GD 2.5 into 93 Leg wagon (L)

[matt72]

I am looking to see what I'm getting into here with a small swap. By small I mean not looking for any huge gains, only to "perk" things up a little considering I have a sohc GD 2.5 (2002 I think) long block at my disposal. It will need rebuilt but I'd like to use the heads along with the block since the Legacy valves are so small. I figured I would just swap over all the accessories from the ej22, but I thought I read though that there will be issues with the throttle body among other things. Am I stuck with putting the ej22 heads on the 2.5 block (high compression, right?), or can I use the 2.5 heads as well? I would imagine the intake manifolds line up completely different......

[Legacy777]

I don't know if anyone has really ventured that far forward with using a "new" engine in these older cars. One of the biggest issues you'll run into is the engine management. You could probably run that 2.5 with the 2.2 ECU, but it is not going to be ideal. Plus I'm unsure whether the newer 2.5's have an EGR valve or drive by wire throttle, etc.

My recommendation would be to try and find something a little older to help improve the compatibility with your Legacy. This thread has some info on swapping a 2.5 into a Legacy. The pictures however don't work

http://bbs.legacycentral.org/viewtopic.php?f=5&t=15368

[matt72]

Thanks Josh. Just to clarify, I'm not intending to use the whole long block per se, just what I can in regards to the block and heads. I plan on using the crank/cam gear/ sensors etc from the Legacy. I'm wondering if the stock ej22 injectors would be able to fuel the 2.5... whether it's just the block or the block and heads together that I end up using. I'll have to eyeball the parts I have in my junk inventory and see what I can make work....

[Legacy777]

Maybe you can provide some additional details on the setup you're thinking at using.

I guess the issue I've read about, but not personally experienced or seen first hand is that matching up 2.5 heads to the 2.2 block may not work. I can't comment on what combination of heads vs. block work, but that is something to keep in mind. Also, you pretty much have to use the intake manifold for the heads that you use. So if you use the newer 2.5 heads, you'd need to use the matching intake manifold, which means you would be using the injectors for that manifold and all the associated sensors, etc.....which leads you back to the engine management.

I may be reading too much into what you're wanting to do, so if you can provide specifics on what you're thinking, that would be helpful.

[matt72]

I guess the main thing I really want to do is use the 2.5 short block, simple enough. I was hoping though, if possible, to use different heads given the small size of the valves in the older 2.2 heads. I'll use the stockers if I have to (given they will even mate to the 2.5 block), but was wondering what it would take to use the 2.5 sohc heads/block with the 2.2 ecu and peripherals like cam gears etc. Like you said though, i have to use whatever intake manifold that matches the heads. I guess then you run into the problem of different throttles bodies that will not mix and match with different manifolds..as well as injectors. So I may be stuck trying to just use the 2.5 shortblock/2.2 heads, but I guess that combo yields a high compression ratio. I also have 2.2 sohc heads from a 2000 obs that might work, but then I'm stuck with single exhaust ports. They do have a lot larger intake/exhaust valves...in fact look to be the same size the the wrx ones oddly.


I guess the "Frankenstein" motor is what I'm trying to get close to...as posted here http://www.ultimatesubaru.org/forum/sho ... =ej25+ej22

[Legacy777]

Yeah, unfortunately, there's not a clear cut upgrade path. You definitely listed some of the challenges. I don't recall if Jason ran into any issues using the 2.5 engine crank/cam triggers with the 2.2 ECU. There definitely is different crank/cam trigger setups and that needs to match the ECU.

I wish I had some additional suggestions for you, but I don't really have anything at this point.

[matt72]

Well thanks for your input, at least I've got my mind rolling in the right direction lol....

[MikeyMeyagi]

if the intake manifold will bolt on, which i think it will, id use the whole motor. use the red sidefeed injectors from the legacy, they are the same size as the topfeeds in the 2.5. the legacy ecu will run it fine with the crank gear and cam sprocket from the 2.2 liter.

[matt72]

Hmm...i have a spare set of sti side feeds, maybe i can wheel and deal with somebody.