This calculator is intended for use as an estimate of your compression only. Not all values are verified and may have varied results base on casting flaws, ect... You should measure your exact engine for a true result. Use at your own risk, we take no responsibility for incorrectly entered values. Double check your numbers and ours. Make sure you always choose the same Series motor e.g. all D Series. Block Crank   B Series B16A - B17A D Series D16-17 B18A/B D15 B18C - B16B B20B/Z Other B Series B16A/B D Series D16 B17A D15 B18A/B - B20B/Z D17 B18C Other Bore (mm) Stroke (mm) Deck Height (mm) Head B Series B16A/B - B17A - B18C5 D Series D15B7 - D16A6 B18C1 D16Z6/Y7 - D15B B18A/B - B20B/Z D16Y8 ZC D17A2 D15Z1 Other Combustion Chamber Volume (cc) Piston B Series PR3 (USDM B16A) D Series PM3 (US D15B7) P30 (JDM B16A) P07-010 (US D15Z1) P61 (B17A) PM6 (US D16A6) PR4 (B18A/B) P2E-000 (US D16Y7) P72-A0 (USDM B18C1) P28-A01 (US D16Z6) P72-00 (JDM B18C1) P2M-00 (US D16Y5) P73-A0 (USDM B18C5) P2P (US D16Y8) P73-00 (JDM B18C5) PDN-A00 (US 98-00 GX) P3F (B20B) P29 / PM7 (ZC) PHK (B20Z) PMS-A00 (US 01-03 GX) PCT (JDM B16B) PG6 (US 86-87 D16A1) PLR-A0 (US D17A2) P08-010 (JDM 91-99 VTi) Vitara Other Dome (cc) Comp Height (mm) Connecting Rod B Series B16A D Series D16 - D17 - D15Z1/B B17A D15B1/B2/B8/B7 B18A/B - B20B/Z B18C1/C5 B16B Other Rod Length (mm) Headgasket Thickness .027" .036" .045" .030" .040" .051" Other Thickness (in) Bore diff (mm) * Head Milling and Block Decking Enter total amount head has been milled and block decked. (in) Maximum Operating RPM Enter max operating RPM to determine mean piston speed and max piston acceleration. (rpm) Elevation Enter operating elevation of engine to determine effective compression ratio. (feet) Boost Enter boost pressure to determine effective compression ratio. (set to 0 for NA setups) (psi) Static Comp Ratio : 1 Effective Comp Ratio w/Boost* : 1 Displacement cc Calculate Rod / Stroke Ratio : 1 Piston-to-Deck Height in Mean Piston Speed fps Max Piston Acceleration fps2