This might also be interesting for people around here,so thought i just post it up.
I recently bought a Used D14Z2 pistons ,ideal for some research
The 96-98 civic EJ9 (D14A4/D14A3) uses the P3Y pistons and they have a stock compression ratio of 9.1 :1.
The 99-00 civic Ej9 (D14Z2/D14Z3/...) uses the PHXG pistons and they are presumed in having 9.2 :1 compression ratio.
When i did my earlier measurements on the P3Y pistons i found this:
Piston pin diameter: 19mm
Compressie height 29.5mm
Piston dish volume: -5.4cc
Totall height: 49.55mm
On the PHXG pistons i found this:
Pistons pin diameter: 19mm
Compressie height: 29.5mm
Piston dish volume: -2.4cc
Totall height : 49.10mm
The PHXG pistons are almost flat top pistons.
This means the 99-00 D14Z engines have a compression ratio of 9.7 :1.All the rest of the parts cylinderhead ,head gasket ,rods are all the same as the earlier D14 engines.One thing i also noticed is that the PHXG pistons are obviously stronger and thicker shaped.This could also mean they can handle much more power then the older P3Y pistons.
I Learned a lot from this ,i hope other people can use this info too
Picture time
![]()
![]()
![]()
![]()
I recently bought a Used D14Z2 pistons ,ideal for some research
The 96-98 civic EJ9 (D14A4/D14A3) uses the P3Y pistons and they have a stock compression ratio of 9.1 :1.
The 99-00 civic Ej9 (D14Z2/D14Z3/...) uses the PHXG pistons and they are presumed in having 9.2 :1 compression ratio.
When i did my earlier measurements on the P3Y pistons i found this:
Piston pin diameter: 19mm
Compressie height 29.5mm
Piston dish volume: -5.4cc
Totall height: 49.55mm
On the PHXG pistons i found this:
Pistons pin diameter: 19mm
Compressie height: 29.5mm
Piston dish volume: -2.4cc
Totall height : 49.10mm
The PHXG pistons are almost flat top pistons.
This means the 99-00 D14Z engines have a compression ratio of 9.7 :1.All the rest of the parts cylinderhead ,head gasket ,rods are all the same as the earlier D14 engines.One thing i also noticed is that the PHXG pistons are obviously stronger and thicker shaped.This could also mean they can handle much more power then the older P3Y pistons.
I Learned a lot from this ,i hope other people can use this info too
Picture time
