allmotoronly
02-18-2008, 10:23 PM
Here's a list of different B series compression ratio's using oem honda pistons with different B series block/head combinations.
(All calculations use OEM Honda head gasket thickness.)
1) B16A Block with B16A/B, or B18C5 head
PR3 (USDM B16A) pistons: 10.20:1
PCT (JDM CTR) pistons: 10.80:1
P30 (JDM B16A) pistons: 10.40:1
2) B16A Block with B18C1 (P72) head
PR3 pistons: 10.44:1
P30 pistons: 10.65:1
PCT pistons: 11.07:1
P73-00 (JDM ITR) pistons: 10.42:1
P73-A0 (USDM ITR) Pistons: 9.94:1
P72-A0 (USDM GSR) pistons: 9.16:1
3) B18A/B Block with B16A/B, or B18C5 head
PR4 (B18A/B) pistons: 9.98:1
PR3 pistons: 11.32:1
P30 pistons: 11.54:1
PCT pistons: 11.97:1
P73-00 pistons: 11.31:1
P73-A0 pistons: 10.80:1
P72-A0 pistons: 9.99:1
4) B18A/B Block with B18C1 (P72) head
PR4 (B18A/B) pistons: 9.73:1
PR3 pistons: 11.59:1
P30 pistons: 11.81:1
PCT pistons: 12.27:1
P73-00 pistons: 11.57:1
P73-A0 pistons: 11.03:1
P72-A0 pistons: 10.18:1
5) B18C1/5 Block with B16A/B, or B18C5 head
PR3 pistons: 11.11:1
P30 pistons: 11.33:1
PCT pistons: 11.75:1
P73-00 pistons: 11.11:1
P73-A0 pistons: 10.60:1
P72-A0 pistons: 9.80:1
6) B18C1/5 Block with B18C1 (P72) head
PR3 pistons: 11.37:1
P30 pistons: 11.59:1
PCT pistons: 12.04:1
P73-00 pistons: 11.36:1
P73-A0 pistons: 10.84:1
P72-A0 pistons: 10.00:1
7) B20B/Z Block with B16A/B, or B18C5 head
P3F (B20B) pistons: 9.10:1
PHK (B20Z) pistons: 9.96:1
8) B20B/Z Block with B18C1 (P72) head
P3F (B20B) pistons: 9.24:1
PHK (B20Z) pistons: 10.14:1
If anyone needs any other B series combination thats not listed, pm me with the block, head, and piston type. I'll post different B17A specs if there is any interest. This stuff just takes a long time to figure up. I've been working on this for about 3 weeks in my spare time. I know this probably mostly applies to the N/A section, but I figured general tech would be the best place to put it so everyone could see.
Reps would be appreciated.
(All calculations use OEM Honda head gasket thickness.)
1) B16A Block with B16A/B, or B18C5 head
PR3 (USDM B16A) pistons: 10.20:1
PCT (JDM CTR) pistons: 10.80:1
P30 (JDM B16A) pistons: 10.40:1
2) B16A Block with B18C1 (P72) head
PR3 pistons: 10.44:1
P30 pistons: 10.65:1
PCT pistons: 11.07:1
P73-00 (JDM ITR) pistons: 10.42:1
P73-A0 (USDM ITR) Pistons: 9.94:1
P72-A0 (USDM GSR) pistons: 9.16:1
3) B18A/B Block with B16A/B, or B18C5 head
PR4 (B18A/B) pistons: 9.98:1
PR3 pistons: 11.32:1
P30 pistons: 11.54:1
PCT pistons: 11.97:1
P73-00 pistons: 11.31:1
P73-A0 pistons: 10.80:1
P72-A0 pistons: 9.99:1
4) B18A/B Block with B18C1 (P72) head
PR4 (B18A/B) pistons: 9.73:1
PR3 pistons: 11.59:1
P30 pistons: 11.81:1
PCT pistons: 12.27:1
P73-00 pistons: 11.57:1
P73-A0 pistons: 11.03:1
P72-A0 pistons: 10.18:1
5) B18C1/5 Block with B16A/B, or B18C5 head
PR3 pistons: 11.11:1
P30 pistons: 11.33:1
PCT pistons: 11.75:1
P73-00 pistons: 11.11:1
P73-A0 pistons: 10.60:1
P72-A0 pistons: 9.80:1
6) B18C1/5 Block with B18C1 (P72) head
PR3 pistons: 11.37:1
P30 pistons: 11.59:1
PCT pistons: 12.04:1
P73-00 pistons: 11.36:1
P73-A0 pistons: 10.84:1
P72-A0 pistons: 10.00:1
7) B20B/Z Block with B16A/B, or B18C5 head
P3F (B20B) pistons: 9.10:1
PHK (B20Z) pistons: 9.96:1
8) B20B/Z Block with B18C1 (P72) head
P3F (B20B) pistons: 9.24:1
PHK (B20Z) pistons: 10.14:1
If anyone needs any other B series combination thats not listed, pm me with the block, head, and piston type. I'll post different B17A specs if there is any interest. This stuff just takes a long time to figure up. I've been working on this for about 3 weeks in my spare time. I know this probably mostly applies to the N/A section, but I figured general tech would be the best place to put it so everyone could see.
Reps would be appreciated.