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EJ22 heads on EJ20


glcoupeguy
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got an EJ20 shortblock from a junk yard awhile back. couldnt afford the heads.

i recently aquired some EJ22 heads though. looking for input before i spend money at the machine shop. im also planning on turbocharging it and wondering how the compression will be with stock internals. yay? nay?

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yes, definitely do-able. I've got a friend running the opposite in his impreza now, 22 block with 20 heads.

 

 

but probably not ideal.

 

compression depends on exactly what it is, and what headgasket you use. assuming it's a USDM EJ20, it has to be an EJ205 ('02-'05 WRX), which means the pistons are designed for ~7.7:1 compression. and typically speaking, heads for a larger bore have a large quench volume, which will drop your compression ratio a bunch.

 

I don't remember off the top of my head which engine uses which thickness headgasket, but that's your only chance to recoup some compression. But I think you'll probably end up with a CR of about 7.5:1, if you're lucky, you might be able to bump it up to the stock 7.7ish. in any case, it will definitely need to be forced-induction to have any torque, at all.

 

although the 2.2 heads are SOHC, which are a substantial bottleneck.

 

 

 

really, you're going to struggle just to get stock WRX peak power....with a crappier torque curve.

 

you'll also have less displacement, and still an open deck block. Also, a junkyard WRX block......eek. IMHO you'd be better throwing a few psi and some supporting mods at an N/A compression EJ22.

 

 

this is all just off the top of my head, though. and filling in the blanks as to exactly what you have (MOST EJ22s have 9.5:1, but the newer ones went up to 9.7....so if you're using those heads, you might have a better shot. also, if it's an EJ20 shortblock from another market....things will change. But probably 90% or more of the EJ20s on the planet were turbo. so you'll be looking at pretty low compression).

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this is all just off the top of my head, though. and filling in the blanks as to exactly what you have (MOST EJ22s have 9.5:1, but the newer ones went up to 9.7....so if you're using those heads, you might have a better shot. also, if it's an EJ20 shortblock from another market....things will change. But probably 90% or more of the EJ20s on the planet were turbo. so you'll be looking at pretty low compression).

 

IDK Chux, it could be a JDM take out motor.

 

I've seen several in Legacies and imprezas junkyards.

 

And there were TONS of non-turbo EJ20s. IIRC, Europe got them in legacies instead of 2.2s because of there emissions laws (staggered by displacement)

 

I would say look at the pistons. If they are deeply dished they is likely a WRX motor. If they are not, or just slightly dished, it is likely a JDM or EDM motor imported.

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IDK Chux, it could be a JDM take out motor.

 

I've seen several in Legacies and imprezas junkyards.

 

And there were TONS of non-turbo EJ20s. IIRC, Europe got them in legacies instead of 2.2s because of there emissions laws (staggered by displacement)

 

yea, definitely could be from another market. I've never seen one in a junkyard though...so I don't know how common that might be.

 

 

yea, I suppose there are a lot more N/A 2.0s than I was thinking. but turbo ones are still far more common, in general.

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yea, definitely could be from another market. I've never seen one in a junkyard though...so I don't know how common that might be.

 

 

yea, I suppose there are a lot more N/A 2.0s than I was thinking. but turbo ones are still far more common, in general.

 

Funny thing.

 

So yesterday a buddy of mine comes by with a Legacy he just bought from the Junkyard (hadn't been fully *processesed* yet). It had a good tranny and a bad motor (motor in pieces in trunk). So I hooked him up with a used EJ22, dropped it in and got ready to send him on his way. Well we began to unload his old motor for me to keep as a core.

 

well guess what? It is an EJ20. Very shallow dish to the pistons. Headgaskets stamped EJ20 too, so I belive this is a JDM motor that got shipped over and dropped into this car at some point in the past.

 

So now I have an NA EJ20 sitting on the floor of my shop. Perhaps my next EJ swap into a wheeler will be a 20.

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thats a funny story.. Two years ago at the place I used to work at we got a legacy that had the same thing.. Engine was in the truck tore apart. I started digging around back there and it was a non-turbo EJ20 also. So they did make their way all the way across the USA, even up here in Alaska as pullout engines.

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I was comparing heads of the EJ20 to an EJ22 to see if they would in theory work on a 2.2

 

The EJ20 heads are roller rocker, WITH dual port exhaust. Sweet. All the USDM 2.2 that had roller rockers where single port.

 

Also, comparing the blocks. The EJ20 has WAY thicker barrels around the cylinders. Also, there are no nothces cut out of the barrel edges for bolt access, like there are on 2.2 and 2.5 engines.

 

Too bad that # 1 cylinder looks like the surface of the moon. damn. Anyone got a line on .020 over NA EJ20 pistons?

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  • 1 month later...

i never could find any information on this combination except from my own thread. the EJ20 is n/a for sure. any idea on the compression? im hoping for something around 8.5.

 

the engine is going into a 1987 three door body and its pretty stripped down. it weighs about 2100 - 2200lbs so i wont need a massive amount of power but it will be turboed. (looking for 200 - 250hp but i wouldnt mind more :))

Edited by glcoupeguy
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  • 7 years later...

Hi,

 

Looking for the following scenario.

 

I am doing EJ20 conversion for a VW bug.  (This is not a VW conversion-related question)

 

Can the North American EJ22 SOHC  (naturally-aspirated 1991 Subaru Legacy or the EJ22 the forum suggests) head 

 

be bolted to the JDM EJ20 SOHC engine?

 

I know the head might not be the best one.  The problem in the VW installation to access the EJ20 spark plugs, would either result in cutting the car or removing the engine.

 

The EJ22 is from the top or the head.  

 

Reasoning:   I can get EJ20 JDM engines all the time.  EJ22 seems to be hard to find on a reliable basis.  

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Heads and intake need to match generations. Phase 1 block (pre-1998-ish) will take phase 2 heads and vice versa but the intake has to suit the heads. Wiring should also be a bit easier with a phase 1.

A complete phase 1 EJ22 should be pretty cheap, take off the intake & heads and swap on to your EJ22...

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