Will the heads from a 1999 Legacy Anniversary Edition work on a 1996 Legacy Outback Wagon?  They look the same but the plug wire port shape is different on the 99 so hence the question.

 

Thanks

They will physically fit, but the combustion chamber volume is much smaller on the 97-99 25d heads than the 96 version. You'd be creating a fairly high compression engine that might not run very well with the 96 ecu.

yes.  there are two style valve covers and hence valve cover gaskets, so just get the entire head/cam/valve cover assembly which is easy since those other components have little value anyway.

The reason I am doing this is the old heads from the 96 have bad valves - one burnt off or it is missing a chunk.  No compression is the result.   So, I have the 99 heads which were already machined, just trying to save some money.  If I use the old head, I'm assuming it would need to get it machined plus have do the the valves.   If I do the valves I'm assuming I would need to have the seats lapped or what ever they do to match the new valves?

 

Any advice would be appreciated.  Based on the two responses, I'm not sure if I should use the 99 head.

 

Thanks!

Sounds like the heads you have are not a drop in.

 

Find a good head that matches the one missing a valve. Or replace and lap the valves. Machine the Headgasket surface.

The end result will be 10.5:1 compression, up from 9.5:1 of the stock 96 engine. It would definitely require premium unleaded fuel, and be a decent bit more powerful. But probably not what you're looking for in a daily driver.

Any idea if the valves in the (96-99)heads would be the same?  I know I can pull them out and compare - just curious if anyone would know off the top.  Also, what is the recommended prep on the block surface.  I use a sharp havy duty razor blade perpendicular to the surface and scraped off the gasket residue and wiped with brake clean.  Do I need to use scotch brite or something similar?

 

Thanks

They are not, the 96 valves are shorter because of the hla lifter buckets. I don't know offhand if anyone still sells the 96 specific valves.

Intake, 13201AA252 MSRP $17.78 ea, currently 76 in US supply warehouses

Exhaust, 13202AA510 MSRP $25.88 ea, 69 available

Another option might be to buy a headgasket that's a little bit thicker?  Cometic or Six Star used to provide various thickness EJ25 headgaskets.  

Since you already need to buy headgaskets that might mitigate costs and bring compression back down?

When you start messing with head gasket thicknesses on overhead cam engines you are also playing with the cam timing. For instance many people use 97-99 ej25d heads on ej22e shortblocks for a budget low compression engine to turbo. They use 1.5mm thickness headgaskets instead of the 1.3mm thick ej25d gasket and it is enough to throw the cam timing slightly off. Most show about half a tooth out of time on the LH bank after the belt is tensioned and rotated a few times.

how do they run?

 

I used thicker gaskets years ago and didn't notice issues - i feel like it was on Phase II EJ25 heads on a Phase I EJ25 block....but might be wrong, it was quite awhile ago.

Most run pretty well, but there is a common complaint with almost all of them of a slight misfire feeling at idle and part throttle. Not enough to trigger a cel, but enough to feel.

 

Going from 1.3mm to 1.5mm also doesn't affect the combustion ratio that much, it drops it to 10.3:1 from 10.5:1. To get this particular hybrid back down into the 9.7:1 figure that the 97-99 25d has would require a 2mm head gasket, and at that point you're going to have issues with the timing belt being too tight to last very long.

 a 2mm head gasket

 

just what an EJ25D needs - an ultra exotic limit pushing headgasket...

Well, guess I'm gonna buy a valve, lap the valves/seats, news guide seals in and let er go.  No comments on clean-up for the block side of things?  Suggestions for getting the carbon build off?  The valves and the top of the pistons look nasty.

 

Thanks

Edited November 1, 20169 yr by xyzb

Sounds like the 99 heads are 2.2 phase 2 heads and I dont think those would work anyways. I could be wrong though

I check the head surface for flatness - it is in spec <.002 .  The head gaskets were replaced several years ago by the previous owner.  There are some light marks from the previous gasket.   Is there a need to resurface it?  Do you guys suggest coating the new MLS with Permatex Copper spray?

 

Thanks

Do NOT coat it. Buy good gaskets. I have had good luck with 6 star head gaskets, but they are expensive

Always resurface is what I have done, and seen /read. You want to get rid of the impressions of the old fire rings.

i always resurface - i don't even care or measure for flatness because that's not the only point.  i want it clean and proper RA finish on an engine that's already prone to failing headgaskets with the OEM factory installed brand new parts.

 

you still have a great chance and high success rates without resurfacing too if you're in a bind for some reason, though you seem more than capable of just doing it yourself anyway:

http://www.ultimatesubaru.org/forum/topic/122588-diy-head-resurfacing-or-post-apocalyptic-machine-shop-techniques/

Newbie on the valve stuff - looking for guidance. This car is a winter beater, so I would prefer to not spend a bunch and use it as a learning project. Take a look at the exhaust valves. They are full of carbon, not sure if they are worth lapping or just buy new and try to lap the seats? I bought Permatex lapping compound and there is mention of different grits to start and finish with. I'm assuming these can be purchase or not needed? The intake valvues look good. Also, recommended solvent to clean them?

Thanks!

 

Exhaust seat with some lapping:

 

 

Intake:

 

Exhuast valves - no lapping and some lapping:

 

Edited November 3, 20169 yr by xyzb

Thanks for all the info!  Just curious about the block side of things.   I pulled the head with the motor in the car.  How is the surface prepped and what would you use to ensure that the surface is good to go to install the new gasket?

 

Thanks!