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backwards frankenmotor?... ej22 block with ej25d heads... anyone done it and driven?


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i know Ivan mentioned it in a post at some point,  but is this setup worth the effort?   i think they said it was like 8:1 CR.  so it would be better suited for a turbo application

 

wondering if anyones built one and driven with it in a car and what they thought of it. (or how bad did it suck?)

 

to get any power out of it, thoughts about something like a small turbo (saab? ea82t?)  but running on stock ecu and just maybe some larger injectors. 

 

for reference,  95 ej22 block and 99 ej25d heads is what i have

 

 

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a guy ran turbo pistons with no turbo for a low compression ratio and it was fine as a daily driver.

 

i looked into it and discussed a couple years ago, should be a thread somewhere on this forum.  make sure the valves aren't  too big for the headgasket, i over layed them but can't recall the results.

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most of the info on this swap is for turbo application,

 

here is a good compression ratio chart, parts of it are inaccurate as it doesn't break down years of engines and their different stock ratios.

http://www.b4et.com/docs/cr_matrix.pdf

 

Realistic expected ratio with that combo is 9.0-9.3:1 which wouldn't be too bad for a non turbo application.  You won't need to worry about the valves unless you go with a really thin head gasket or shave the heads too far.  BTW, if i could find a good set of 97-99 ej25 heads I'd do something like this as well.

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cool thanks for the links and info guys,   im contemplating just putting this engine together on the shelf for the sake of it'll be a quick swap if my frankenmotor dies.    all i should need is a timing belt because i made a belt out of the EJ25 belt, LOL

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  • 3 weeks later...

I have a friend who used a 2.2 bottom end with 2.5 SOHC heads on it. He says it's high 8's for compression. I can't remember what turbo he runs on it, but it makes 230whp, and has for the last year with no issues. And he doesn't treat the thing nice. It's built out of scrap parts from his shop and runs amazingly well.

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I have a friend who used a 2.2 bottom end with 2.5 SOHC heads on it. He says it's high 8's for compression. I can't remember what turbo he runs on it, but it makes 230whp, and has for the last year with no issues. And he doesn't treat the thing nice. It's built out of scrap parts from his shop and runs amazingly well.

He had a VF39 last I knew.

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I like to use the 90-94 ej 2.2 with twin cam heads is higher comp ratio but this works good have biult 4 or 5 now way more bottom end reliabilty and stock management no check engine light and close to same power about 10 % less but no piston slap and probly better milage the first one i did has 150000kms on it since runs flawlessly. I have even done the 2.2 51 2.2 with 01 and up single cam heads thiss works good to

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  • 2 months later...

I am driving this combo in my car right now.
I have made 2 EJ22 DOHC hybrids, 1 w/222 block & 1 w/22E block (current), both used 25D heads. 
In order to mate the 25D heads & EJ22 block sucessfully, you absolutely MUST use this kind of head gasket ->http://www.ebay.com/itm/Genuine-Subaru-OEM-Head-Gasket-Pair-EJ22-99-01-Impreza-99-Legacy-NEW-NR-/230801303335?pt=Motors_Car_Truck_Parts_Accessories&hash=item35bcd46727&vxp=mtr.

The necessity is caused by the 22E/T HGs not having the same cooling ports as the 25D heads. 
Water pressure gets higher than one would think & the mismatched cooling ports will very likely cause blown gaskets. 

I've been running my combo in N/A format for about 20k miles now w/compression ratio of 9.5:1 & the low end is a little lacking compared to the 22E at full initial acceleration but the midrange to redline has much more kick to it than a regular 22E. 
The power produced is between a 22E & a 25D with a 25D-like power band (about 145-150ish bhp) & power falls off around 6400rpm. 

The block has a little piston slap (I used a 95 22E) but it is still a very tough engine that likes being in the higher rpms (2.5k up).
My engine sees anywhere from 1.5k to 3k rpm daily & hasn't given me any issues as of yet. From it's current condition, I can get 100k miles out of this combo w/no major issues. It does have light mods (intake manifold spacer, MSD ignition coil, custom cut intake, headers) but it is proving to be quite the workhorse. I'd recommend this build for anyone looking to replace their blown 25D block & want to either boost or run it in N/A if you wanted to keep the 25D heads. 

Edited by DOHCEJ22E
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dude there is 50 of them have done lots ej22b with 99 outback twin cam heads 90 2.2 with 03 251heads 2.2 na with outback twinn cams 2.5d with 2.2 heads 1.8 with 2.2 heads my favort one the 2.2 na with 2.51 phase 2 heads this engine is a workhorse and uber reliabble. Note all theese engines require speatial time and care and mods to make work headgasket mods timing belt mods addjusters mods ect. Head port matching and intake mods. The engine combos have differnt block deck heights I also plane block halfs and heads then all deck to piston heights are checked and addjusted accodingly

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