Dave Plowman (News) wrote:
In article ,
Roger wrote:
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Wonder what they will invent next - synchromesh? Four wheel brakes?

Geoff MacK

The next version of this system is in development, and it could be on
this car, is starting the engine without the starter motor. The ECU
does a controlled stop when the engine is switched off so it stops in a
certain position, then to start an injector fires and the plug sparks
and this starts the engine. This only works on a hot engine. This,
direct injection, turbo charging and loads of EGR will be standard on
all petrol engines in 10 years time.

Nothing new there. I am sure I remember an dealer demonstrating how he
could start a 1934 Bentley by triggering the magneto ignition.

Think a magneto can only produce a spark when the engine is turning. Coil
ignition will produce a spark if the coil is energised and the points
opened - done by moving the distributor via an advance/retard lever.

You are right. A magneto is effectively a high output dynamo, so it
needs to be turning to produce any output. By contrast, a coil produces
a spark when the circuit to it is broken (the spark occurs when the
points open)

The early Rolls Royces had both coil and magneto for reliability. But it
was the coil circuit that allowed the engine to be started by using the
advance/retard control.

I watched one being started like that at a car show. Impressive, but
eerie to watch. But the trick worked because there were lots of
cylinders, so one was always in the right position to fire, regardless
of where the engine stopped. I can't imagine any ECU controlling a
4-cylinder engine to stop it immediately after TDC with the contents of
the cylinder under compression, nor any residual petrol/air mixture
having enough power when fired to turn such an engine from stationary
through 180 degrees against the compression of the next cylinder to
fire. Are Fords going to start making V12s?

Jim