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 Flywheel 1
This is how it was traditionally taught: the flywheel should help overcome idle cycles and dead points. If the number of three-cylinder and possibly even two-cylinder engines increases before the electric revolution, then the
former could once again become part of the tasks of a flywheel or its replacement. For a long time, it seemed as if there would be no more idle cycles in combustion engines because they had at least four cylinders.
The flywheel was therefore a thick disc with as much mass as possible as far away from the center as possible. It was screwed onto the crankshaft so that it could not turn. Ideally, it would have been balanced together
with this, but that was difficult if only the flywheel was to be replaced due to damage caused by the clutch disc. So each part is balanced individually. Unlike with a wheel, where you add a weight if necessary, with these two,
material is drilled away on the opposite side.
In the past, you could even imagine learning a little about the characteristics of the flywheel on the engine while driving. Back then, engines were still weak, and
vans and cars often had the same power output and, more importantly, the same torque. Nevertheless, it could happen that the van could maintain its undoubtedly lower speed on the hill for longer than the car.
This was simply because it had been fitted with a flywheel with greater mass. This acts like a kinetic energy storage device. It is not without reason that experiments have been conducted with so-called clutches using
momentum, which allow a larger mass to continue rotating while waiting at traffic lights, thereby providing significant assistance to the engine when subsequently starting off.
Of course, such a flywheel also had a downside. The engine accelerated poorly, which always gave tuning enthusiasts the idea of making the flywheel even lighter. And then there's the pinion gear for the starter motor,
which has shrunk on. Why here? Because this is where the largest diameter is available, which facilitates the realization of a transmission ratio of well over 10.
Meanwhile, this form-fitting connection seems to be increasingly replaced by a force-fitting belt connection at the other end of the motor. The mild hybrid enters the stage. However, both solutions are initially still available on
one engine. Presumably, the generator converted to an electric motor, together with its belt drive, is not yet capable of starting the engine, e.g., in very cold weather.
This brings us to the secondary tasks. A second one began quite harmlessly at first. Due to the large diameter, markings were often added to adjust the ignition, as this was the most accurate method. However, some of
them were very difficult to access, which is why we ended up switching back to the V-belt pulley. After all, the best possible setting was the one with a strobe lamp.
By the way, whether the grooves are at the front or rear of the engine, it makes sense to check them if you have any suspicions or have carried out extensive tuning. So dial gauge, possibly with extension through the spark
plug hole, and TDC determined exactly. All other values can be calculated using the formula for radians, which is not too difficult.
For a long time, it remained mechanical, but then it became electronic, who would have guessed? First, a thickening appeared at the spot where the line described above had been. Together with a winding
whose iron core was temporarily extended by the thickening, this resulted in a signal that changed significantly at this point, and thus the OT sensor.
Some 'professionals' still call him that today, even though it doesn't adequately describe his work. At some point, the teeth were sufficient for the starter motor to generate a signal that could be clearly identified by the
engine control unit. From then on, it could count teeth, even at 6,000 or more revolutions.
Unfortunately, however, one signal was like another, so there was no prominent point. The motor technicians put a stop to the electronics engineers' tendency to leave out a tooth by pointing out that the starter motor would
probably not always have worked properly with this solution. And so the additional sheet metal ring was created, although it was photographed so poorly at the bottom of the picture that the double gap is obscured.
That is then the absolutely necessary reference point. That doesn't have to be TDC, because from there the engine control unit can determine all kinds of points itself. It can also scale more finely than the resolution visible
here might suggest. This is called interpolation, calculating finer divisions. For example, one could place five strokes between two of the existing ones in such a way that exactly after five, the sixth stroke fits perfectly through
the sensor.
What else is it needed for besides setting the ignition or fuel injection? Well, then please think about the four strokes, only one of which is productive. Among other things, the enormous increase in torque must have an
effect on this. This means that the control unit is now able to assign the acceleration to each cylinder in the working cycle.
In the past, to check that all cylinders were working properly, individual ignition cables were pulled on gasoline engines. The control unit now does this throughout the entire engine running time, thereby also regulating the
fuel supply and, if necessary, individual ignitions. And if the tolerances are still exceeded despite multiple adjustments, it switches off the cylinder for its protection, including a message and entry in the error memory. One
example, and all made possible by a metal ring.
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