Calculate the dynamic compression ratio considering cam timing and intake valve closure. This provides a more accurate representation of actual compression in your engine.
Dynamic compression ratio accounts for when the intake valve closes during the compression stroke. This provides a more accurate representation of actual compression in your engine compared to static compression ratio.
Dynamic compression ratio is typically 1-3 points lower than static compression ratio. This is because the intake valve closes after bottom dead center, reducing the effective compression stroke.
Later intake valve closure (higher ABDC) reduces dynamic compression. This is often used in high-performance engines to allow more air/fuel mixture into the cylinder.
Dynamic compression ratio is a better indicator of fuel requirements than static compression ratio. Higher dynamic compression requires higher octane fuel to prevent detonation.
Choose cam timing based on your desired dynamic compression ratio. More aggressive cams often require lower static compression to maintain safe dynamic ratios.
Balance static and dynamic compression ratios. High static compression with aggressive cams can result in manageable dynamic compression.
Dynamic compression affects heat generation. Monitor cylinder temperatures and consider thermal management for high dynamic compression engines.
Always verify your calculations with actual engine testing. Use a compression tester to confirm your dynamic compression ratio estimates.