EJ25D block swap to EJ257 block

[Dirthead]

I have a 99 legacy limited outback with an EJ25D (I believe it is phase I). As the story goes blown HG's. My question is I have found a 2006 Subaru WRX EJ25 and I believe this to be a "US Market Impreza WRX STi MY04~MY07 (300 hp, 293 hp (New SAE standard))" - EJ257. I have all the parts from my EJ25D I have read here (http://www.ultimatesubaru.org/forum/showthread.php?t=112584) that it is possible to swap my heads on to the EJ257 short block and the intake and basically be back up and running. Will this work? Am I short siting other things that I will need to do to get it to work such as wiring? My goal is just to get the car back up and running pass emissions and inspection to make this a daily driver. I do not need additional power and I am not trying to Frankenstein. Any help with these questions would be greatly appreciated.

 

Thank you,

Dirt

Edited March 19, 2011 by Dirthead

[WJM]

It will work. You'll be a little down on power but it'll get you down the road.

 

Use the 11044AA610 gaskets. Do NOT use the 642/670/770 gaskets as the pistons will hit the cylinder head at TDC.

 

Treat everything as if you were putting a stock EJ25D block back in and you'll be fine....aka it'll just be a basic short block assembly swap.

[Numbchux]

a 2006 WRX would have an EJ255, only the STi had the 257.

 

The only difference in the shortblock is the pistons though.

 

 

Either way, these are turbo motors. Which means the compression ratio will be lowered substantially. So you'll loose a bunch of power and torque. Mechanically it would work, and it'll be drivable, but not ideal. Honestly, unless you plan to turbo it, I would look for something else.

 

 

If the motor you're looking at (be it a 255 or 257) is a great deal, you could probably flip it for a decent profit, as they have more than a little value. And grab a non-turbo 2.5 shortblock (25D, 251, 253, would all work fine).

[WJM]

2006 and up EJ255's have 8.4:1 compression.

The stock EJ25D in 1996 had 9.5:1 and 1997~1999 was 9.7:1.

 

Like Numbchux said, you can flip it to some WRX/STi guy for current market value.

 

If its new you can flip it for anywhere in the $800 to $2000 depending on local market and how you advertise it.

 

If its used and known good, $300~$1200.

 

If its used and unknown, $0~$500.

 

 

Again, it all depends on your local market, how you market/advertise it and the condition its really in.

[idosubaru]

are buying this block for power or it's cheap? something doesn't sound right, i would never use this motor for what you're doing. it's normally a terrible idea.

 

if you put a turbo block in a non turbo motor you'll have low compression and low power. it'll be a huge down grade and make less power than the original 165 the car had.

 

the turbo makes the power, not the block. the block just allows more boost...but you're not boosting it so it allows for something you can't do.

 

these motors are usually really expensive. so you're buying an expensive block for qualities you're not using. let's buy a 300 hp motor so i can only get 130 out of it...see why that sounds suspect?

 

if the motor is cheap i'd be suspect of it, why would someone sell it cheap?

 

if it's cheap and good - just flip it like they said and buy the block you need.

 

you'll make money on it and get more horsepower.

 

but yes it can be done, i'm basically doing the same thing - use the part number WJM said. they didn't hand me that gasket last week when i went in to do this and the guy didn't know what i was talking about. they eventually figured it out and had them on hand.

[Dirthead]

Wow thank you all so much for the great amount of input on this. You have all really gone above and beyond in providing the answers needed to make a sensible decision. The story is this. I have been watching the local market for the last year and a half to find a replacement motor for the vehicle. In the last four weeks I have watched the motor in question (EJ255) go from 2000$ to 1300$. Apparently either no one has a need for it or there is something wrong with it. As I watched the price drop I started searching boards to determine if this would be both a mechanically feasible and logical swap. I am glad that I decided to post rather than just throwing money away. Considering that this 1300$ deal was only for this weekend and I know now that I am not missing out on anything.

 

Moving on.....

 

The next option that I have available is an EJ22 sohc I believe this was from a 94 or 95 impreza. I have read that this as well has been done provided the following configuration:

 

Use the throttle body from my 25

Use the intake that is on the 22

New fuel rails and injectors

Block needs to be drilled and tapped for the second starter bolt

Exhaust will match because they are both dual ported

 

Few items that I am unclear on is:

Can I use my 25 ecu to run the 22 motor?

 

As I understand the crank angle sensor on the 22 will not work with the expected knock sensor for the 25 therefore I would have to figure out a custom wiring solution to solve cel errors.

[Numbchux]

Yea, depending on the condition and seller, even 1300 isn't really an awesome deal.

