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Discussion Starter #1
diy turbo build 2000 ej22. valve stem seals are shot and ive been considering picking up some ej251 heads. was wondering if anyone has had any issues running the oe ej22 head gaskets. or should I run thicker hgs, ej251 head gaskets .040" ej22 head gaskets .030" I believe not positive.
 

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95/99 Brighton STi
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I don't think you can run EJ25 heads on a EJ22 block because the head bore won't match the cylinder bore therefore your HG's won't seal correctly. I'm not 100% sure but that's my assumption.

In the case that I'm wrong, I would go with as a thick a HG as possible if you're boosting. Generally, you buy the HG according to the block. So in this case, you'd want a think EJ22 HG.

IMO, I would just replace the valve seals in your head.
 

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headgaskets can only match the block, thickness determines static compression ratio, though swapping heads in and of itself can and will alter compression ratio as well

as mentioned if the spherical area (combustion chamber) of the head is larger than the cylinder, it's a no go. The area can be smaller (within reason, such as the EJ20 heads/EJ257 blocks that are popular) though not ideal because of the quench area differences (machining fixes it, the necessity of which is determined by the build/goals)
 

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There no real point to this swap, the combination chambers are the same size, all you'll gain is an extra exhaust port per head.
 

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Discussion Starter #7
^^your saying the cobustion chamber on the ej251 heads are the same size as the ej22. i was under the impression the ej251 heads have a bigger combustion chamber(hence bigger bore) thus lowering compression, and upping the boost to compensate.
 

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Discussion Starter #8
im not worried about changing my exhaust manifold to dual port. i just want to lower compression so i can push more than the 4.5psi of boost i am now.
 

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Phase 1 ej22e is the one that gets the benefit of the lower compression by the head swaps, the phase 2 sohc heads are basically the same.
 

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98 impreza coupe, 03 WRX wagon
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Phase 1 ej22e is the one that gets the benefit of the lower compression by the head swaps, the phase 2 sohc heads are basically the same.
That being said, if the heads are basically the same they should match up right? I mean pII ej22 block to pII ej25 heads. You have to figure, if the builder is planning to boost then itll be easier to source a dual-port header for a turbo than it would be a single-port. We dont all have the means to have custom manifolds made :(
 

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Discussion Starter #11
the car is already boosted with single port headers im just looking to add boost. does the same go for ej25d heads, or are they only dueable on the p1 ej22.
 

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98 impreza coupe, 03 WRX wagon
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the car is already boosted with single port headers im just looking to add boost. does the same go for ej25d heads, or are they only dueable on the p1 ej22.
Any chance I can get a peek at your your single port header setup for the tubo? Did you have it custom made or did you find it somewhere??
 

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Discussion Starter #14 (Edited)
so what i did was use the stock exhaust manifold (headers) and had subachad fab me up a up and down pipe. his up and down pipe are meant to bolt right up to your single port headers. he also makes the turbo flange to fit a td04 turbo. i pieced all my parts together from craigslist only thing that was new was the up and down pipe and i had an exhaust shop mate the down pipe to a mid pipe section i got out of a 99 impreza that had a 3" exhaust. the pic i posted is the only one i have at the moment, hope it helps let me know if you have any other questions.
 

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98 impreza coupe, 03 WRX wagon
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Hey man I cant knock it I like the idea. Wish I could manage some custom fab around here. thats really my whole base reason for the frankenmotor, to have the turbo manifold. Good to see someone took the time to do what I cant :)
 

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Discussion Starter #17
find subachad hes based out of vegas he has been fabbing up and down pipes for a while. ordered mine and had them the following week.
 

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98 impreza coupe, 03 WRX wagon
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find subachad hes based out of vegas he has been fabbing up and down pipes for a while. ordered mine and had them the following week.
As much as this does intrigue me, I figure theres no way Im gonna slap a turbo onto a motor with over 100k on it without taking care of stuff such as head gaskets and timing. Which will involve pulling the heads (gaskets will at least) and if I already have a 2.2 and a 2.5 sitting in a garage, that means no extra cost on that front.

But just for the sake of conversation, how much did the custom up and down pipes cost when you get them??

And if Im only aiming for about 8lbs of boost, should I have to worry about changing out internals?? Or will stock guts hold up?
 

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Discussion Starter #19
i paid about $450 for the up and down pipe, definitly the priciest part for the turbo build. as far as internals its all stock the 2.2 can run low amounts of boost without harm. at the moment im running 5psi no problem but will be changing my wastegate spring to push about 7-8psi.
 

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MY99 GF4 EJ227 JDM 6spd
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Take your head gasket, mark the chambers, and removed material from the sides of the chambers. This will help with flow and drop your cr some. I do this with WRX heads going onto 2.5L blocks. A simple chamber flare.
 
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