Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Phase 2 ej22 / phase I ej 25 mix and match

Featured Replies

I'm looking at a '99 Legacy 2.2 MT with an engine knock. (I haven't examined the car yet, but let's assume the block is hosed)

 

I have a '97 EJ 25 DOHC phase I engine (not perfect, but good enough for my low mileage beater needs) sitting in my garage.

 

Is there any way I can mix and match parts here to make one good-ish engine out of what I have? Phase II ej 22 heads & manifold on a phase I ej 25 block?

 

I live in an emissions inspection state, so I can't have any CELs.

 

Nathan

the blocks are interchangeable. i just did Phase II EJ25 heads on a Phase I EJ25D block. on mine i needed to use the thicker 610 (last 3 digits of the Subaru part number) headgasket to verify clearance as that combination brings things closer together and my heads were slightly below thickness spec. that will be you only issue, if any at all.

Any thought that the engine knock may be piston slap? The noise, I am told sounds similar. If so, with piston slap, the condition is not deadly to the engine, and you can drive that engine for many more miles.

it can also be a failing timing belt tensioner, they can "knock" loudly too sometimes and be confused for something more ominous. pull the cover and you'll see it "moving"/"slapping" up and down. they can be bad enough to make noise but not cause the belt to slip.

  • Author

Gary-

 

You mention swapping phase I and phase II ej 25 blocks- I'm asking about using '99 phase II ej 2.2 heads on a phase I ej 25 block. Do you know if that'll work? I'm just worried about coolant passages lining up properly, bore sizes, etc.

 

I'd definitely inspect the tensioner and consider piston slap if I had the car to inspect- but I don't, so I'm just running though the worst case scenario (rod knock, needs a block) to see if I'm even interested in looking at the car.

 

Nathan

Gary-

 

You mention swapping phase I and phase II ej 25 blocks- I'm asking about using '99 phase II ej 2.2 heads on a phase I ej 25 block. Do you know if that'll work? I'm just worried about coolant passages lining up properly, bore sizes, etc.

 

I'd definitely inspect the tensioner and consider piston slap if I had the car to inspect- but I don't, so I'm just running though the worst case scenario (rod knock, needs a block) to see if I'm even interested in looking at the car.

 

Nathan

it'll bolt together, it's called a Frankenstein motor. It's pretty well documented on this site and others. It raises compression to give you pretty good low end grunt. A lot of people install re-ground delta cams at the same time to get even more power.

  • Author

I'm pretty sure the popular "frankenmotor" is phase I ej22 heads on a phase I EJ25 bock. I'm talking about phase II ej 22 heads on a phase I ej25 block.

I'm pretty sure the popular "frankenmotor" is phase I ej22 heads on a phase I EJ25 bock. I'm talking about phase II ej 22 heads on a phase I ej25 block.

 

in part it depends on the car it is going into. the 99 ej22 phase 2 heads and intake will not match a 95 - 98 car. they will match a 99 (00 - 04?) car . the 99 ej22 was an odd duck. it was the 99 car, but the 00 engine.

 

the 99+ ej22 phase 2 heads will swap intakes with the 00+ ej25 heads. that is not true of the rest of the ej22s in the 90s.

The best matchup for the "Frankenstein" is Phase II to Phase II. Go to NASIOC , there is a 75 year 43.96 million post thread.

This is post #329:

engine block + heads=

"Best"

p2 2.5 + p2 2.2: highest compression ratio (stock gasket) better manifold options, decient heads

Good

p1 2.5 + p2 2.2 again good manifold options and decient heads

p2 2.5 + p1 2.2 dual ports (header options & possible better flow than single ports)

p1 2.5 + p1 2.2 dual ports

Ok

p2 2.5 + p1 2.2 single ports

p1 2.5 + p1 2.2 single ports

 

thats for running completely stock, aka slaping it together and going.

 

FWIW I too have a 99 Legacy 2.2 with a rod knock. I don't know what to do either. Finding a decent 99 ph II 2.2 is HARD. Do I want to spend $1300 to have it rebuilt so I have a 99 Legacy wagon worth $1500 and an engine worth nearly as much as a car? Do I sell it as is? Who wants a car with a rod knock and using oil? Silly Subaru, one year for an engine. Cripes!

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.