EJ25 info ????

[sammydafish]

I have a 98 Legacy Wagon at my shop with an EJ25. It needs an engine. Calling up the rebuilders and yards I usualy deal with everyone says that year is special and they don't have one, can't get one or want 5k to build one. Now I know that the long block can only be so special the way Subaru does things, so what else will fit? I know there is this change with phase 1 and phase 2 EJ25s. The phase 1s had the head gasket problems, done a few of those head jobs. The question is, what years/models got these engines and what's different about them? I've got to imagine any other EJ25 could easily be made to fit, but I'd like to know the internal and external diferences before I source an engine. So where can I get this info? There has got to be a website that lists this kinda stuff, but I have yet to find it.

If it were my own car I'd build all kindsa crazy stuff, but for a customer I need to be able to source a whole long block that I can pretty much just drop in. I expect to swap the manifolds.

[Matt Monson]

'98 is kind of unique because the '96-97 DOHC Ej25's had HLA's while the '98 has shim under bucket heads. But a '99 DOHC would work. They were found on Legacy GT's, Outbacks, and Foresters. They are actually usually phase II blocks, but with phase II heads. There are very minor differences in piston dish between a '98 and a '99, but not enough to matter.

Also, any '96-99 shortblock could be mated to the customer's heads without a significant change in CR. You might go that route if you get desperate, unless this is a popped timing belt with bent valves repair, or something along those lines. For someone looking for performance, a phase II MY00-03 block would be an option, but this raises the CR up into the 11's and would require premium fuel. Probably not what this customer wants...

[Project_Legacy]

isnt there a difference with dual port exhuast and single port also? if the customer reuses the same heads he has it shouldnt be a problem then. you probably alrdy know that tho.

[206er]

single port is an ej22 deal.

[Project_Legacy]

o shoot haha. sorry about that then. i thought it was the 2.5's. disregard my post plz!

[sammydafish]

They are actually usually phase II blocks, but with phase II heads.

Did you mean they are really Phase I blocks with Phase II heads?

So phase I is 96-99 and Phase II is 00-30 (04?)

it seems that some time in 99 the EJ25 went to 10:1 compression and I assume this is the change in piston shape that you mention. Is there are way to tell between the 9.7:1 compression engines and the 10:1 compression engines from the exterior? some type of marking or something?

if it's a 10:1 compression engine is it a phase II? maybe the Phase II was a mid year change in 99 going into 00?


thanks for the help this far, so far the best info I can find is here
http://www.wac.addr.com/auto/obs/turbo/ejcalcs.html

[napphappy]

Im not sure what Matt said was 100% accurate.

The 96 2.5(found in Outback and GT) uses Dohc HLA Heads and uses the same Lifter buckets as the 3.3 SVX.

The 97-98 2.5 Legacy, 98 2.5 Impreza and Forester, use Shim over bucket solid lifters that have a larger diameter than the earlier heads.

Like Matt said in 99 the 2.5 Impreza and Forrester was Phase II but unique in that it had a MAF.
The 99 Legacy 2.5 was basically a Phase II Block with Phase I DOHC Shim Over Bucket Heads.

All Info is from expirence and or the
Boxer Engine
Series Module
Module 104

[napphappy]

All 97-99 2.5s were 9.7:1
In 2000 All 2.5 were Phase II at 10:1

Im not sure how to tell externally if it is 9.7 or 10:1
My guess would be. If the Phase II engine has a MAP and a MAF its a 9.7:1
If it only has a MAP its 10:1

[DLC]

What Matt was saying is that in 99, they started putting Phase II blocks in the Legacy, with Phase I DOHC heads, after the Phase I blocks had dried up. You may notice that the Impreza went Phase II in 99, leaving the Legacy the leftovers. Hybridizing the EJ25 was done by Subaru before anyone

[Matt Monson]

'97 appears to have been a transition year on the heads then. I have seen '97 heads with HLA's. Kind of the same thing DLC was talking about with the blocks.

