hi all,
just a quick 1, what is the noticable difference between the sti v2 and v3 heads, thanks phil.

 

different castings.. everything is different..

difficult to explain without having them in front of you/I to explain.

Usually the version 3 cam covers are smooth but v2 are ribbed.

They should both have under bucket shims if sti.

Simon

 

thanks, what about valve sizes?

 

yes they are probably different but I don't know sizes wihtout going and digging out a set and measuring, sorry

 

i've got a version 1 sti with hydraulic tappets, did the v2 go to solid shim's? or did that start on the 3's

 

then they are not sti heads.. been changed before you got the car..
v1 and 2 are solid

 

Im sure the STi Version 1 ~ 2 and WRX were Hydraulic - the STi having lightweight Hydraulic lifters.
STi Version 2 RA had solid lifters ( top hat inner shims ).
STi Version 3 ~ 4 were as you said, solid lifters.
Some Version 3 ~ 4 V-Limited and Type R had either small outer shims or the regular STi Inner shims.

It's not often you come across an "un-molested" engine due to the age of them now - even with a fresh JDM import, so its a bit of a lottery when the cam covers come off to see whats lurking in there.

Mick

 

thanks for all the info, i have a v2 sti and they have the solid bucket type, i just wanted to see what differences there was between v2-v3 heads as i have some on the way and wanted to know what to look for when they arrive, why can they take more bhp than the v2 heads then?

 

agree.. just checked with someone whom I know bought an original v1 sti a number of years back and it had hydraulic lifters.. so I was wrong they aren#t solid

 

just to throw another small spanner in the works my v1 has smooth cam cover's so i'm thinking it's a bit of a lottery at time and only when you get it all opened up do you know for sure.

 

The shape of the Spark Plug holes will give a clue to what Version heads they are ( but not the valvetrain - ).

Version 1 ~ 2





Version 3 ~ 4






Mick

 

thanks very much for them pics, its easy to spot the differences, ill just look at the plug hole, cheers phil.