somebody help me with compression ratio math?
 

I was reading a Honda tech book and stumbled on something a bit confusing. First of all, it says the compression ratio in my D15B7 is the same as a D16Z6, both are 9.2. This isn't too unusual, I just thought VTEC may have a slightly higher ratio. Anyways, It also said that the cylinder head volumes are 38 on my D15B7 and 34.6 on the D16Z6. This volume is larger on my smaller 1.5 litre? Since their compression ratios are identical, this means that the volume of the cylinder at BDC is larger on my car than on the D16Z6. That doesn't make sense; how can the volume of the cylinder of a 1.6 litre be MORE than on a 1.5? Is the stroke difference pivotal?

For what it's worth, the Mini-Me swap mathematics works out to a 10.1:1 ratio, even though you guys say it will be higher.

Re:somebody help me with compression ratio math?
 

I said one of my last statemtns backwards. I meant, how can the volume of the cylinder of a 1.5 litre be MORE than on a 1.6?

Re:somebody help me with compression ratio math?
 

The cranks are different, the b7 has a shorter stroke.

The head cc's are different too, the Z6 head chamber is way less than the a6/b2/b7 head.

Jeff