I'm wanting to turbo my 960 and ill be swapping in either a 2.8L T6 or a 2.9L N/A. I've done a little searching and came up with nothing for lower compression pistons for the 2.9. Will the S60R pistons fit in the 2.9L RN engine? They're both 83mm bores so I'd assume they would but I want to be sure. Or should I just build on the T6?

 

you'd need to consider the rods when using pistons from another model. The 2002 to 2006 S80 T6 and XC90 T6 use the turbo version of the 2.9's modular engine so those may be the best fit for 8.5 compression. (both are 83mm bore x 90mm stroke engines).

 

would there be any advantage in swapping those internal parts or would it be easier to swap in the whole T6 engine? I'm not sure how much is different between the wiring harnesses of the N and RN engines

 

The T6 engine does have some differences - specifically the VVT gear set up which is controlled by the ECU. Many turbo designed engines also have oil jets to cool the underside of the pistons, not sure if the NAs have that.

 

so then if i swap the engine the T6 harness should go with it? I don't really care about VVT, I dont think the T6 has CVVT but i could be wrong.

 

yes if you swap engines you'd want to use the harness and ECU from the replacement. That may be more complex than it sounds due to tie ins with the immobilizer etc so that's something worth researching.

 

how would that affect the AW30-40? would i need to reprogram that or would it be easier to manual swap it? i know there's a site somewhere that sells adapter plates for whiteblock bellhousings.