Help with EJ251 swap

[Nikki_90]

I've read conflicting information about this, everything from just swapping engine harnesses over to frankenmotor builds, and I'd like to get some solid thoughts on it. I have a FWD Auto '93 (EJ22) with no engine, but ac pump, power steering, ecu, trans, and all wiring intact (the guy just unplugged everything, pulled the engine and parked it). I also have an EJ22 (which is dead, but can be used for parts if need be) from a '96 available, as well as the running EJ251 in a 2000 Outback (also automatic). I want to install the 251 from the OB into the '93 as simply as possible and would like to know your advice on how to do it. I'm aware it isn't the BEST reliability or for performance, but I want to use what I already have to make it work. I hope this is the right section, I'm kinda new around here and am finding myself increasingly frustrated at the conflicting information I'm reading.

[cj91legss]

You would need the heads and intake manifold from the 93 if you wanted to use the 251 short block. You would also need the crank timing gear from any phase 1 engine. That 251 is phase 2 so it has different crank timing triggers than phase 1.

It can be done, but I don't know how the ecu handle the timing on a 2.5 liter block. I think you would HAVE to run premium fuel with this setup. Sl-i.net may have some more info on this particular setup.

I have heard that some ej22 heads flow better than the ej25 heads (SOHC) but I also haven't built an N/A engine like what you're asking.

[Nikki_90]

I was hoping to use the entire 251 and drop it in. I do have the intake manifold from the 93, the only heads I have are from an EJ22 from '96 though. Are they the same heads as the '93 do you know?

[cj91legss]

You won't be able to use the entire 251. The electronics are all sorts of different. The 96 heads may be the same as the 93. Some of the second Gen stuff and Impreza stuff is different tho. I.e.... single port exhaust versus dual port.

The 96 heads may have egr as well.

[Nikki_90]

I'll have to take a look at the 22 in the shop, I'm hoping to do the swap in the spring, so I have a few months to sort out what I'm going to do, I might end up building an entire new motor to drop in it if it's going too be too much mix and match, the cars are my current and future DD so I can't have them both torn apart for weeks while I build a motor for it. I apologize for coming off like some idiot kid (even though I'm 24, so I kinda am), I'm new to the Subaru thing (and this is my first engine swap).

[cj91legss]

I would hit up a junk yard for a long block from a "wrecked" legacy. There's a really good chance that engine is still good.

[wtdash]

HI,
This type of swap is also covered (ad infinitum) over on the ultimatesubaru.org site and why it's not advised.

Quick answer: From what you're describing you have a good EJ251, correct? SELL IT and buy a '92-'94 EJ22e, as the '90-'91 had a few early year quirks. Those 251 sell for about twice of an EJ22 (due to the HG and then subsequent rod bearing failures).

More info:
You're dealing w/2 different although related engines.

The '90-'98 EJ22 was a Phase 1 (minor changes over the years in '96 and '97). The '99+ EJ22 and EJ25 were Phase 2....look up more info Wikipedia under EJ Series engines. (The '99 Legacy EJ25D was hybrid - Phase 2 block w/ left-over Phase 1 heads and electronics). The 251 has a different intake manifold (IM) bolt pattern so you CAN'T swap IM's. The electronics are different and the engine wiring harness (that runs under the IM) connects @ the back (I think) as does the '96; your '93 connects by the battery.

'96 was a transition year - single port heads but still the HLA's for the valves. ...but I digress. It'll bolt up and is the best option for the '93. You can use the '96 IM, but must be w/a '93 harness and throttle body. Get a new single-port Y-pipe (exhaust header). The '95-'98 EJ22 w/Automatics had the EGR; 5-speeds nada.

The EJ22 was a solid engine - for the most part. As stated if you find one in the JY and body is trashed, the engine is likely salvageable..

But.....there is a guy on here...or used to be....who made one of these phase 2 engines sorta/kinda/maybe work......username is MikeyMeyagi - it was drivable, @ least. The guy was a magician w/cars, so there may have been more to it than is listed.

GL,
TD