Do I need to modify anything to fit in the JDM Type S piston in my 5th gen? I've heard from few people that the JDM Type S piston wouldn't work for the USDM 5th gen, I never really know why. I thought since both engines are the same, just Type S have a higher compression than the USDM H22A, why wouldn't it fit?

 

The TypeS pistions just drop right in. No modifications are needed.

But you need to be sure you have the right sizes to fit your particular H22A block. There are regular and oversize TypeS pistons. Your block should have the piston size code on it (I'm not sure where exactly, maybe someone else knows...) It would look like "A A B A" - where A is a regular size, and B is the oversize to account for variations in block manufacturing. There are also .025 overbore Type S pistons. These are used if you have had your cylinder walls honed.

Andrew

 

good luck trying to find a B sized piston, i had to drive an hour and a half just to trade my A piston +$30bux with some guy who was selling his B

 

Since set A and B difference are only the size and since I want to do an oversize for my block, can I just used the biggest one I can find?

 

yea, just go with the oversize pistons and have your block bored out. thats probably the best way to go