i have a usdm h22a4 that went on me(low compression), i ended up finding a jdm h22 odb2 short block for sale and bought it. the pistons at first looked domed like type s piston but after inspection they were P5M pistons but look different than my P5M h22a4 pistons. after searching for info on jdm P5M pistons cant find anything. anyone know what the compression would be with these pistons? are they 10.6:1 or 11:1? pics below of my usdm pistons and the jdm pistons

 

no one has any info on ODB2 H22 piston spec/compression ratio?

 

usdm are 10 to 1 jdm are 10.6 to 1

 

yep most jap pistons are a lil higher comp than their u.s. counterparts becuz of the higher octane fuel they use apexs numbers seem right

 

Only the JDM S Spec and Type S pistons are 11:1 regular JDM is 10.6:1

 

the p5m piston is the stock 10.1
all h22s are