Bore out a 9 to a 12?

[dmoulton]

I've just purchased an '03 XB9, and since it's the same block, am thinking about boring it out to the larger 1203cc's. What all would be involved besides new pistons and heads? Can I use the same Jardine exhaust (I know next to nothing about exhaust systems...)? Any and all help and advice would be appreciated. Thanks!

 

[midlifecrisis]

Actually, the 1203 is a STROKED 984. So you would need to start off with a new crankshaft.

 

[dmoulton]

Stroked...so same bore size, just longer stroke? Implying new crank and connecting rods? What about heads? It seems like more volume in the cylinder would need more intake/exhaust capability. I'm obviously new to this (used to working on cars), so help!!

 

[LeFox]

you'll need case boring, cylinders, pistons, seal rings and gaskets.
the jardine is no problem, but mapping of ecm will be needed.

axtell has a nice kit.