I need to replace an EJ25 shortblock....

[LegaWaga]

...in my 2000 Legacy L 5speed. The block itself is cracked and there is rod knock, so a rebuild is out of the question. What cars have a block I can use? How does SOHC or DOHC affect me here, and newb question, which do I have? Also, what would happen if I used a 2.2(t)L block with my 2.5L heads and such?

[anothernord]

22T block + 2.5 heads = Invincible turbo engine. That course would require a turbo, and matching engine management, of course. Your block is a Phase II EJ251 if I am correct.

[LegaWaga]

22T block + 2.5 heads = Invincible turbo engine. That course would require a turbo, and matching engine management, of course. Your block is a Phase II EJ251 if I am correct.

Ive been doing some reading on that hybrid build, but the hard part is finding a block/motor. :/

[anothernord]

The only problem with the 2.5 heads + 22T block is the ultra-low CR that results. While that low of CR means it can take untold amounts of boost, low end performance and gas mileage would suck without doing things like really thin headgaskets.

[LegaWaga]

The only problem with the 2.5 heads + 22T block is the ultra-low CR that results. While that low of CR means it can take untold amounts of boost, low end performance and gas mileage would suck without doing things like really thin headgaskets.

are there metal hg's that can compensate for that, or am I wrong in thinking that hg issues could surface because of that? I am totally still a newb here, but are there links to dyno charts or anything from this swap?

[loganmossmusic]

On an unrelated note, did you post on the Portland Craigslist looking for one? I just saw a listing with someone asking for a shortblock and I was just wondering if it was you.
On topic: I think you should just replace with a block made for your heads, so you dont have to add a turbo

[LegaWaga]

Well I am not opposed to building a turbo, as long as it isnt an extremely difficult build. I have two swapped toyotas, but no turbos yet. My heads are good to go, and only have 106K miles, the block took in water and that was the end of that...

BUT, if I can find a cheap enough EJ25 block I will just do a straight replacement of the block. I am just curious, if I just did that, does it matter what year I get the 2.5L from?

[Huffer]

Get a shortblock from a 2000 impreza rs. Sohc, 2.5l. Put your heads on and roll out.

[LegaWaga]

Will there be any change in power or does it even matter if the motor was DOHC or SOHC?

[Huffer]

Your heads are SOHC, the block still has 4 pistons. Won't matter, and the compression should be around the same.
Likewise, you can get a SOHC block from a 2000-04 Legacy and attach your heads. Same equation.

[LegaWaga]

well I lucked out because my friend replaced the motor in is Forrester due to hg issues, so I now have a good block to swap into mine with 110K miles. Other than the idea of a rebuild which I cant afford anyway, what else should I do prior to installation with new gaskets and such? I plan to have new hg, valve cover, and t-belt. Anything else I should do?

[Huffer]

Some people will say piston rings, I'll just suggest the usual seals (check your rear oil separator plate), pumps. If you can spring for it, some street grind cams from Delta Cam + new valve springs would be slick for your car. It's only two cams for your engine, whereas for the older DOHC engines it's 4, so you get a much better deal.

What year motor is the Forester engine?

[LegaWaga]

It from like a 99 or 00 iirc. It is supposed to be the phase II.

[LegaWaga]

So I just noticed two things that I overlooked before. The block I am planning on using is a DOHC EJ25, that was bolted to an automatic tranny. Will that matter for me much? It looks like I can just use the flywheel and clutch pack on the donor block, and as long as I am switching over my SOHC heads and intake mani, I should be fine. Does that sound correct?