ok these are both b16a motors, both 1gen, witch one is the jdm and witch is the usdm? i am confused on this i know one is the motor found in like ef8's and ef9's

 

Depends on which year of engine you are talking about. The USDM b16's (B16A3 - Del Sol VTEC & B16A2 Civic Si) all came with 10.2:1 compression (PR3 pistons), as well as b16a's sold in japan prior to 92. In 92 the intake manifold, cams, and pistons (P30) changed a little bumping compression to 10.4:1
Long story short, if you've got a USDM motor it is 10.2:1 with 160 hp, and if you've got a JDM motor (sold after 92 with the grey connectors) you have 10.4:1 compression and 170 hp.

 

ok so there is no jdm b16a with a compression ratio of 10:2:1?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1gen crxer &raquo;</TD></TR><TR><TD CLASS="quote">ok so there is no jdm b16a with a compression ratio of 10:2:1?</TD></TR></TABLE>

yes there is. The first generation JDM b16 has a compression ratio os 10:2:1.
which is jdm b16 -90-91.

 

so the jdm b16 with comp ratio of 10:2:1 is like 88-91 jdm b16? corrct me if im wrong

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1gen crxer &raquo;</TD></TR><TR><TD CLASS="quote">so the jdm b16 with comp ratio of 10:2:1 is like 88-91 jdm b16? corrct me if im wrong</TD></TR></TABLE>

That is correct.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline130 &raquo;</TD></TR><TR><TD CLASS="quote">

That is correct. </TD></TR></TABLE>
sorta, except the B16A started in 89, not 88.

 

1st-gen JDM B16A ('89-91) - 10.2:1

2nd-gen JDM B16A ('92-00) - 10.4:1

USDM B16A3 ('94-95) / B16A2 ('96-00) - 10.2:1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -KangaRod- &raquo;</TD></TR><TR><TD CLASS="quote">
sorta, except the B16A started in 89, not 88.</TD></TR></TABLE>

Ahh, missed that....just got back from the eye doctor, my eyes are still dialated...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Targa250R &raquo;</TD></TR><TR><TD CLASS="quote">1st-gen JDM B16A ('89-91) - 10.2:1

2nd-gen JDM B16A ('92-00) - 10.4:1

USDM B16A3 ('94-95) / B16A2 ('96-00) - 10.2:1</TD></TR></TABLE>