Head CC’s +
Cylin­der Dis­place­ment +
Deck Height Dis­place­ment
Com­pres­sion Ratio = _________________________________
Deck Height Dis­place­ment + Head CC’s
If your Bore is 90.5mm, Stroke = 82mm, deck height = 1.5mm, HeadCC’s = 46CC

Then your Cylin­der Dis­place­ment =
90.5×90.5x82x.0031416
___________________ = 527.47
4
Deck Height Dis­place­ment =
90.5×90.5×1.5x.0031416
____________________ = 9.65
4
There­fore:
527.47cc + 9.65cc + 46cc
_________________________ = 9.48:1
9.65cc + 46cc
To Find Head CC Needed For Any Com­pres­sion Ratio:
Cyl. Disp. + Deck HT. Disp. — (“Desired Com­pres­sion Ratio?” x Deck Height Dis­place­ment)
____________________________________
(“Desired Com­pres­sion Ratio”-1)

If your Bore is 90.5mm, Stroke = 82mm, deck height = 1.5mm, HeadCC’s = 46CC

Then your Cylin­der Dis­place­ment =
90.5×90.5x82x.0031416
___________________ = 527.47
4
Deck Height Dis­place­ment =
90.5×90.5×1.5x.0031416
____________________ = 9.65
4
Exam­ple: Cylin­der Dis­place­ment = 527.47cc
Deck Height = 9.65cc
Desired Com­pres­sion Ratio = 9.5 to 1
There­fore:
527.47 + 9.65 — (9.5 x 9.65)
___________________________ = 42.03
(9.5 — 1)
Deck Height Dis­place­ment Equals:
Bore x Bore x Deck Height in mm x .0031416
___________________________________________
4
There­fore:
92 x 92 = 8464 x 1.75 = 14812 x .0031416 = 46.5333
Divided by 4 = 11.93cc Deck Height
Exam­ple: Bore = 92 mm Deck Height = 1.75mm,
or 13/4 Turns On Our Deck Height Tool
Cylin­der Dis­place­ment Equals:
Bore x Bore x Stroke x .0031416
_______________________________
4
There­fore: 92 x 92 x 69 x .0031416
Divided by 4 = 458.7cc

Exam­ple: Bore = 92mm Stroke = 69mm

Posted by autoviceblogger on April 13, 2015