Hi ive bought some STI 2 cylinder heads t go on my 96 wrx,now i no the cams are different but are the valves ,lifters and the head castings any differnt to what ive all ready got.
cheers pete

 

the valve & cams are different, but the castings are the same

 

thanks dabow i will change the heads then instead of just the cams
cheers pete

 

On the early heads Pre '96 the valves and cams are all the same, whether wrx or STI.

The difference comes in with the lifters:
The V1/2 STI versions had light weight hydraulic lifters approximately 10g lighter, to help stop valve bounce at higher revs.

The V1 RA had under bucket solid shims/lifters(not the same as the V3/4 STI) to stop hydraulic lifter pump up at high revs, and the fact that the shim was under bucket helped stop the shim from falling out if over revved.

The only true upgrade from V1/2 heads is v3/4 STI heads as they have under bucket shims and better profiled cams.

 

if your thinking on changing to a set of sti v4 heads.
check my thread out mate.

im selling a set with every thing needed to put them on too:-

subaru sti v4 heads on eBay (end time 26-Dec-09 01:49:03 GMT)

 

cheers for the info lads look like ive just bought the wrong heads.did wonder why they were so cheap
could a v3/4 sti cams run in a v1/2 head

 

No

 

As above - they will physically fit but wont work correctly as they STi3/4 cams were designed for solid lifters and not hydraulic.


Mick