I am a complete idiot when comes to subaru engines which hopefully I can get some information here..

As my STI just hit 75k miles. I am thinking to re-build it into a 2.5lt Stroker(if theres one), can anybody tell me if its worth while? Job involved? Part and labour? where to get it done etc. any information will be very much appreciated.

The car is 54reg 2.0 STI

 

Dont you meen a 2.1 stroker?

 

2.5 not possible then??

 

Almost certainly not within an EJ20 case, and definitely not off the shelf. Even if it could be done it'd be a very big money custom build and the results wouldn't represent a worthwhile return on investment given how many off the shelf options there are. You'd need 94mm stroke to sweep 2.5 litres with the standard pistons. So the answer your question re. whether this plan would be worthwhile's a nice round no.

As has been said you can buy 2.1 stroker kits off the shelf, and plenty more options if you want to go larger displacement, the easiest of which is probably a 2.5 STi short engine.

To be honest tho, in the absence of any other information it sounds like you're going about this the wrong way round. 75 thousand miles isn't that much on these engines so on the face of it there's probably no reason to rebuild it at all - unless you want to do a big power build and fit new internals.

Sounds a bit like you've settled on the idea of wanting a "2.5 stroker" without first working out why you want it and what sort of power you want it to develop afterwards. If you give us more of an idea what you want out of your car and how much you have to spend to get it, it'll be easier to advise you.

 

you can have your engine coverted to a 2.5,but you need to have your block bored and fitted with new liners to suite the 2.5 pistons.then all the other bits such as 2.5l pistons,crank.mine is a 2.0l cdb with the steel top hat liners and forged internals,but you dont have to go with a cdb if you are having steel liners,the block you have should be ok.

 

i was quoted 5-600 for the block modified, 2.0-2.5 on a cdb, sep engineerers in kegworth derby, then youll need the internals, they will set you back close to 2k, phil.