noodels

Think JDM would be
JDM 00
US A0
rest of world A0<with a number of config><1-3>and maybe Australia another.
similar to ECU numbers
Given
P73-00 = JDM ITR piston, CR=11:1
• P73-A0 = US ITR piston, CR=10:6
from
http://www.ff-squad.com/tech/temp/pistons.htm

if rebuilding get after market pistons or maybe get some made

RWDlover

Sorry but you are wrong. The JDM is using the same gasket as the EU and US model, part nr. 12251-PCX-004. Never a manufacturer would alter the compression ratio from the gasket anyway because it alters the camshaft timing and affects the chain tension. The JDM has higher compression ratio resulting from the larger piston dome volume, hence the different part number for the JDM pistons.

RWDlover

And usually E or G for Eu.

Good luck using aftermarket pistons in FRM cylinders, even Mahle Golds don't last long at all.

Flipz

I read a lot on this a while ago and the head gasket thickness was the conclusion I came to as well but I forget what finally made that decision for me.

However, when I recently took the head gasket off my UK spec stock engine, I was surprised how thin it was compared to the Spoon (supposedly "extra" thin) gasket that will replace it.

RWDlover

One more time, it's not from the head gasket.. the head gasket is the same part number for all the F20s worldwide. And it is 0.6mm. Spoon's is 0.3mm and it's raising the compression and alters and cam timing at the same time. Sure the Spoon looks thicker even though it isn't, it's a brand new uncompressed gasket.

Ultra_Nexus

Haha, yeah it'd actually advance the timing on them!

chrisr111

I'm afraid you are wrong

The part number stamped on Daves piston (13010-PCX-A00) is not exclusive to the JDM engine--it was also use in early USDM engines.

The USDM engine was never available in the JDM high compression state.

The conclusion being that the -A00 pistons do not raise compression ratio; it's the head gasket

Chris.

Ultra_Nexus

I was confused by this so did some reading. As I thought, the pistons are fine, but there is questions over whether the Golds are Forged or Hypereutectic.

We all know S2000 pistons are forged OEM, hence why they sound like a bag of sh1t when they are cold.

People are complaining about the golds having a 'sacrificial' coating on the skirt that doesn't last long. My response to that is 'WTF is the piston skirt doing touching the FRM in the first place!!!!

Sounds to me like these pistons have been installed without checking the piston to wall clearance of a hot engine.

Honda have used both cast and forged pistons with FRM liners with no adverse affects. Mahle make good products so it is installtion errors that are causing the premature wearing

RWDlover

I'm afraid you are wrong

The part number stamped on Daves piston (13010-PCX-A00) is not exclusive to the JDM engine--it was also use in early USDM engines.

The USDM engine was never available in the JDM high compression state.

The conclusion being that the -A00 pistons do not raise compression ratio; it's the head gasket

Chris.
[/quote]


OP said that his pistons are stamped PCX-00, not A00.

Part numbers for JDM pistons :
00-02 13010-PCX-010 (A) , 13020-PCX-010 (B)
02-03 13010-PCX-020 (A) , 13020-PCX-020 (B)
04-06 13010-PCX-040 (A) , 13020-PCX-040 (B)

EUDM pistons :

00-02 13010-PCX-A01 (A) , 13020-PCX-A01 (B)
02-03 13010-PCX-A03 (A) , 13020-PCX-A03 (B)
04-09 13010-PCX-A04 (A) , 13020-PCX-A04 (B)

There is no difference in the head gasket, it's the pistons.

Daytona-Dave

I'm afraid you are wrong

The part number stamped on Daves piston (13010-PCX-A00) is not exclusive to the JDM engine--it was also use in early USDM engines.

The USDM engine was never available in the JDM high compression state.

The conclusion being that the -A00 pistons do not raise compression ratio; it's the head gasket

Chris.
[/quote]


OP said that his pistons are stamped PCX-00, not A00.

Part numbers for JDM pistons :
00-02 13010-PCX-010 (A) , 13020-PCX-010 (B)
02-03 13010-PCX-020 (A) , 13020-PCX-020 (B)
04-06 13010-PCX-040 (A) , 13020-PCX-040 (B)

EUDM pistons :

00-02 13010-PCX-A01 (A) , 13020-PCX-A01 (B)
02-03 13010-PCX-A03 (A) , 13020-PCX-A03 (B)
04-09 13010-PCX-A04 (A) , 13020-PCX-A04 (B)

There is no difference in the head gasket, it's the pistons.
[/quote]

Yep the pistons are PCX-00 and when cold have a fair old bit of piston slap going on perfect when warm hence the reason for a health check and look for info.

Almost everyone that drive's my car comments on how free revving it is and as we know the car is a JDM i wanted to find the things that give it that feel, from what i have read and posted here the pistons to me would be the most logical, some say HG but it's a big jump in compression to find in a gasket thickness but possible to gain some although if the part No is the same then it would seem unlikely but there does seem to be a lot of folk who support the head gasket theory

A couple of more questions has the JDM got a lighter fly wheel some say it has others say it's the same has anyone ever weighed one, plus they don't have an oil sensor on the vtec solenoid, can anyone shed any light on why and what this achieves,

thanks for all the replies