A simpler start stop technology

[190]

I'm not instinctively a fan of start stop due to the extra wear and tear on starter motors and the implications for battery size and number. It strikes me as stop gap clumsy engineering. Mazda have come up with an ingenious but simple way of way of engineering start stop that I have to admire. It doesn't use the starter motor and therefore has no impact on the battery. Basically the engine is stopped in a specified position such that injection of fuel and application of a spark will start the engine by combustion. It's said to be quieter and faster.

MAZDA: Idling Stop Technology | Environmental Technology

 

[MancMike]

Stops it after the suck and squeeze, starts it with the bang and blow.

Very clever. Although surely only one piston can be ready to rock (just past TDC) at any given time, so what happens if it misfires for whatever reason? I guess if that happens it’ll just use the starter motor to spin it around a bit to give the next cylinder past tdc a chance at glory.

 

[glenavy-drongo]

Had a girlfriend like that once....

D

 

[st13phil]

The Mercedes M157 & M152 use the same principle, but also use the starter motor to assist the in-engine direct start.

 

[E63S]

The simplest start stop technology is to press the button to disable it. I know it helps emissions and saves dolphins etc, but it’s without a doubt one of the most annoying feature on any car.

 

[Mactech]

It's an idea that has been around almost as long as direct injection petrol engines have been about.
We investigated this for racing engines very early this century, not to save fuel, but to save the weight of a battery and starter motor on Le Mans cars. It proved very difficult to position the pistons accurately each time, but I'm glad that almost 20 years later someone seems to have cracked it!

 

[m2287]

Mazda start stop is crap, I have it on my Mazda6 and it is so slow to activate I end up stalling the car
Nine times out of ten.

 

[Rory]

The Mercedes M157 & M152 use the same principle, but also use the starter motor to assist the in-engine direct start.

Don't some of them also use a belt driven combined starter / alternator? I remember having a B Class (I think) courtesy car and was very impressed by how seamlessly stop/start worked. My wife has a Tiguan with it and that's pretty rough - we always turn it off although I'll use it if it's obvious we're going to be stopped for more than a minute or so.

 

[kam09]

If you have MB diesel with start stop you could always get acid at Msl to gut the dpf and a remap after which will ensure the start stop stops working altogether as they don't know how to get the stop/start working seemlessly with a dpf removal n remap! ;p

 

[st13phil]

Don't some of them also use a belt driven combined starter / alternator?

Quite possibly, but the V8's don't.

The restart on the V8 is pretty instantaneous and quite seamless. I suppose that with 8 cylinders to choose from, the ECU has a greater chance of any one cylinder being in an optimum position to achieve a fuel/ignition start.

 

[st13phil]

We investigated this for racing engines very early this century, not to save fuel, but to save the weight of a battery and starter motor on Le Mans cars. It proved very difficult to position the pistons accurately each time, but I'm glad that almost 20 years later someone seems to have cracked it!

I always remember watching in slight disbelief the first time I saw someone start a veteran Rolls-Royce which pre-dated electric starters without hand cranking it. Trembler Coil ignition was the magic ingredient: the owner first hand cranked the engine to position a piston appropriately and then just move the advance/retard lever on the steering column at which point the engine burst into life!

 

[C7pg]

I’ve always wondered if some sort of (don’t laugh) clockwork device would work, by using engine rotation to apply tension (if you follow me) to a spring which would then be released when necessary? Would obviously need the starter motor to be available if it ran out of puff...go on shoot me down in flames.

 

[Ted]

There used to be wind up starters on equipment that didn’t need any electrics.
Not quite clockwork but similar (energy was stored in sprung plates)

 

[E55BOF]

I was told that the E350 diesel in my W212 had a hydraulic actuator to turn the engine over as part of the stop-start system.

Clockwork - well, spring wound up then released - starters are common on mopeds and small-capacity scooters.

 

[190]

I’ve always wondered if some sort of (don’t laugh) clockwork device would work, by using engine rotation to apply tension (if you follow me) to a spring which would then be released when necessary? Would obviously need the starter motor to be available if it ran out of puff...go on shoot me down in flames.

I'm quite sure there have been clockwork starter motors. I have a vague recollection of them being used on some 2 stroke scooters