As for the '99 bottom ends? When they started using the phase II bottom ends and rods, they made a square cut out piston with 1mm less dish than the previous phase I EJ25's. This was to keep the CR unchanged, since they also moved the wrist pin height and the pistons didn't come up above the deck height as much. It was a unique year. Some '99's were phase I and some were phase II.

In MY00, all the EJ25 bottom ends moved to the pistons with the little valve cut outs, instead of the "box" in the dish...

[Matt Monson]

oh, and MAF versus MAP has nothing to do with any of it...

[napphappy]

What I was trying to say is that in 99 the Phase II 2.5 had a MAF which is the only year to have one. So it may make sense that they switched to MAP only when they made the change to 10:1. Thus giving a possible external clue as to whats inside.

[Matt Monson]

What I was trying to say is that in 99 the Phase II 2.5 had a MAF which is the only year to have one. So it may make sense that they switched to MAP only when they made the change to 10:1. Thus giving a possible external clue as to whats inside.

I think that is overly complicating things. The '99 SOHC Ej25 used in the RS was the only SOHC Ej25 to use a MAF, but if it has SOHC heads you already know that it's a phase II engine. Beyond that, ALL DOHC Ej25's were on MAF based cars, so when he's shopping for an engine for his customer, every engine he sees will be a MAF engine.

The best external tell for a phase II bottom end is an 8 bolt bell housing versus a 4 bolt bell housing. Now, there were 4 bolt phase II bottom ends in some '99 Legacies and Outback. But really, that shouldn't matter either.

I think the thing that is being missed is that Phase II ONLY designates the placement of the thrust bearing in the case. The phase II put it on the flywheel end, while phase I had it centered in the case. As I mentioned above, there were phase II blocks that used the phase I style of piston with the square dish in '99 only, and only in Outbacks, GT's and Foresters. If one were to open up a '99 RS Ej25, they would find the later style pistons with the little valve cutouts. That's going to ultimately determine the CR, and using ANY DOHC Ej25 shouldn't be a problem for this particular application. Only, if a shortblock is acquired, and mated to the customer's heads, does any of this become relavent.

One last thing. I inquired with a friend who works for CCR about the '97 heads. According to them, the official specification for '97 is shim over bucket heads, though they too have seen cases of HLA's used in a few engines. It's pretty common for Subaru to use up all their spare parts from a previous design before rolling the new one into full production, so it's likely that '97's with HLA's were made in Sept or Oct. of '96 when MY97 production started. It might also have to do with cars made stateside versus in Japan, but that's just a guess. As has been discussed here before, there are definitely differences in early Legacies depending on their country of origin, even though they were US models...

[sammydafish]

thanks a lot for the info guys. Been a lot of help. It seems that dispite the minute differences, any DOHC EJ25 should work (I'd get a long block). This thing died because it blew the HG and ended up with a crankcase full of water and was drivin like that for months. The owner would be pretty dissapointed if that happened again, so it looks like I have two choices. Get an early motor and put the updated gaskets on it, or get a motor that I'm sure is a newer phase II. If I pick up an long block with 10:1 compression, whats the chances it might cause an issue with throwing an emissions code? Even fuel shouldn't be a problem since newer scoobs can run on 87 and are all 10:1. I've got to imagine it should only help fuel economy. In theory as the EGR should still work the same and save it from emissions problems of higher compression. Higher compression helps every other form of emissions other than NOx, so it shouldn't throw codes, that is, unless there's something that I'm not thinking about. It's really not that drastic a change in compression anyway. Is there a downside?

[Matt Monson]

No. Just make sure it isn't a SOHC Ej25 and you are fine. There's things like EGR and external IAC on the DOHC Ej25 that aren't on the SOHC models...

[sammydafish]

so there's one bit of info that I guess was missed in all this. Subaru doesn't make the EJ25 in a NA DOHC motor after 99. All the NA EJ25s are SOHC and the DOHC are turbos. Is this only true in the US? Are there DOHC NA EJ25s in Japan or something?

I don't really want to have to do a HG on a used engine I get and I don't want to put in an engine only to have the customer come back in 6 months with a blown head gasket since if it hasn't already been done, it's inevitable that it'll happen.