V4 heads on 89 block

[Ryan]

I'm putting V4 STi heads on a '89 closed deck block. Getting new forged pistons, are they all the same or are V4 pistons different? Apart from needing to clear the oil squirters.

[Guest]

were you drinking when you wrote that?

-smurff

[Ryan]

Haha just re-read it

[dubbedup]

[Shale]

Pistons different from what?

Easy way to group Imprezas.

Mechanical/exterior: v1&2, v3&4, v5&6. The differences in general tend to be minimal WITHIN the group, but QUITE different between the groups.

Interior: v1,2,3 and v4,5,6.

The thing that stops the 20K heads from fitting a 20G shortblock is the pistons. Put the appropriate pistons in and that's one worry solved

^ninja edit. Disclaimer: simplistic, generalised view.

[nt_a_foz]

Id talk to someone that KNOWS rather than shale.....

Its pretty serious if you fuck it up lol...

Talk to someone thats built a few motors or knows them well and youl be sweet

[Koom]

Usually when you're buying off the shelf pistons for EJ20's there's pre-98 and post-98. I used pre-98 with my V3 STI heads, I'd guess V4 is the same as the change most likely occured with V5.

[Joker]

is CD block with TT heads...

[nt_a_foz]

 Koom said:

Usually when you're buying off the shelf pistons for EJ20's there's pre-98 and post-98. I used pre-98 with my V3 STI heads, I'd guess V4 is the same as the change most likely occured with V5.

Yeah i think your right there Koom from what iv been told its v5 that had the change

[Solja]

im running a closed deck with v3 heads and post 98 wiseco forged pistons, seems to go well but it upped the compression ratio to 8:5:1

[Ryan]

Yeah I ended up getting some pre-98 Mahle pistons after talking to Kent at SpeedSource. He reckons I should try and keep my compression ratio at the low 8's.