J
Jack Klarich
Guest
Dwell" is the number of degrees of distribtor cam rotation between lobes during which the points are closed and coil primary current flows. The definition also applies to electronic ignition systems, but rarely is the dwell in those adjustable- although with some, the dwell increases and decreases as engine speed increases and decreases. The reality of dwell is that it is a convenient way to measure, and adjust, the 'On' time for coil current. Dwell angle is also referred to as 'dwell angle', 'cam angle', and 'cam dwell.'
The importance of proper dwell adjustment is that the coil requires a certain length of time for the primary winding to reach its full, or at least useable, magnetic field strength (magnetic saturation) to provide reliable spark. Since the dwell angle adjustment affects the dwell time period (coil current interval), it is a fairly important setting. The actual dwell angle setting is a compromise that gives adequate coil magnetic field strength at high engine speeds, a short enough period to provide acceptable point life at low engine speeds, and enough point gap to prevent flash-over as they open. The condensor supresses point arcing upon opening, but the gap must prevent flash-over when fully open.
Maybe this is more than you wanted know, but there is more that can be said about dwell, coil saturation, point gap, dual points, condensor function, the effect on ignition timing, etc. Remember to check your timing after installing new points, and your advance unit for proper movement, a bit of lube on the cam lobe and you are good to go:s
The importance of proper dwell adjustment is that the coil requires a certain length of time for the primary winding to reach its full, or at least useable, magnetic field strength (magnetic saturation) to provide reliable spark. Since the dwell angle adjustment affects the dwell time period (coil current interval), it is a fairly important setting. The actual dwell angle setting is a compromise that gives adequate coil magnetic field strength at high engine speeds, a short enough period to provide acceptable point life at low engine speeds, and enough point gap to prevent flash-over as they open. The condensor supresses point arcing upon opening, but the gap must prevent flash-over when fully open.
Maybe this is more than you wanted know, but there is more that can be said about dwell, coil saturation, point gap, dual points, condensor function, the effect on ignition timing, etc. Remember to check your timing after installing new points, and your advance unit for proper movement, a bit of lube on the cam lobe and you are good to go:s