• In-Line 4-Cylinder
• Engine Block/Cylinder Head: Aluminum-Alloy
• Displacement (cc): 1668
• Horsepower @ rpm (SAE net): 100 @ 6100
• Torque (lb-ft @ rpm): 98 @ 4000
• Bore and Stroke (mm): 75 x 94.4
• Compression Ratio: 12.5:1
• 16-Valve SOHC VTEC®-E
• Multi-Point Natural-Gas Fuel Injection
• Front-Wheel Drive
• Emissions Rating: SULEV
• Direct Ignition System with Immobilizer
• 110,000-Mile Tune-Up Interval

Still looking for the head volume.

Source: http://www.mohawkhonda.com/new/civicgx.cfm