Those Dyno Guys - V-Twin Compression Calculator
    V-Twin Compression Calculator  
  Pick Engine Size        
          Use for custom configuration or oversize bore. Leave at 0.000 to use default values OR change any value to override default.  
  STD Bore Alternate Bore  
  Stroke Alternate Stroke  
  Rod Length Alt Rod Length  
  Head Gasket Thickness inches Stock=.045, Cometic MLS .030 or .040  
  Head Gasket Bore inches Stock 88, 96=3.850, 95, 98, 103 and 107=3.910  
  Cylinder Head Volume CC's Your measured volume should be entered here  
  Deck Height Front Cyl inches Negative number if piston  
  Deck Height Rear Cyl inches is ABOVE cylinder    
  Optional Piston Diameter inches Measure above top ring**  
        ** Leave Both at Zero OR enter BOTH values  
  Optional Top Ring Land inches Distance from piston crown to top ring**  
  Piston Dome Volume CC's Stock & Flat tops=-1.0 to -1.5 **  
      10.25:1 SE Cast 95=10.5 to 11.0 **  
      10.5:1 Forged 95=11.5 to 13.0 **  
  Static Compression :1     ** Total volume for 1  
          piston, not both  
  Engine Displacement ci      
  Dynamic Compression        
    Cam Offset Degrees **  
  OR     **Applies to both chosen or entered value  
  ** Enter Intake Close ABDC        
  ** (Set to ZERO if using a Selected Cam)        
            Conversion Calculator  
  Altitude Correction       From  
  Feet Above Sea Level     To  
  Corrected Compression :1    
  Cold Cranking Compression  
  Values in RED are approximate. Use actual measured values only. This calculator is supplied as a convenience and intended to be used for estimates only. We make no warranties, implied or expressed, to the accuracy of any data or calculations presented here.