^AnDre^

I am being told that there are 2 different types of Piston rings for an AP1, one for later model ap1 and one for earlier. I picked up some JDM +0.25mm rings and unfortunatly the mechanic threw out the boxes. Just looking to see if there is a difference between the 2 rings or not. Apparently one is ending with a part number 030 and the other 020.

VAD

The 030 and 020 refer to the size of the bearing relative to stock. .020" oversized or .030" oversized. The remainder of the part number should have been identical.

jyeung528

huh

^AnDre^

Apparently the last extension does not designate overbore size as the only one offered by honda is 0 and 0.25mm. Honda tells me that over the life of the AP1 they changed part numbers for the pistons and same for the piston rings, i do believe the only difference is that it is a different parts manufacturer. I just need to confirm that both rings are the same and are interchangable. I will get the part numbers in a bit and post them up here.

VAD

Generally, a suffix like -020 or -030 represents an oversized ring to fit a corresponding oversized piston for an engine that's been bored out. .25mm is roughly .010". (It's actually closer to .011", but that's how it's done. I don't make the rules, I just play by 'em.) The only OEM Riken piston rings I can find online are .25mm oversized. My guess would be that anything over .25mm (.010") is not recommended by Honda because of the cylinder wall material.

Andre, I'll be interested what you find out in regards to the ring part numbers.

VAD

OK, I looked on hondapartsunlimited.com and found the 2001 part number to be 13011-PCX-004 and the 2003 part number 13011-PCX-014. Both of these are standard sizes, not oversizes. It's definitely possible that it was as simple as a change in suppliers, as Andre suggested.

Tugz_S2K

The part number changed from a 004 to a 014....that indicates a major design revision. If dimensionally the same, then there probably is some material composition change with the rings. More then likely a countermeasure put in place to better control oil consumption.

90crvtec

According to this post the whole 020 and 030 seems pretty darn legit. I think this is the difference between '00-'01 and '02-'03 but I'm just speculating at this point. Based on what I'm seeing it would seem that the 020 and 030 is not related to the overbore size. But hey, what do I know.

VAD

90crvtec, good find. That would seem to explain it. Not necessarily indicative of a "major design revision", but there is a difference nonetheless.

^AnDre^

yes good find indeed. Now the question would be what would be the design revision.