 

 

The 2.2 is definitely an option. There are a ton of different combinations that are possible for that combo. You could use your 2.5 heads/intake, which would simplify the wiring (a slight drop in compression, so a bit less power than the stock 2.2, but not much). Or use most of the 2.2 like you mentioned.

 

You can either drill and tap the engine block, tap threads in the transmission bellhousing so it's like the 4-bolt transmissions (with a stud in the transmission for that lower starter mount), or even just run one bolt on the starter.

 

 

As I understand the crank angle sensor on the 22 will not work with the expected knock sensor for the 25 therefore I would have to figure out a custom wiring solution to solve cel errors.

 

I don't think this is an issue. I know that a Legacy EJ25D ECU (like yours) will plug in, and run, a '96 EJ22 in an impreza with no mods. And I don't think the sensors are different between the '95 impreza 2.2 and the '96 (the pinout at the ECU was different for the '95, but as far as I know, that's the end of the difference).

[987687]

I'll trade you an ej25D block for the turbo block....

[WJM]

I would not pay $1300 for an EJ25# turbo block to put in place of an EJ25D block.

 

You can buy a COMPLETE EJ25D engine assembly for that price.

 

Go check out ebay.

[Dirthead]

Numbchux -

 

ey man i did a little more research on this and local market has a

 

(Subaru Legacy 2000-2004 2.5L SOHC)

 

(Point of reference)

Wiki: http://en.wikipedia.org/wiki/Subaru_EJ_engine

 

Power ISO: 123 kW (165 hp) @ 5600 RPM

226 N·m (167 ft·lbf) @ 4000 rpm

Usage:

Impreza 2.5RS, 2.5TS 99-04 (US)

Impreza Outback Sport 02-04 (US)

Forester 99-04 (US)

Legacy 00-04 (US)

Outback 00-04 (US)

Baja 03-05 (US)

 

 

Is this the 251 that you speak from this post: "

"And grab a non-turbo 2.5 shortblock (25D, 251, 253, would all work fine)."

"

 

Do you know how I could verify that the motor is the 251?

 

If this is do you know the logistics of swapping the block in and using all my 25D components such as heads, intake, egr? I am thinking that it should all swap over.

 

Do you know what HG's I should install?

 

Would there be a drop in compression?

[Dirthead]

WJM -

 

As you indicated following quote, would I still use the "11044AA610 gaskets" indicated for a EJ25D block swap to EJ251 block?

 

Use the 11044AA610 gaskets. Do NOT use the 642/670/770 gaskets as the pistons will hit the cylinder head at TDC.

 

Treat everything as if you were putting a stock EJ25D block back in and you'll be fine....aka it'll just be a basic short block assembly swap.

 

Thank you

 

BTW - if you would like I can set you up with the contact info of the guy looking to sell the EJ255 just PM me.

[WJM]

Do you know how I could verify that the motor is the 251?

 

If this is do you know the logistics of swapping the block in and using all my 25D components such as heads, intake, egr? I am thinking that it should all swap over.

 

Do you know what HG's I should install?

 

Would there be a drop in compression?

 

With out having the VIN/Engine code tag, most EJ251 and EJ253 look the same. The PZEV engines are obvious what they are and most are designated EJ252 or EJ254. But those would work in place as well.

 

Use the 11044AA610 gaskets.

 

Compression will probably stay around the same. EJ25# (non-D) range from 9.7:1 to 10.0:1 and your EJ25D is 9.7:1.

 

Everything from your EJ25D should be used on the EJ25# short block assembly.

 

WJM -

 

As you indicated following quote, would I still use the "11044AA610 gaskets" indicated for a EJ25D block swap to EJ251 block?

 

Thank you

 

BTW - if you would like I can set you up with the contact info of the guy looking to sell the EJ255 just PM me.

 

Correct.

 

Thanks for the offer, but I am going to decline as I have no way to sell something like that for that much money.

 

Some months ago I had a few complete and known good EJ255/EJ257 short blocks that I couldnt get rid of for $600. I had to drop to $400 before I got rid of them.

 

The market around where I am is really poor and NASIOC is not proving any better.

[Dirthead]

Thank all for the excellent input again. Now I know a little more about what I have and the options.

 

What I have decided to do was get a JDM Motor. From what I have read I will need to swap intakes, fuel rails, and drill the EGR. My question is will I need to do the hg's on it or am I good with the JDM OEM hg's?

 

I just ordered the motor today and should be here next week. So close I can taste it.

[WJM]

You should probably replace the headgaskets since you are not going to be far from them. Along with the timing belt.

[idosubaru]

i would definitely replace the headgaskets, they're actually not that hard once the engine is out.

[987687]

Why don't you just swap the heads off the old engine. That way you don't have to wongleflute around with trying to drill an EGR hole in the head.

