After a crank failure recently in my V5 STi classic i decided to replace the bottom end with a stronger newage STi version,i managed to secure a 21k low mileage JDM twinscroll STi 8/9 bottom end from a friend of mine.i have read that the twinscroll engine has differences to the JDM and UK STi engines,does anyone know what the actual differences are and possible benifits/disadvantages of a twinscroll engine.

 

Think its just the heads and cams glen,the jdm engines use big port avcs heads and hotter cams,bottom end is same as far as im aware,apart from the sump.

 

AFAIK the JDM twinscrolls also have a different turbo (VF37?) and downpipe, and as a result faster spool up and better top end performance. Can't say this for certain though as I'm not an engine specialist.
Bottom end - not sure of the differences if any, as per H4RDY's post.

Suspect Midlife or Splitpin would be able to tell you, or David @ API to name a few names.

 

Yeah the sump,oil pick up and baffle plate are all different pete,they also have an uprated v9 nitrided crossdrilled crank aswell mate,bin reading loads the last few days and just wanted some more info that maybe i havnt come across yet.

 

Nitrade crank on the jdm