Chapter 6. Induction Fundamentals.|
12209 words. 36 illustrations.
Flow Issues. Flow alone is not the governing factor. Reasons why flow takes place. Pressure difference and velocity. Pressure changes through the induction cycle. Potential errors of simple flow measurement.
Port and Valve Sizes. Critical dimensions. Port geometry.
Flow Entry into Passages. Merits of various intake shapes. Vena contracta.
Aerodynamics and Ports. Viscous flow over a wing. Boundary layer. Coanda effect. Downwash. Flow though curved passages. Cascade of vanes. Turbulators. Multi-angle valve seat.
Unsteady Flow Dynamics. Pulses in pipes. Pulse reflection processes at open and closed pipe ends. Pressure changes at the valve throat in a resonant system.
Variable Geometry Systems. Changing tract length. Use of flap valves. Variable coupling of chambers and tracts.
Fuel Stand-off. Stand-off collectors.
Balance Pipes. Carburetor applications. Benefits and drawbacks in resonant systems.
Recovering Outgoing Pulses. Plenum chambers and air boxes.
Noise. Effects of restricted intakes.
Sonic Restrictors. Pressure ratio for sonic flow. The sonic venturi. LMP racing applications.
More Noise Issues. Quarter wave and Helmholtz resonators.
Detuning for Drivability. Plate over a bellmouth. Cosworth Sierra manifold.
A Classic Induction System - The Jaguar V12. Graduated flow through the system from intake to port.
Pumping Losses. How the deep suction phase is rewarded by greater mass flow.
Air Filtration. Losses and benefits with different types of filter.