18 replies to this topic

[Soop]

DOHC pull down.

This is a EJ25D head off an 1998 BD9 RX Liberty.
Quiet obviously this is the top of the head, in the center you can see spark plug reliefs. On top is the outlet for the crank case vent, this is were the a vacuum hose attaches too before running to the intake pipework.

Here are the exhaust ports. Nothing much to know really, this is were the exhaust manifold bolts up to. You can see that it says "Right hand, Naturally aspirated" on the alloy casting .

This is simply the inside of the cam cover.

Here are the cams, two per head. One for exhaust and one for intake. The cam shaft at the bottom of the picture is the exhaust cam. This particular head is missing two cam retainers, as i snapped them off in the making of this thread. Dodgy mechanics using over sized bolts.

This image shows the cams removed. Also removed are the valve buckets and shims. This particular type of head uses a shim over bucket design. What you can see remaining is the valve spring retainers.
I don't have the tools to safely remove the valves so for this thread they stay put.

What you can see here is the combustion chamber portion of the heads. This is were all your power is made. Here you you can see the valve faces, this is the portion that is over sized when the head is ported and larger valves installed. Some race cars also have each dome of the head volume matched so that each cylinder is running equally efficient.

Here is everything (baring valves and valve springs.) layed out for you too see .

So there you have it, a Subaru DOHC in pieces. I know its short and quiet basic, but you now know the major components in you cars cylinder head.

Cheers, Paul.

[XXB4XX]

Awesome stuff Paul, and may I add, God damn, Subaru boxer engines are the most fuggliest things I have ever seen.

[twinturbosubaru]

Awesome stuff Paul,

and may I add, God damn, Subaru boxer engines are the most fuggliest things I have ever seen.

Yes but they go well :-)

[Blaeven]

isn't the 2.5 gen2 refered to as a BD9?? i thought 2.2 was BD7 jap spec: 1.8 or 2.0 was BD5 (not sure about this one) 1.6 was BD3

[Soop]

Correct. Edited accordingly. BD5 is EJ20

[Blaeven]

what is the BD5?? 2.0 or 1.8??

[Not Marv]

Keep the fuel rails off that 25D as you should be able to bolt MY99/00 440cc WRX yellow top injectors into them, and then those rails should bolt straight to any MY89-96 EJ20G head/intake manifold...

[Mav]

nice post man, these threads - helpful for ppl starting out

[Jeff]

Good Stuff Paul. I can learn a lot from you by the looks of it

[N/A_EJ22]

top right up mate. out of curiosity what are you using this motor for? sorry if u rote it in the thread. cheers ash

[Soop]

These heads were of an EJ25D that had a spun bearing. The heads arent being used for anything. The block has its purpose...

[N/A_EJ22]

..............that purpose being for the wagon?

[Soop]

No, Wagon getting an ej22. Quit whoreing.

[Evil_VZ-T]

I wish i had the space and tools to pull down heads. Looks like alot of fun and a good way to learn.

[Soop]

It doesn't take much space, i just used the outside dinning setting. Mum had a whinge, i just told her to go back to eating the chocolate i bought last night.

[jak4cars]

soo soop, are you planning to port and polish up the ports and polsih the chambers? and what made you take it off in tha first place? jst outta curiosity and i really wanna no how do you change the plugs while its on the car? i had to do it once and i couldn't! i gave it to someone else to do it and it took them an hour!!! cheers, jack

[Soop]

Nothing is getting done with these heads. They're POS EJ25D heads. You use a swivel joint on a ratchet to get to the plugs. I pulled the whole engine apart.

[jak4cars]

thanks pullin it apart just for fun aye, cool