Specs and Compression calculators

D14A3 / D14A4 / D14Z1 / D14Z2

This page is mentioned for people who want to calculate the compression ratio of their engines when swapping out parts with other D-series engines. Since most available (if not all) compression calculators do not cover D14 engines, you’ll find the missing specs here. Also I present some links to compression calculators. Use them at your own risk, Errors may be present in the numbers on my website and on the websites of these calculators. One of the most common errors is that gasket thickness is not corrected for tensioning. Many thanks to hondaNickx for his very accurate measurements.

D14 rods:
-rod length, centre to centre 138 mm
-big end bore: 43 mm
-piston pin: 19 mm
-piston to deck height 0 mm

P3Y pistons found in D14A3/A4 (D14Z1/Z2 is different, piston is P3HG or alike):
-compression height: 29.5 mm
-dish shape: -5.4 cc

-bore 75 mm
-stroke 79 mm
-deck height 207 mm
[-half stroke 39.5 mm ]
[-rod length 138 mm ]
[-compression height 29.5 mm ]
[-piston to deck height + 0 mm ]
[-total 207 mm ]

Combustion chamber D14A3/A4
-volume 34.6 cc
-stock compression ratio 9.1


Looking at the rod dimensions, it occurs the rod used in our D14 engines is similar if not the same as the one used in D13B2 engines. For these engines, some aftermarket suppliers (Crower is the one I know of) do supply rods from stock. Bringing a bullet proof D14 a step closer.
Compressed thickness of a stock D14 head gasket is 0.028″ or 0.71 mm. It seems SolBlu corrected his values lately, but Zealautoworks needs correction for this. They still use uncompressed values.

Please, send any questions and/or remarks to me.

Dodo Bizar

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