Well after reading a lot of good stuff about the nippon pistons i decided to order a set for my rebuild on my type r motor. I ordered a set on ebay which said jdm itr p73 pistons. I recieved the pistons and they say p73-a0. I thought p73-a0 was usdm type r pistons with 10.6 compression and p73-00 was jdm itr pistons with 11.1 compression. So my questions is does nippon make a copy of the usdm and also the jdm ones or are they just labeled a0 but will still have 11.1 compression?

 

Im pretty sure the only way to get the JDM P73-00 pistons is through a dealer, or a supplier who imports them. I have never seen a "aftermarket" remake of them.

Can you supply a pic of the dome? Im pretty sure they would not stamp them 1 thing when they were another.

 

will post pics in a bit...but anyone else who can help?

 

http://cgi.ebay.com/ebaymotors/NIPPO...Q5fAccessories

 

Those are CTR pistons

 

i got these

http://cgi.ebay.com/ebaymotors/NIPPO...Q5fAccessories

 

p73-A0 (USDM B18C5)
p73-00 (JDM B18C5)
I know you can get OEM USDM and JDM pistons from RS machine. You can get them oversized to. Here is a good Honda compression calculator.
http://www.c-speedracing.com/howto/c...c/compcalc.php

 

I dont think you can get the JDM ITR slugs, just usdm. I looked all over for them in oversized sizes when building my motor.

 

The Nippon ones are USDM copies, not JDM. I looked at them when I was buying ITR pistons.... and 93eg is correct, it's impossible to find JDM ITR .25 OS pistons now.

 

yea my bad clicked the wrong one.

http://cgi.ebay.com/ebaymotors/NIPPO...Q5fAccessories

 

i asked the seller and this is what he told me:

These are copy of the higher compression pistons. The dome height is just like the JDM ones. The deck is stamped AO because the USD have deeper valve reliefs so they can be used with High Lift camshafts.

 

Only way to find out 100% is to have the piston dome cc'd

 

damn i dont wanna do all that!

anyone else ever have experience with the pistons?

 

I've used those ITR copies and the PR3 copies on several builds. All still running strong. Perfect machine work and assembly is key.

 

Deeper valve reliefs on the P73-A0's than on the P73-00's?
I call BS on that one.

 

no it's true the usdm has deeper valve reliefs but a lower dome than the jdm

 

Hmmm, Ive never heard that before. learn something new everyday! I wonder what the reasoning behind that is?