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1996 Legacy Lx Sedan
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Discussion Starter · #1 ·
Hey all

A mate of mine had some spare Subaru heads off of her fathers car from many many many years ago, I’ve somehow come around to getting these off of her and am a little lost as to what they are. Is there any chance someone in here could help me?

This is my first time seeing an engine/engine head apart so forgive my ignorance on any slip ups.

I want to get one thing clear off the bat! I AM IN NEW ZEALAND, NOT THE USA!
There may be contradictions inbetween the JDM, USDM, AUDM and EUDM sti’s but I would still like to test my luck and ask all of you. These parts are most likely AUDM/JDM so if you know a thing or two, I’m calling on ya!

From my understanding these are v3 STi heads - due to the RH-B and LH-B castings on the side of the head.
58-ABC855-E886-4864-B656-AAD796-F7-EEA1
However then there’s a couple contradictions, I’ve read that v3 sti cams (Atleast USDM from what I can tell) have the codes r4in, r4ex, l4in, l4ex as well as a line going through the “R” and another to the right of the “4”. The cams my engine have are coded r3in, r4in,l3in and l3ex with only a single line to the right of the “3”.

116-B6953-AFD2-4-DED-BB5-C-7-D462-B43-E8-A7
FFF034-BC-2-BA0-4-B0-A-B327-A95-F9-D83016-F

While browsing through Scoobynet I saw a post talking about v2 Ra camshafts and that’s when I found this : 7-C0-D2-FE1-E07-B-46-DA-8133-4-AFD9-B1-CF1-F0
THATS THE SAME CODE AS MY CAMS!!! But then I saw the second line and got sad .
Prior to this, I hadn’t found anything with the same camcodes.

V3 STi heads are supposed to have valves marked with IH and EH for the Intake and Exhaust respectively, mine has I D N on the intake and I haven’t gotten around to cleaning the exhaust valves.
7-EC88977-6522-49-E9-982-D-B18-B12-CF6677

I hope some of this info and these photos can help point us in the right direction to identifying these heads! If any new photos are needed/ hosting drops just let me know and I will sort it ASAP

Any help is much appreciated! Assuming these heads are either v1/2 or v3/4 they will be getting slapped onto an Ej18 for a turbo build If you have any experience with headswaps, ecu tuning/flashing or just interested make sure to follow along too!

Cheers for any and all the help,

Dean.
 

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2000 RSTi
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Do the buckets have shims? How about a pic of the heads with the cams removed?

It's possible your heads are a mix and match of parts. My old ej20k STI heads, I replaced the shim-under-buckets with shimless buckets from an ez30R. And I replaced 4 valves that got bent with aftermarket inconel ones. My current ej20k heads are definately WRX with shim-over-bucket, but I swapped in EJ20R (Legacy twin turbo) cams, which have the same or very similar cam profile as STI. So anyone looking at either of my ej20k heads is going to have a head scratcher on their hands 😂
 

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1996 Legacy Lx Sedan
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16 Posts
Discussion Starter · #3 ·
I’ve been given the heads without buckets or cam caps so I’m not too certain on that one sorry, I thought I actually attached a photo of the heads by themselves 😂 here it is : 755-FF614-A00-A-42-BE-9-F77-6943992-A1-A3-D

Yeah I was thinking something along the lines of that too haha, it’s been doing my head in so far so I’m glad to hear I’m not the only one that got caught in this mix match mess haha.

Bolt holes seem to indicate it’s a v3/v4 head from what I can tell, I’m just trying to make sure what I actually have so I know what I’m working with and then what parts I need to buy, I know I need valve covers, cam guides, buckets and shims (not sure under or over but we’ll cross that bridge eventually)

Cheers for the help again Mike, You’ve saved me many hours of head scratching and clueless searching!
 

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I'd grab all that stuff from a junkyard car. An ej20D or ej20k or ej20r or ej25d would have all the parts required. Shim over vs shim under, don't worry about the latter. Its obsolete and the under-shims are unobtanium. And if you can find em, expect to spend big money per shim. Like I said, the 4 engines I listed above will have the compatible shim over buckets, all at wrecking yard prices.

If you want to be super baller like my STI heads I mentioned, buy like 3-4 EZ30R engines, and harvest the solid exhaust buckets from them. Then part or scrap those 3-4 engines. I promise as crazy as that sounds, you'll save money compared to ordering 16 of those buckets from Subaru. This gets you a lighter valvetrain that can rev slightly faster (lighter and theoretically faster than the STI shim-under-bucket setup), for $$$$! :mad:
 

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Not all EJ25Ds though. IIRC, the earliest ones had HLAs (US model year 96 and maybe early 97?)
 

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He's in New Zealand. I was told only the US got the HLA ej25d?
 

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ah! I didn't even consider that, so you're probably right. Subaru sure loves its minor variants ...
 

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1996 Legacy Lx Sedan
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Discussion Starter · #8 ·
Awesome cheers for the speedy replies, looks like I’m adding some ol dohc na ej20s to my shopping list :D I’ll make sure to hop on that as soon as this Level 4 Lockdown has dropped!
Assuming that these are ej20k heads they should straight bolt onto the ej18 block right? Pretty sure ej18's only came phase 1 but I could be mistaken.
I haven't begun looking into valve clearances/headgasket thickness or anything of that sort just yet but I know I need to get onto that ASAP for this tiny turbo project.

Thanks again guys, will keep you posted :D Just waiting on ol covid now!

Cheers,

Dean.
 

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The ej20k heads bolt on to phase 1 or 2 blocks. You can use (preferably) ej20k STI head gaskets, but ej20k WRX or any ej20g head gaskets will work also.
 

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Discussion Starter · #10 ·
There are heads that bolt up inbetween bolt phases? I’ll cross that bridge another day but that’s just blown my mind a bit haha.

I’m glad to hear that the EJ20k headgaskets are the ideal set, is there any particular thickness I should be looking into though, or should I be looking for a OEM one?

I was thinking I could go for a MLS Cometic Headgasket and get it as thick as possible for a lower compression, but if that’s been done and dusted a million times with trivial results then I’ll drop the idea and rest with whatever you suggest.

Thanks again Mike, honestly not sure if I would’ve even gotten this far without ya ( or Atleast this quickly haha)

Cheers, Dean.
 

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Cometic's demand perfection from your block and heads mating surfaces (ie. they actually blow in the long run without near-perfectly machined surfaces), and they are overkill. The STI ej20k HG's are also MLS, and the WRX/forester/etc ej20k/ej20g HG's are made from graphite. Realistically you aren't going to exceed what even the graphite gaskets can handle, and you know the factory gaskets are going to be the correct thickness.

A set of 2021 STI heads will bolt onto your ej18 block! A set of 2021 WRX heads won't, because those went to the FA engine series.
 
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