ej22 with ej25 heads?

[98legacygt22]

Looking to start building a motor that I can run at least 13-15lbs of boost on which may seem high to you but I dont really beat on my car Id just daily drive it but have that extra power. I have read that the ej22 phase 1 block will accept ej25 DOHC heads and that its pretty good for running boost on but I have also heard that the phase 1 EJ22 can have the SOHC 2.5 phase 2 heads put on. Im not sure if this should be in a different section but what heads should I look for and what year and model. I'd be getting the car professionally tuned and also using EJ22T pistons. I tried to search but didnt come up with much of an answer. Any info is greatly appreciated. This question probably comes up all the time, so sorry in advance.

[mike-tracy]

I feel that this post is a better fit in the "Swaps and Conversions" forum.

Hi 98legacygt22, everything you've said so far is possible, but I feel that this is a more expensive path to power than starting with a USDM WRX engine swap. Less reliable and less capable for tuning VS OBD-II opensource as well (unless you spring for a Standalone $$). Having said that, you would be spreading that cost over time VS the rather big upfront cost of sourcing a complete EJ205, wiring harness & ecu, and wire merge. Your path appeals to me because I'm a DIY'er, but realistically you'll be spending thousands on an old block with old pistons, and some sort of piggyback or standalone, and jerry rigged wiring and intake. There is a good chance it won't pass emissions either.

If you can do all the work, such as RNR'ing the block and drilling and tapping the heads, and nothing needs a significant machine work, and all your parts work perfectly the first time, no issues with electronics, etc then you can prob pull this off for under a grand, minus piggyback/standalone and tuning.

I invite people with different opinions to post, so I/we don't come off like a bunch of assholes, lol.

[lord flashheart]

oh boy here we go.
lol
so what your research is correct, but i use that term in the loosest way possible.
i will try and make this quick.
1) how you drive your car doesnt mean you can run more boost. everything has a limit.
2) for the most part, you can put just about any EJ series heads on any EJ block. but bolting on the block isnt the problem.
the problems you run into is the intake manifold bolt paterns are different. so if you change heads, you gotta change manifolds.
also you are over looking the compression ratios changing. if you use heads except the phase 1 ej22 heads with the EJ22T pistons the odds are the compression ratio will be... well... dizzmal.
3) engines are air pumps and horsepower is the bi-product. so.. you need X amount of CFM of air to make X amount of power. its physics, you cant cheat that. and because you need to match fuel to that air you can calculate how much fuel is required to make X amount of power. so, that being said, you will be needing bigger injectors achive 15lbs of boost and realilistically if you dont figure out your compression ratio, you wont be pushing 15lbs of boost on a 9 to 1 engine on pump gas.
usually i recommend the DIY route to alot of people. however i dont think its ideal for you.

here is what we need to know from you before i can even start to point you in the right direction.
1) what is your budget, how much is the max u are willing to spend.
2) what is your goal for the car
3) how much power do you want to make
4) what kind of experience do u have.

sometimes its best to swap, sometimes a full custom setup, sometimes... its better to sell it and buy a WRX.

[98legacygt22]

Buying a wrx is out of the question lol my credit sucks. I have parts available that can be had for a good price. Maybe 15 lbs would be too much for the open deck block. I know 8-10 could be done safely on the right tune. My goal is just to have more get up and go when I need it, I don't race except maybe messing around on the highway every so often. I have an ej22 in the car right now, but it lacks power plus I have no idea how many miles are on it. I know I could just wire in an SAFC and should be alright if I leave it 10lbs or under but would just get crappy gas mileage. I can take apart motors and put them back together, its like second nature to me. My plans are a stock 06 wrx turbo, but the 2.5 heads will just bolt onto the ej22 no mods needed?

[mike-tracy]

I moved your thread to this forum because this question comes up a lot. But on to your questions.

-You can bolt on the ej25d heads just fine, you just need to drill and tap the passenger side head for coolant and oil passages. The problem with ej22t (pistons) and ej25D heads is it drops your compression down to about 6.7CR from 8:1, partially because you have to use the thicker ej22t head gaskets since the ej22t pistons protrude past the block at tdc. So you'll need to run over 10psi to feel it, lol.

-I recommend just finding a set of SOHC ej22t heads. They are dirt cheap since no-one wants them. Then you have turbo cams and plumbing all ready to go. CR will be 8:1, so comfortable for boost. 15psi will be fine if you can control the fuel and air.

-Open deck blocks are fine as well - subaru used them all through the early 90s into the early 00's IIRC, from 220hp to 280hp. Only thing that might be a problem is the cylinder walls can become out of round on the higher mileage ej's. Also, subaru sold pistons in A, B, and C sizes to match the variances in the production of blocks. So even if you have perfect cylinder walls, your piston to wall clearance may not be ideal unless you get lucky with the pistons. So 15psi might be too much. :(

-electronics I don't know much about. This is why I mentioned a USDM WRX swap - most tuners can plug into the WRX's ecu and tune it without any standalone or piggy back. They can disable check engine lights and enable you to pass emissions.

