Just wondering what PR3 is? I had a PR3 cam gears on my 1st LS motor, that's what it said on the cam gear. I just bought a GSR off my friend and the cam gears say PR3, Is that right? Are all the b18 Cam Gears the same, will they all say PR3 on them. Sorry I am just really confused. I tried to look up on ebay all I get is 89-91 CRX stuff, and a Type R head. So what are PR3 cams? How can you tell the difference in cams?

 

https://honda-tech.com/zerothread?id=662681

 

Honda uses certain numbers to designate parts on a certain car. And when it comes to the B16A, all original parts are designated 'PR3'. There are a couple of things I should note, however. First of all, other engines may use certain parts in common with the original, 1G B16A in an effort to cut costs. This is why the B18 and B20 both use PR3 can gears. And this is why the ITR uses a PR3 head casting. Also, newer variants of the B16A have revised parts. These may carry other designations, such as P30. But on parts which remain unchanged on newer B16A variants (like the block and head), the PR3 designation remains.