THE ROVER SD1 FORUM

kiwi_sd1 · Posted: Sun Feb 10, 2008 9:59 am Post subject: Compression Ratio

Hi all, just out of interest, how is the higher compression ratio achieved in the v8 EFI cars? If I understand correctly, the carb version has a lower ratio, and so if the cc rating is the same then it can't be crank difference...are the pistons higher, or is it in the head shape?

rover v8 · SD1 User Joined: 27 Feb 2007 Posts: 103 Location: Finland

kiwi_sd1 wrote:

Hi all, just out of interest, how is the higher compression ratio achieved in the v8 EFI cars? If I understand correctly, the carb version has a lower ratio, and so if the cc rating is the same then it can't be crank difference...are the pistons higher, or is it in the head shape?

Also EFI has got low comp pistons.. I think all vitesses and VDP efis are only 9.75Cr and Range Rover efi and carb engines are 8.13 or 9.35Cr.
Older P6 Rover has got 10.5Cr.. Very Happy

Only difference is piston dish/cc

_________________
Timo..

v8man1 · SD1 User Joined: 01 Mar 2007 Posts: 149 Location: kent

rover v8 wrote:

kiwi_sd1 wrote:

Hi all, just out of interest, how is the higher compression ratio achieved in the v8 EFI cars? If I understand correctly, the carb version has a lower ratio, and so if the cc rating is the same then it can't be crank difference...are the pistons higher, or is it in the head shape?

Also EFI has got low comp pistons.. I think all vitesses and VDP efis are only 9.75Cr and Range Rover efi and carb engines are 8.13 or 9.35Cr.
Older P6 Rover has got 10.5Cr.. Very Happy

Only difference is piston dish/cc

you got it mate!!!!!!!!!!!!!!

_________________
rover tp vitesse my dads old car!!!
discovery 3.9 es,