I have found a sti shell for cheap money and a V3 wrx block. I am looking at putting the block in the sti shell and making some quick cash. It still has everything complete in the car and all sti parts. Will this be easy to do seeing the V3 and V4 are very similar? I realise this block doesnt have forged pistions like the sti block will but will this project be just a straight bolt on?
All help is very much appreciated

 

Should be as long as the coil pack is in the centre of the inlet manifold it's basically the same engine minus the forged pistons as you say, although i'm pretty sure the WRX cams are different from the STI ones, so there will be some cam timing issues, you might need the WRX ecu to make sure everything is bang, also number of catalytic converters may be an issue.

It can be done, but best to install an esl daughter board and have a custom map once installed, which would add a fair few quid to the job, I think you'd be better off just putting another STI v4 engine in it, then you won't have the expense of mapping.

Send Kwik on here a pm, he has done something similar so will know what needs to be done to get it running right.