EZ30 Engine/Head Modifications?

[vristang]

I have a 2001 Outback LL Bean, with the H6.
The heads are the ones with a single merged exhaust port.

The Head Gasket failed and I doing the work myself... slowly :-(

I've been calling shops locally trying to get an idea of how much milling can be done to increase CR, but haven't found many folks who have worked on these engines.
The only guy who would even answer said he wouldn't go more than about .010".

Has anyone done any head work on these heads?
Chambers?
Intake?
Exhaust?

It looks like the exhaust could use some attention, but I would feel a lot better talking to someone who has done it before I turn my heads into scrap.

[vristang]

Also, there is a cross-over pipe that bolts to the back of each head. The pipe runs under the intake, from the left head to the right head. It doesn't connect anywhere else...

It seems this is just for equalizing crankcase pressure in each of the valve covers?


My plan is to utilize these vents for crankcase evacuation to a catch can.
Anyone see any issues with that?

[Reason]

I wouldn't take too much off either. I would get Wiesco to make high compression pistons for you, see if Delta cam has a regrind for your particular cams and get an OBX header, along with a few supporting bits to make sure the engine is reliable. It won't be cheap, but the outcome will be fun.

[vristang]

I wouldn't take too much off either.
Is that because of piston to valve clearance concerns?

Rebuilding the short block isn't an option for me at this point...


Just looking to get a little more out of what I already have...

[vristang]

I'm pasting in some pics from today...
edit - the images were too big, so I just posted links instead

This is where the cross-over tube bolts to the LH head...
http://i156.photobucket.com/albums/t12/ ... LHHead.jpg (http://i156.photobucket.com/albums/t12/vristang/Subaru%20H6%20-%20EZ30/Cross-OverLHHead.jpg)

This is the cross-over tube itself...
http://i156.photobucket.com/albums/t12/ ... erTube.jpg (http://i156.photobucket.com/albums/t12/vristang/Subaru%20H6%20-%20EZ30/Cross-OverTube.jpg)

This is the Exhaust Gasket on the Head...
Seems like some material could be removed???
http://i156.photobucket.com/albums/t12/ ... t-Head.jpg (http://i156.photobucket.com/albums/t12/vristang/Subaru%20H6%20-%20EZ30/ExhaustGasket-Head.jpg)

Chamber 1...
http://i156.photobucket.com/albums/t12/ ... ber-01.jpg (http://i156.photobucket.com/albums/t12/vristang/Subaru%20H6%20-%20EZ30/SubaruChamber-01.jpg)

Chamber 2...
http://i156.photobucket.com/albums/t12/ ... ber-02.jpg (http://i156.photobucket.com/albums/t12/vristang/Subaru%20H6%20-%20EZ30/SubaruChamber-02.jpg)

Chamber 3...
http://i156.photobucket.com/albums/t12/ ... ber-03.jpg (http://i156.photobucket.com/albums/t12/vristang/Subaru%20H6%20-%20EZ30/SubaruChamber-03.jpg)

Chamber 4...
http://i156.photobucket.com/albums/t12/ ... ber-04.jpg (http://i156.photobucket.com/albums/t12/vristang/Subaru%20H6%20-%20EZ30/SubaruChamber-04.jpg)

[vristang]

Sorry the images posted so ginormous....

PM me if you know how to fix...

[Garrison]

I would forgo the catch can.

And depending on the host you chose for your pics, there should be an option for you to resize them.

[vristang]

I would forgo the catch can.
Can I ask why not?

I've pretty good success with running a catch can and eliminating the pcv on my other car...

Working on the images now...

[Garrison]

I didn't really notice any benefit when my engine was naturally aspirated, and you can potentially include the wrong port, which will give your car cancer.

On a boosted car, however it makes great sense (to catch oil blow by).

[vristang]

The intent with eliminating the pcv system is to reduce oil in the intake charge.
If I can get an vac pump on it, it may pick up some power/economy...

The entire intake system was coated with oil, and this is what the chamber looked like on removal of the head...
http://i156.photobucket.com/albums/t12/ ... 3_3712.jpg (http://i156.photobucket.com/albums/t12/vristang/Subaru%20H6%20-%20EZ30/103_3712.jpg)

[Reason]

Try it out and see how it works for you. I always had one on my other cars, I have yet to do it on this one yet, but I do plan on it soon.

[StatGSR]

I wouldn't take too much off either.
Is that because of piston to valve clearance concerns?


Shaving the heads (and playing with head gasket thicknesses) on subarus means you are essentially adjusting the timing, and you are adjusting the timing of each head in a different direction, one retards, one advances (atleast that is what i have always heard). this is typically why it is not recommended to go crazy with head shaving. if you had adjustable cam gears then you could correct it, but thats not all that common for subarus either.