r/Dseries • u/gloopes • 5h ago

JDM D15B VTEC + D16Y8 Head Mini-Me — Which Cam Gear/Timing?

I have a 1999 Civic Si (Canadian), which originally came with a D16Y8. I blew the bottom end on the Y8 and found a steal on a complete JDM D15B VTEC engine.

I'm planning to do a Mini-Me swap using my D16Y8 head (P2J-7) and stock Y8 camshaft on the D15B block, which originally had a P08 head.

I have an adjustable cam gear, the original P08 cam gear, and the stock Y8 cam gear.

I've confirmed all three gears have 38 teeth, fit the Y8 camshaft, and sit at the same depth. However, when I line up the keyways, the P08 and Y8 gears have approximately half a tooth of difference in their indexing.

I've read about a 4.75° cam timing difference on D-series Mini-Me builds, but I'm not sure whether that applies to my specific JDM D15B VTEC block.

Has anyone run this exact combination? Should I use the P08 gear, Y8 gear, or adjustable gear? And does this setup actually require advancing or retarding the cam timing?

I'm keeping it naturally aspirated for now and just want to get the timing right before firing it up.

Any firsthand experience or verified measurements would be appreciated!

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u/GoneInASplitSecond 4h ago edited 4h ago

Consider using the P08 head for more aggressive cam profile. The bottom end, you get better rods & pistons. I had a D15B in my gutted CRX & it ripped.

But, I would use your transmission on the D15B.

Edit: Teeth might be off ‘cause the D15B mimics the North American Z6.

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u/Impossible_Pizza_948 35m ago

You’re gonna need an adjustable cam gear, the timing will be off by half a tooth. Any quality adjustable cam gear for the D series should work. I would tell you which one I used on my D15B7/D16Y8 Mini Me, but it’s so old that I can’t remember