hi guys, need someone who knows their stuff with heads as i need to know the difference between the version 1/2 heads and the version 3/4 heads ?

am i right in saying that the v1/2 head have the same casting and use single coils bolted to spark plug hole and that hole is square ? and look like this



and the version 3/4 heads have no coil pack where spark plug hole is and coil pack is mounted on manifold and heads look like this



then question is what dose it take to fit v3/4 heads to a v1/2 subaru ? be it a wrx or an sti,

can u use the v1/2 manifold on the 3/4 heads and also use the v1/2 coils on the v3/4 heads

any help would be great guys

 

Mick, your services are required!...

 

hi there Im sure the inlet manifold mountings are different??

 

just trying to clear something up as someone said that the bolt pattern for v1/2/3/4 are all the same for inlet manifold and that you can just bolt the v1/v2 single coils to the v3/4 heads all u need to do is change the rocker covers from v1/2 and bolt them to the 3/4 heads

i said that if running v3/4 heads in a v1/2 subaru you would need to change manifold to the v3/4 and also run the single coil pack which would need to be wired but not hard to do

so thanks for all the help we get on this guys

 

one for the 22b guys, are you on that forum

jim

 

Im the one who said it so ive thrown a spanner in the works
To my knowledge i now know the plug hole's differ so +1 to for that one
But i am sure the manifolds are interchagable as inlet manifold gaskets are listed as 92-98 or ver1-4.
Im pretty sure the spark source is ok to stay as multi coil's as Jef's car is running ver 3 heads on ver 1 car and appears to still have multi coil's as there is no sign of a coil pack/lead's which leads me to believe that they will fit ok.

 

A phase 1 inlet mani will fit v3 heads fine, i used coil packs on my old 2.2 build with v3 heads by putting v1 rocker covers on v3 heads, on my current build i will also have v3/4 heads but will be using a v1 loom/car/manifold so will just swop the rockers cover again to use the coil packs.

 

so the pic at top is version 1/2 head casting,

bottom pic is version 3/4 head casting,

the manifold from either 1,2,3,4 will all fit both head castings,

bit I'm now stuck with is the coils from the v1/2 you say that if you change the v3/4 rocker cover to the v1/2 rocker the coil pack fits but as stated the plug holes in rockers are different shape so wouldn't the oval head and square rocker not be miss matched and cause leakes etc..?

 

That's what I was thinking

 

Should go straight on manifold bolt holes look the same to me

 

v1 2 3 4 heads are all interchangable no need to change rocker cover i have v3/4 heads on my v 1/2 and no problems just use your original inlet and everything will fit.

 

as above, all interchangeable

 

What do you do about coil pack? as v3 is
leads? so the coil pack wont fit in the hole?? any ideas??

thanks

 

coil pack should fit fine ? i used v3 heads on my build and the early coil packs fitted fine as do the newage ones im running now

 

hmmm ok mate ill have 2 have a look again but didnt seem 2 want to fit for me?

cheers

 

your not using legacy heads are you ? i 'think' they have different rocker covers