Does the jdm f20c come with the upgraded retainders in the ap2?
 

Have an Ap1 with a f20c replacement engine in it prior to when I bought it. As far as I know there jdm engines do not have a vin tag on them. Is there anyway to tell if these engines were produced after the retainer update was put in place?

Probably best to take the valve cover off and have a look.
Other than that the year when the engine was built could probably tell it as well.
https://www.s2ki.com/forums/s2000-un...ation-1189781/

In your case, yes, only way to find out is to take off the valve cover and check.

To my knowledge, all engines built 2004 and after do have upgraded retainers, this is true for F20C (EU,...) and F22C.

2004 F20C and after also come with the upgraded valve cover, if yours has the AP2 valve cover -> chances are your valve retainers are good too.

Wow that link is super helpful, I'll look into it when I get home. Also, it has the darker colored AP1 spark plug cover (I think it looks darker than the USDM engines cover) I did not know Japan got the golden spark plug cover the AP2 got. I'lll try to figure out from that link but either way my valve cover gasket has a minor leak anyway, might as well pull it and look

Oops, I just read you said valve cover and not spark cover. What is the main difference between the ap1 and ap2 valve cover I need to look for?

The PCV is 90 degree plastic pushed into a rubber grommet on ap1's and straight threaded metal on ap2's.