Couple of links to ponder:

viewtopic.php?f=31&t=3347 (https://sl-i.net/FORUM/viewtopic.php?f=31&t=3347)
viewtopic.php?f=39&t=22065 (https://sl-i.net/FORUM/viewtopic.php?f=39&t=22065)

Some swap fun:
viewtopic.php?f=31&t=22527 (https://sl-i.net/FORUM/viewtopic.php?f=31&t=22527)
viewtopic.php?f=31&t=19862 (https://sl-i.net/FORUM/viewtopic.php?f=31&t=19862)
viewtopic.php?f=31&t=19968 (https://sl-i.net/FORUM/viewtopic.php?f=31&t=19968)
http://forums.nasioc.com/forums/showthr ... ?t=1102629 (http://forums.nasioc.com/forums/showthread.php?t=1102629)

[lord flashheart]

99 EJ22 + EJ25d heads = about 9:1 absolutely awesome ratio for boost.

[98legacygt22]

Ok so a little update, last weekend I picked up a set of EJ25D heads from a 98 forester ($100 and their in EXCELLENT shape), and on Thursday I picked up a td04 from a 2003 Wrx ($60 with no shaft play). I don't think I will have to drill out any part of the 25D heads for the coolant and oil passages, another guy here in CT just built the same motor (minus the turbo) and he just used gaskets from an ej22 that had the same ports as the ej25d heads with no drilling and he has logged over 600 miles so far with not a single issue. My EJ22 is from a 95/96 so my compression ratio with the 25d heads should be about 8.8:1 from what I am told and that will be great for 8-10psi.

[Garrison]

Ok so a little update, last weekend I picked up a set of EJ25D heads from a 98 forester ($100 and their in EXCELLENT shape), and on Thursday I picked up a td04 from a 2003 Wrx ($60 with no shaft play). I don't think I will have to drill out any part of the 25D heads for the coolant and oil passages, another guy here in CT just built the same motor (minus the turbo) and he just used gaskets from an ej22 that had the same ports as the ej25d heads with no drilling and he has logged over 600 miles so far with not a single issue. My EJ22 is from a 95/96 so my compression ratio with the 25d heads should be about 8.8:1 from what I am told and that will be great for 8-10psi.
You should go with a Td05-16g, it will spool almost as quickly as your Td04 but will last to the rev limited and runs happily in the 8-20psi range.

[mike-tracy]

http://bbs.legacycentral.org/viewtopic. ... &start=100 (http://bbs.legacycentral.org/viewtopic.php?f=5&t=38247&start=100)

[98legacygt22]

http://bbs.legacycentral.org/viewtopic.php?f=5&t=38247&start=100

Ah now I understand, for the oil return cant I just drill and tap the passenger side valve cover? I had looked at another build and for the coolant they just tapped in to the heater core hoses. Def going to favorite that page, a lot of useful info. Thanks! I'm excited to get to work on it, I just want to have all the parts first.

[Garrison]

Finally had a chance to read through that entire thread, from the 1st post onwards.

Impressions:

I see the validity of going for the ej22t pistons/ej25d heads combo now. The concept of just running a lot more boost is appealing, but I'm guessing the stock drive-train isn't designed to hold that sort of power. Just a thought

That being said, more boost is always better! :smt026


Food for thought, for about $400 you can get a set of forged ej22 pistons on ebay and they have something like 8.0-8.5CR

[98legacygt22]

Finally had a chance to read through that entire thread, from the 1st post onwards.

Impressions:

I see the validity of going for the ej22t pistons/ej25d heads combo now. The concept of just running a lot more boost is appealing, but I'm guessing the stock drive-train isn't designed to hold that sort of power. Just a thought

That being said, more boost is always better! :smt026


Food for thought, for about $400 you can get a set of forged ej22 pistons on ebay and they have something like 8.0-8.5CR

That would be awesome! the pistons are the only part I am worried about. I think I just want to run 12psi and that will be it. I drive like a grandpa on a sunday wherever I go so I wont be into the boost all that much anyway. The ebay pistons are trustable? I found a set of weisco pistons but I am not sure if they are forged or not. So these would work with my 95/96 EJ22? http://www.ebay.com/itm/WISECO-SUBARU-E ... 270wt_1037 (http://www.ebay.com/itm/WISECO-SUBARU-EJ22E-97-5-MM-FORGED-PISTONS-K601M975-/250878897624?hash=item3a698c2dd8&item=250878897624&pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr#ht_4270wt_1037)

[Garrison]

Yeah those would work, and yes they are forged. If you read through the description is says "(Our pistons are) made from in house forgings" I seem to recall seeing them a little cheaper though. Perhaps a go-around on the subaru B/S/T boards would net your a set for less coin?

[lord flashheart]

I run wiseco in my car. They are imho the best for the money. I've seen them pushing 700whp and holding strong. JE are good, too. (Because JE and wiseco are owned by the same people) I personally am not a fan of CP pistons. Group buys are much much cheaper as well...