ok i have a cuple questions..i have a h22a4 swapped in my car(civic if wondering what car) 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

 

Those pistons look horrid. Lke they came out of an exploded motor. If your going to be putting new pistons into a block, you should have it resleved.

 

the pistons in the pics are the one that i bought of my friend, and no the block wasnt exploded or anything, he was just getting higher copression pistons for his block so he sold me those...

 

Those pistons do look horrid. Like the oil was never changed. And look at the ridiculous heat mark at the bottom. Do it right, or you'll be opening it up again soon.

 

i know that the piston in the pictures are from a 93-96 h22a1 . . .not sure if there is any difference between the pistons in the a1 and a4 . . . but the code P13 on the piston is printed everywhere on the h22a1 engine

 

I think the wrist pins are different from the a1 to a4, I think the a4 are a floating pin, and the a1 is a press fit.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thao0094 &raquo;</TD></TR><TR><TD CLASS="quote">i know that the piston in the pictures are from a 93-96 h22a1 . . .not sure if there is any difference between the pistons in the a1 and a4 . . . but the code P13 on the piston is printed everywhere on the h22a1 engine</TD></TR></TABLE>

JDM H22A has p13 stamped everywhere also

 

hmmm confusing....he did give me some new wrist pins but i though they didnt belong to the pistons because they would just slide right in and i thought they were supposed to be a press fit....am confused anymore help?...thanks everyone

 

take them to a machine shop and let them measure the pin bore with a bore gauge. They will be able to determine if they meet honda spec and if the pin housing is out of round.

looks like they saw some crazy heat tho and a good bit of blowby.

 

if you had a knock did the walls get damaged at all? If I were you I would get the block honed and put stock or aftermarktet set in, ones that work with a FMR engine. Otherwise your going to be doing this again or you might have to replace the motor which is more likely.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rob97’SH &raquo;</TD></TR><TR><TD CLASS="quote">if you had a knock did the walls get damaged at all? If I were you I would get the block honed and put stock or aftermarktet set in, ones that work with a FMR engine. Otherwise your going to be doing this again or you might have to replace the motor which is more likely.</TD></TR></TABLE>

it wasnt a knock that destroyed the motor or anything, i drive this car everyday 45 miles a day and iv had the noise for about 3 months now, the knock is commin from the piston were the wrist pin is at, the piston must be wasted there

 

those are NOT USDM h22a4 pistons. I can tell you that much, cuz I have a H22a4 and the pistons don't have the raised center like those do. The H22a4 pistons are flat topped with valve reliefs cut into them. Nothing too fancy. I know some of the JDM pistons were shaped more like what you have there, so that might be what you have.

 

Those look like pressed pin JDM pistons. They are what your friend says, but the problem you'll have is with the wrist pin. Early H22's used pressed pin and later ones use floating pin.

USDM H22A4 floating pin:



JDM H22A Type S (note raised dome) floating pin:



F23 floating pin, note the bushing in the rod, the ring clip, and the groove in the piston where the clip goes (the pressed pin pistons don't have this):