Wrx heads

[Alphius]

The 96 head valvecovers are not compatible with 97-99 heads, as you can see the sparkplug tube is shaped differently. So you must have 96 heads. Further, the head itself will not work well if at all on a 2.2 block since the combustion chamber is made for a larger bore. Somebody must've put a 96 engine in that Forester when the original one blew up. You're going to need to find a set of 97-99 heads.

EDIT: Actually, odd that they aren't HLA. Maybe it's a non-USDM market engine? 4-cam 16-valve markings but shimmed buckets is unusual. If you have the heads off, the 96 heads have a pentroof large bore combustion chamber and less piston dish. The 97-99 heads are a cloverleaf design like an EJ20 and deeper piston dish. You can't safely use the 96 style heads on a small bore engine.

[mike-tracy]

If it was an hla ej25d, those head would be good for matching with an ej255 or ej257

[zeke]

I know that was a bit confusing it not being hla's i haven't had a chance to pull the heads off yet i was going to do that probably on Friday i still need to pull the engine out of my car still been to busy tje last couple of weekends. I know some work has been done to that engine before because the cam seals have a bunch of silicone on them. When i pull the heads I'll get som pics of it all and maybe someone can help identify them. I am going to measure the combustion cambers just to be certain on what my compression ratio is going to und up at.

[zeke]

So I thought that all the hla heads used a rocker setup but I was wrong so I'm guessing that the engine I bought is really a 96 lgt. I still haven't pulled the heads off yet im planning on doing this on Friday. Does anyone know if these heads will drop my compression ratio too low? The other issue i was seeing is that the combustion chamber is the same size as the as the 2.5 pistons if so will this be an issue I just don't want to have wasted money on these parts.

[Alphius]

The combustion chamber is too large if they are 96 heads, you can't use them on a 2.2 bore.

Yeah, the HLA is under the bucket on 96 heads, no rocker arms.

[zeke]

So this is what the 22 head gasket looks like on these heads



So I dont see any issue with the bores and im going to go ahead and use these heads with a stock ej22t head gasket.


I do have another issue while I was pulling off my crank pulley I have pretty bad crank walk. I never noticed it while it was in the car kind of glad that the throw out bearing popped off or I wouldnt have noticed until it might have been too late. I was planning on replacing the main bearing anyway I am going to split the block tomorrow and just hope that my crank isnt screwed up.

[zeke]

not sure why these pics are so big when i upload them

[86BRATMAN]

The other, very large issue, you're going to have using those heads is going to be the 7:1 compression they're going to put you at.

[zeke]

When I put everything into a compression ratio calculator it came out to 7.3:1 I was going to have the heads resurfaced also

[Alphius]

Eh, low CR isn't the end of the world. It isn't optimal for power, torque, mileage or spool time, but it'll run OK.

[PhyrraM]

If you resurface the heads enough to change compression you will likely need to address cam timing too.

Sent from my SM-N900V using Tapatalk

[86BRATMAN]

If you got 7.3 then you used the wrong combustion chamber volume. The 96 25d heads are 56cc.

Actual compression is somewhere are 6.8-6.9:1 with those heads, I rough calc'd it in my head for the above number.

[zeke]

I measured them and it came out to 54cc