Other than the pistons, which are higher comp. in the JDM engine, is everything else identical between the 2 engines?

I'm primarily interested in the valves, valve clearances, and the cams in the USDM engine vs. the JDM engine.

As always, any info is greatly appreciated! Thanks in advance!!

 

If I am not mistaken I think just the head gasket is different... JDM gets another 0.7 points of compression from that... not the pistons.

The head is identical.

 

Hmmm...I've actually heard the exact opposite -- that the additional 0.7 points of compression comes from the pistons and not simply with the gasket.

 

Well in that case this thread will enlighten me!

 

Completely OT, but I'm wondering why someone gave this thread 1 star. I found it informative and worth the click.

 

I still want to know as well....

 

Oh well, to each his own I guess...

Anyways, another point is whether or not the USDM ECU and JDM ECU are identical? Or does the JDM ECU factor in the increased compression?

 

not sure on wether the ECU's are the same or not, but the ECU cannot change compression.

 

I believe it's just a gasket change, but I could be mistaken.

 

I understand that the ECU cannot change compression, but I'm wondering if the JDM ECU adjusts for the higher compression of the JDM engine? For example, gives more fuel to ensure the JDM engine doesn't run too lean?

I've confimed that the 0.7 increase in compression in the JDM engines is not caused by the gasket, but the pistons. The JDM pistons are higher compression than the USDM pistons.