If your car has points-based ignition, you'll find them in your distributor underneath the rotor. They're switch contact points or breaker points or whatever you want to call them, that are driven by a cam on the distributor shaft. They're closed most of the time, allowing current to pass through the primary side of the ignition coil. When they open, the ignition coil field collapses and you get spark out of the secondary side.
Unless your car is very old, chances are that you have a more reliable reluctor-based ignition, where instead of points you have a magnetic pickup that's triggered by a toothed wheel on the distributor shaft. That pickup drives an ignitor (which may also be inside the distributor, or it might be a separate module) which generates the high current input to the ignition coil primary.
You can twist the distributor to change your base timing, plus you have the vacuum mechanism that moves the points or magnetic pickup to adjust timing according to manifold vacuum, and it probably also has sprung weights that swing out as rpm increases, which moves the cam or reluctor wheel to advance timing.
The actual distribution part of the distributor consists of the rotor and terminals on the cap. That's what routes high voltage from the coil out to each spark plug.
On an old motorcycle, you just have the points (one set for each coil for each pair of cylinders as described above) without the distributor cap and rotor part. You can move the points around the cam to adjust base timing, and you might have springs and weights to advance timing as rpm increases. I don't think vacuum advance was nearly as common on bikes as it was on cars.
Hah, yeah. I like my shitty car projects. I'd like to replace my current daily driver, but I just can't get excited about new stuff, so it hasn't happened yet.
Unless your car is very old, chances are that you have a more reliable reluctor-based ignition, where instead of points you have a magnetic pickup that's triggered by a toothed wheel on the distributor shaft. That pickup drives an ignitor (which may also be inside the distributor, or it might be a separate module) which generates the high current input to the ignition coil primary.
You can twist the distributor to change your base timing, plus you have the vacuum mechanism that moves the points or magnetic pickup to adjust timing according to manifold vacuum, and it probably also has sprung weights that swing out as rpm increases, which moves the cam or reluctor wheel to advance timing.
The actual distribution part of the distributor consists of the rotor and terminals on the cap. That's what routes high voltage from the coil out to each spark plug.
On an old motorcycle, you just have the points (one set for each coil for each pair of cylinders as described above) without the distributor cap and rotor part. You can move the points around the cam to adjust base timing, and you might have springs and weights to advance timing as rpm increases. I don't think vacuum advance was nearly as common on bikes as it was on cars.