Pistons

[VTECnique]

Im just wanting to know something. Pistons out of a JDM ZC (PM7) and USDM D16A1 (P29) are the same, dont know about exactly the same, but they have the same compression height and dome. Im asking if the pistons out of an AUDM D16A8 have the same measurements as the pistons mentioned. Any help would be great!

[crx_boy7]

yes yes iv rebuilt a zc with d16a pistons . they are absolutely identical
but my D16a8 is aus spec id guess the us pistons would be the same if its the same non vtec dohc.

[VTECnique]

Oh sweeet az, Im building a hi comp d16y4. So ZC and D16A8 pistons are identical!?!? I just know that AUDM A8 pistons are going to be cheaper than JDM ZC pistons...

[sivic]

yes yes iv rebuilt a zc with d16a pistons . they are absolutely identical
but my D16a8 is aus spec id guess the us pistons would be the same if its the same non vtec dohc.
so did you rebuild a actual ZC or a D16A8?
i know they are essentially the same engine (i had a D16A8, now i have a JDM ZC)
but there are minor diffs.
i saw a comparison between the 2 pistons and while not noticable at a glance there were diffs. the JDM ZC apparently has a CR of 9.6:1 compared to the D16A8 which has 9.5:1.

[VT3C]

a 0.1 increase in compression through use of ZC pistons in your D-series aint gonna do sheet.. Why bother ? and if u consider the cost of new HONDA pistons, IMO you are MUCH better off to go aftermarket pistons such as JE etc would be a much better option and probably favourable in price. You're paying for the hard part (labour) so IMO MUCH MUCH better to get true high-comp pistons rather than that 0.1 increase in compression..whoa Butt-Dyno(tm) watchout !!

[VTECnique]

Sorry, i forgot to explain that these pistons will be fitted to a sohc d16y4, and will be buying them 2nd-hand!

[VT3C]

still not worth the effort IMO - u might as well just put new rings on your old pistons.

even if you had those ZC pistons for FREE I still think you'll spend all this $$$ on the labour to install new pistons (essentially a full rebuild) and then you'll have a power gain that is practically un-noticable.

If u want a power gain that may be more noticable - like I said before get the aftermarket pistons for just a little more.. plus they will be much stronger than cast OEM pistons.

[VTEChnique]

VT3C is correct :)

- KB

[VTECnique]

Yeah fair enough, but I will be fitting the pistons myself. I'm fitting dohc d16 pistons in a sohc d16!! A8/ZC pistons are domed, where as sohc d16s are dished, so my c/r will be at 12 - 12.5:1. I know forgies are much stronger than cast, but im only building a hi comp setup for street use, plus im on a tight budget. If u cant help me with the question i asked in the first place then dont bother posting...