Intake Manifold Interchangability

[skyphix]

Depending on what I find...

Will my DOHC intake manifold fit on the SOHC Long block? I'm finding a lot of conflicting info. Figured someone that has had just about every engine in various cars like Fred might be a more reliable source.

I'm also thinking of springing a little more money for an '05+ NA 2.5 so it'd be nice to get the better engine but not have to do the wiring (I'd rather just swap an EJ20 or 255 if I'm going to do wiring).

[Capitalandmotors]

your ej25d bolt holes are different then the newer sohc motors, so they won't line up

the ej25d look like       0      0            <-------  bolt holes
                           0               0

the ej251 or ej253 are like   
                           0     0 0      0

the easy way to change engines is to keep everything the same on the intake manifold, that way all the electronics are retained and no need to alter the wiring.

[skyphix]

So it looks like 25D shortblock or complete would be best for my situation. Guess I'll keep looking.

Thanks for the diagram Fred. What I meant when I said "not have to do the wiring" was use my current intake manifold and sensors so I didn't have to go through the crap involved in changing it over for another NA engine.

So I guess the next question is - will my crap swap over to the 251/253 intake manifolds?

[Capitalandmotors]

i'm not 100% sure. i think it can be done but what i've heard is the cam sproket triggers are different and not interchangable.

are your heads damaged or believe to be leaking(internally) you maybe able to swap blocks with a newer car but i know the newer heads (sohc) will need some convincing to work with your wiring,

i say we throw in a ej22t block since it will mate nicely to your heads and intake. make some up and down pipes similar to my old rs subachad pipes and a boost it, add a piggyback and be happy with it

[skyphix]

You're thinking along the lines of what I am Fred

It all depends on how cheap I can do it and have it be reliable. My heads are shaved (almost 100% sure, headgaskets blew and it seems like every DOHC car that has had the head gaskets go also had the heads shaved). Car runs like crap on 87 and fantastic on 93. Haven't changed the plugs but it doesn't seem like a slower burning fuel that is harder to ignite would make a difference if the plugs are so dead they're causing stumbling. BUT, with the EJ22T block even shaved DOHC heads would give me around or less than 8:1 CR which is perfect for boosting as long as I use the stock dish EJ22T pistons. I'd probably run the thin head gasket just because it'd net me a little more CR to get it closer to 8:1.


If I can have a boosted Forester for the same price as I can have a DOHC EJ25 Forester and have it be close to as reliable, I'm all for it. I know to add ~$600 just in parts for head gaskets and all the bits that go along with a timing belt change. If I could do the whole shebang and have it be reliable for ~$1000 it'd be realistic, though that ~$1000 price tag might not be. Not right away, but nearer than a ~$4000 dollar EJ20T swap.

Thanks for the help, as always,
E