more or less as title says, is there and if so wot are the differences between and how to tell between the v5 wrx, sti and sti ra blocks.

 

assuming all version 5 then they are all the same blocks

 

so if all same blocks is there a way of telling that the internals are sti without splitting block, it is just a short block so no pistons are visible, also is there any diff between internals on sti and sti ra?

 

You can remove one of the Gudgeon Pin access plugs,and will a very small mirror and a torch have a look at the underside of the piston.
STi's will have a smooth underside and stamped HF,2,3(forged) - whereas non STi's will have cross hatching to signify standard cast pistons.

Mick

 

thanks i will have a look asap, i take it then that the ra version doesnt differ from the sti then?

 

Bottom end is the same

 

av just realised what u sed merlin, gudgeon pin access plug, a dnt quite understand what u mean, i also dont want to split the crank case/block.

 

No need to split the Block Halfs - see pic







Mick

 

top stuff merlin, thanks very much!

 

No Probs mate - the Pistons below are Vers.4 Standard Cast (left)
and HF Forged STi Piston on the right.