Opel C20XE
The C20XE — the 'Red Top' — is Opel's 2.0-litre 16-valve four, square at 86 × 86 mm and running 10.5:1 compression in the preset. It became the default European club-racing and kit-car engine because it makes genuinely good naturally-aspirated power with a straightforward four-valve head, and because so much of its behaviour is limited by breathing rather than by the bottom end. That makes it a rewarding engine to model: changes to valve timing and port area move the result in ways you can feel on track. The calculator returns the thermodynamic cycle, P-V diagram, indicated and effective power and the crank-train loads.
Preset parameters
Values below are the preset the calculator loads — you can change every one of them in the form. Angles are absolute crank angle (CA) on a 0–720° cycle.
Reference figures
Manufacturer figures carried by the preset for comparison. They are reference values, not calculator output.
Notes for modelling
- Compare it directly with the C20LET preset — same block geometry, lower compression, forced induction.
- Individual-throttle-body builds are essentially an intake-pressure and valve-timing question; both are editable here.
- The preset is per cylinder; multiply effective power by four.