Engine Compression Ratio Calculation
How to calculate Compression Ratio
Forumla –
Example – 443.75cc
9.80cc
_____50.00cc
503.55cc
Compression Ratio Chart
1300, 1500, 1600cc Type I, II & III Single & Dual Port Heads CC in Head – Depth of Flycut
Bore X Stroke | 37cc .140 | 39cc .120 | 41cc .100 | 43cc .080 | 46cc .050 | 51cc varies | Engine Size |
85.5 x 69 | 9.68 | 9.31 | 8.98 | 8.67 | 8.25 | 7.64 | 1584 |
85.5 x 74 | 10.32 | 9.92 | 9.56 | 9.23 | 8.78 | 8.13 | 1699 |
85.5 x 78 | 10.82 | 10.41 | 10.03 | 9.68 | 9.20 | 8.51 | 1791 |
85.5 x 82 | 11.32 | 10.86 | 10.49 | 10.12 | 9.62 | 8.90 | 1883 |
87 x 69 | 9.91 | 9.54 | 9.20 | 8.88 | 8.45 | 7.83 | 1640 |
87 x 74 | 10.56 | 10.16 | 9.80 | 9.46 | 9.00 | 8.33 | 1760 |
87 x 78 | 11.08 | 10.66 | 10.28 | 9.92 | 9.43 | 8.73 | 1855 |
87 x 82 | 11.60 | 11.16 | 10.76 | 10.38 | 9.87 | 9.13 | 1950 |
92 x 69 | 10.76 | 10.36 | 10.00 | 9.66 | 9.19 | 8.52 | 1835 |
92 x 74 | 11.46 | 11.04 | 10.64 | 10.28 | 9.78 | 9.06 | 1968 |
92 x 78 | 12.02 | 11.57 | 11.15 | 10.77 | 10.25 | 9.49 | 2074 |
92 x 82 | 12.59 | 12.12 | 11.68 | 11.28 | 10.73 | 9.93 | 2180 |
