont want $10K worth of parts sitting out there.

 

On the other ideas of porting the heads or installing big cams. Well porting the heads would probly be a good idea but the whole reason this motor works the way it does is becouse the cams. It's still a non-interferance motor, most of it's high compression attitued and low end tourqe are becouse of the cams that are in the heads. The cams are operating for a 2.2L doing everything faster than the 2.5L bolck. Valves close sooner building more cyl pressure, between that and the cyl head pent roof angles makes this motor do what it does.

[Pooparu]

On the other ideas of porting the heads or installing big cams. Well porting the heads would probly be a good idea but the whole reason this motor works the way it does is becouse the cams. It's still a non-interferance motor, most of it's high compression attitued and low end tourqe are becouse of the cams that are in the heads. The cams are operating for a 2.2L doing everything faster than the 2.5L bolck. Valves close sooner building more cyl pressure, between that and the cyl head pent roof angles makes this motor do what it does.

 

Oh, good to know.

[torxxx]

ty for this info.

Funny yesterday a friend asked me about making a more powerful ej22.. and I mentioned this but wasnt too sure cuz I hadnt heard about it in a long time.

I think im going to track down the parts and start building one to put on my 86 lifted wagon

[Wirebrush]

I'm thinking of going this route as well, just because the 2.5's seem to be more available around here and I can get 2.2 heads and intake from the local wrecking yard for not too much dough. With big tires the extra low end torque would be very helpful both off road and on the highway.

[NoahDL88]

Bump, the info is good and it seems a lot of people are thinking about this right now.

[cobcob]

Another alternative (albeit with more work involved and more geared to a street car rather than a crawler) is to put EJ25 heads on your EJ22 block. This will effectively drop your compression and allow you to run some boost quite happily.

[tricked919]

I've got an EJ25 motor that you could eat off of but has a rod knock. Heads just got re-worked less than 1000 miles ago and are in awesome condition. ...in case anyone is interested to try this out. I've lost my appetite for the 25

[Xise]

I always thought the NA ej25 blocks were bad for turbo apps due to the higher compression and tendency to detonate because of the high comp + boost.....does having the EJ22T heads somehow bump compression down to an acceptable level for turbo apps?? because that would just be awesome, as I know of a set o ej22t heads bolted sill to the exhaust mani,turbo and up pipe from a leggy turbo...if that bolts right up to an ej25 motor with the proper specs for "safe" boost on i'll slap that right on my RS lol.....just ECU would be the problem. If I am correct it is NOWHERE NEAR that easy to do reliably.

 

anyone test the ej25 with the 22t heads?? i would love to see proof of this

 

If I could find everything I needed the ideal setup I think of would be;

 

EJ22T block

EJ25 phase 2 crank

EJ257 connecting rods and pistons

EJ20 wrx heads usdm

 

from what I understand and research I have done the heads bolt up with no drilling of any coolant passage and strokes the engine without any boring or using oversized pistons/rings/bearings to 2.3...I am sure there is a thread about it on bbs.legacycentral.org. I imagine this combo would be quite monstrous for boosting potential.

Edited October 6, 2010 by Xise

[GeneralDisorder]

EJ22T heads are no different from plain old EJ22E heads except they have smaller valves .

 

They are a total joke of a head.

 

They will raise the compression just like the NA EJ22 heads will. It's the pistons that change the comp. ratio not the heads on the 22T.

 

The heads are worthless. Worse than worthless actually since EJ22E heads would be an improvement.

 

Yes - the 2.35 stroker is a monster engine. But it's closed deck makes it difficult to keep cool under high power situations and with the advent of the 257 it's not really a popular block anymore. If you already have one (like me) then it's a nice starting point. But these days most people go with the 257 due to availibility, larger displacement, better cooling, and ability to handle basically just as much power.

 

GD

Edited October 6, 2010 by GeneralDisorder

[1982gl4]

I've been wanting to do this with my ej swapped hatch. I also wanted to get the EJ22 heads ported and polished too, and get some aggressive street cams. I was also thinking about using ARP studs for the heads so I can really get them tighten down.

 

My friend was thinking with that motor in my hatch I'd have a great power to weight ratio (It may be as quick as a 2002 stock WRX).

 

It'd be great if someone could do a good write up on this build with photos. If no one gets to it before I do my build I'll try and put something together.

 

Thanks for the post.

 

First of all I have seen your hatch and that thing is sweet!!!! It's been quite an inspiration for my brat project! I'm actually starting one of these builds this week in my automotive engines class! I have my 2.5 block which is getting all new bearings, rings, gaskets, ect... I got given a 1997 brighton 1.8 so I'm using the heads off from that from what I've read they're the same?? I'm using a Lego five speed behind it I figured that the ea81 trans would turn to shrapnel with that in front of it, plus I need another gear bad! I'll try to take pictures as I go along!

Edited October 6, 2010 by 1982gl4

[idosubaru]

nice bump noahdl.

