I wanna know if C1J/C2J/C3J (ie the 1397cc reno lumps) all use the same head?

GTT and non-GTT basically?

Have same valve sizes, but didnt know if the GTT ones had some other shit that made em different...

Id ask on RTOC but need to pay to go on there...

 

I thought an answer would be too much to hope for

 

different shaped combustion chamber I think which affects the compression ratio.
i know the turbo & non turbo engines are not interchangeable despite looking the same from the outside. go well though for a while as my m8 found out a few years ago

 

turbo heads have a knock sensor

 

so they deffo got diff combustion chamber sizes?

i wondered that, if was piston or head or both that affected compression on em...