ok i have a cuple questions..i have a h22a4 swapped in my 93 hatch, ok so about 3 month ago i got a knock and we figured out that its the piston were it it meets the wrist pin so i have to change that piston. a cuple days ago a friend of mine sold me a set of 4 pistons used from his old block and he told me they were from a jdm engine and that the copression was a tiny bit higher so i have to change all 4 of them...my question is, is he correct, is there a way to tell if the pistons are jdm or not what is the difference between the h22a4 i have and the base model jdm h22?(sorry dont know the egine code)....here are some pics if it helps..thnks

 

anyone?

 

the diffrence is on the side. the h22a4 ones that you have in the picture are hf3. the jdm h22a1 has hf1 on the side. make sure you know ur ring placement and gapping before you install they will work perfect for you. usdm h22a4 = 10.0:1 jdm h22a1 = 10.6:1 cr

 

thanks ur a good man