Yes - the 2.35 stroker is a monster engine.

woah, the displacement drops that much just by swapping heads? wow, would have never guessed it. that's the figures for a 2.5 block and EJ22 heads?

 

I've currently got in my garage:

Phase I 1998 EJ25

1997 single port EJ22 heads and manifold

 

So I've got everything needed already on the ground.

The 97 EJ22 is one of those rare ones without EGR though but doesn't matter in this state luckily.

Edited October 6, 2010 by grossgary

[WJM]

nice bump noahdl.

woah, the displacement drops that much just by swapping heads? wow, would have never guessed it. that's the figures for a 2.5 block and EJ22 heads?

 

No.

 

Xise talked of putting an EJ25# crank into an EJ22#. That changes the stroke from 75mm to 79mm. Bore stays at 96.9mm thus increasing the displacement.

 

Heads to not affect static displacement. They do affect VE/dynamic displacement due to flow rates.

 

The 2.35 isnt that great (compared to an OTS EJ255/EJ257) unless you are stuck in some kind of weirdo rules/classing that you cant use anything other than an EJ22# block.

 

If you are going to bore/stroke something, get the EJ25# and the 2.8L kit and keep it below 7100rpm.

[WJM]

I always thought the NA ej25 blocks were bad for turbo apps due to the higher compression and tendency to detonate because of the high comp + boost.....does having the EJ22T heads somehow bump compression down to an acceptable level for turbo apps?? because that would just be awesome, as I know of a set o ej22t heads bolted sill to the exhaust mani,turbo and up pipe from a leggy turbo...if that bolts right up to an ej25 motor with the proper specs for "safe" boost on i'll slap that right on my RS lol.....just ECU would be the problem. If I am correct it is NOWHERE NEAR that easy to do reliably.

 

anyone test the ej25 with the 22t heads?? i would love to see proof of this

 

If I could find everything I needed the ideal setup I think of would be;

 

EJ22T block

EJ25 phase 2 crank

EJ257 connecting rods and pistons

EJ20 wrx heads usdm

 

from what I understand and research I have done the heads bolt up with no drilling of any coolant passage and strokes the engine without any boring or using oversized pistons/rings/bearings to 2.3...I am sure there is a thread about it on bbs.legacycentral.org. I imagine this combo would be quite monstrous for boosting potential.

 

You cant put the Phase 2 crank in a Phase 1 block w/out machine work. Use the 1996~1998.0 EJ25D crank, its phase 1 so it drops in w/out issue. 1998 was a changeover year, most 1998.5 and most all of the 1999 EJ25D's were Phase 2 with the #5 location thrust bearing. All EJ251/252/253's are Phase 2 with #5 location.

 

The BEST thing to do is just put some 8.2:1 OTS (Off The Shelf) drop in CP pistons, stock STI rods in your RS engine with a bolt on turbo kit and a Hal-Tec, Hydra or AEM standalone EMS. Injectors, fuel pump, 3bar MAP sensor and you'll be good to go. Next, you'll need a transmission because you'll break it at about 400~500tq unless you abuse it and you've probably broken it already with the N/A engine.

 

I'm not sure, so you'd have to check for yourself, the Phase 1 EJ25D crank may have different journal sizing for the rods. If thats the case, you'll need a different rod option or machine the block for #5 location.

 

Do make sure to use the 11044AA642 headgaskets.

[zyewdall]

I just had to laugh when I saw the title for this... coming more from the old gen side, an EJ22 swap means going from about 85HP to at least 140HP... a stock EJ22 has so much more power (than an EA82) that needing more power out of it is not usually the problem.

[bstone]

Mildly off topic post:

 

I can take an EJ25 block and put on EJ22 cylinder heads? Will it just work or is something special needed?

 

I have an EJ25 motor sitting in the basement with a blown HG. Going to rebuild it one of these days.

[ShawnW]

It will work, you have to make the adjustments in the initial post of this thread.

[bstone]

It will work, you have to make the adjustments in the initial post of this thread.

 

Cool. Other than less power (fine with me, I assume that would mean more MPG, which is what I love) what else might I notice?

[NoahDL88]

Mildly off topic post:

 

 

really?

 

Really?

 

I don't mean to be an rump roast but that is exactly what this whole thread is about Specifically the first post.

[WJM]

Mildly off topic post:

 

I can take an EJ25 block and put on EJ22 cylinder heads? Will it just work or is something special needed?

 

I have an EJ25 motor sitting in the basement with a blown HG. Going to rebuild it one of these days.

 

If you have the EJ25 heads, use those.

 

Otherwise, mod the headgasket. You will see an increase in compression ratio. Not really much power gain otherwise. Lots of people have done that swap before.

 

Otherwise to the otherwise...everything bolts on.

[ShawnW]

Except 4 cam engines don't fit in the frame rails of an ea81 body which is part of what was being discussed in the thread.

 

For anybody with a Legacy or Impreza body nevermind that, it will fit.