[Dirthead]

While this is an option. I have pulled the 25 apart that came out of the car to find that the it has spun a bearing on one of the inner rods. I was told that there is some concern that the heads may now be contaminated with metal shavings from the spun bearing. While this is an excellent suggestion if I were to address the concerns with the potential contaminated heads this may prove feasible, however my next concern would be comparing the heads with 60,000 miles on them from the JDM motor vs. the heads from the inoperable motor with 180,000 +.

 

What are your thoughts on this situation?

[WJM]

if the cams spin very freely/like butter in the heads, re-use.

 

If there is scoring, moderate to heavy, and they still spin freely, its a toss up.

 

In most cases in they are toast, they will not spin freely and there will be heavy scoring. DO NOT RE-USE.

[987687]

The cams have to come out anyway to get the head off. So just do a very thorough inspection of all the lobes and bearing surfaces.

[Dirthead]

Ok did the spin check on the cams and they feel a little sticky especially when they are pushing the valves. I interpreted butter as the free spinning of something similar as the timing belt tensioner. Haven't got to the bearings yet. As for the lobes they are nice a shiny. Scoring to me would look like a really heavy wear or maybe scratches. The lobes look polished and from the contras of where the lobe makes contact with the bucket compared to the unworn portion of the lobe, it just looks polished. It feels like to me the left head cams spin more freely than the right head cams. (right head handling the damaged piston bearing)

 

Gaskets originally mentioned in the follow (Thank you WJM BTW) would you still recommend these as a replacement on the JDM motor? Could you recommend a brand? Local market has felpro OEM's which I thought I had read that when replacing the hg's it is recommended to switch to either a new gasket supplied by Subaru, Bech Arnley, or Fel-Pro.. Thoughts?

 

Use the 11044AA610 gaskets. Do NOT use the 642/670/770 gaskets as the pistons will hit the cylinder head at TDC.

[WJM]

The cam is going to get sticky/stop moving when the lobe starts to make the lifter climb up the lobe.

 

As long as it moves freely when the lobes are not trying to lift a valve, its all good.

 

Use only SUBARU 11044AA610 gaskets. Do not use any aftermarket gaskets. Every one that I've seen and seen used leak/blow internally just like the older SUBARU gaskets pre-11044AA610.

 

For the EJ/EG/EA engines with the "composite" type headgasket, EXCLUDING the 1996MY EJ25D, it is 'ok' to use something aftermarket since subaru does not offer a MLM gasket as a replacement. I have seen those used with great success.

[Gloyale]

 

For the EJ/EG/EA engines with the "composite" type headgasket, EXCLUDING the 1996MY EJ25D, it is 'ok' to use something aftermarket since subaru does not offer a MLM gasket as a replacement. I have seen those used with great success.

 

Yeah, it really comes down to bore size. The larger bore of the EJ25 leaves a very narrow seal around the top of the open cylinder deck.

[Dirthead]

Again thank you all for being so responsive. A little update. So I picked up a jdm engine fresh from Japan. One of the last ones shipped prior to the tsunami.

 

I started tearing into it today and pulled the head picked up the suggested factory "11044AA610 gaskets" wow these look sweet and much more durable then the OEM ones I just pulled out.

 

However, I think I have a problem. While I was pulling the left head four buckets fell, three from the exhaust and one from the intake. I have read a few boards indicating that this is bad because I may end up with valve issues now if I put it back together and just guess at the order.

 

Likewise to this I read that I can just check the valve clearances, chart, and put it back together based on proper specification / order.

 

Do I understand this correctly?

 

As I was tearing down the heads I did get a chance to spin the cams (On the JDM) and I now know what butter is like.

[WJM]

Get a METRIC feeler gauge. Dont get the one with SAE measurements on it.

 

They are only $5 or so from any Snap On/Matco/Mac/Sears/whatever.

 

0.20mm intake clearance

0.25mm exhaust clearance

 

Despite what the manuals will say, ZERO tolerance on the valve clearance. Make sure you get them to those values. The engine will run SOOOOOOOOO much better.

 

Even if they are "close" and "in spec" according to the tolerance that the manuals have, it is EXTREMELY noticeable when you have them dead on vs "in spec" but not dead on the spec.

[Dirthead]

Very nice, excellent post thank you so much for posting that. Thats a huge boost of confidence, I knew there was a way.

 

I do have a few questions just a thought as I have been tearing down the engine:

 

Could I use the jdm fuel injectors on my usdm intake and fuel rails?

 

Any thoughts on drilling the hole for the egr? It looks like it is pretty much already there I just need to finish drilling and then tapping. How about the drill Millings? What is the best way of cleaning these so I don't contaminate the lower exhaust valves and egr pipe?