Will stop/start save petrol?

[mointainwalker]

I work on a few Stop/Start Motorcycles and they all do it by using a modified Permanent Magnet Rotor and Stator assembly (basically running the charging system in reverse). Nothing to wear out and silent in operation.

I don't understand this, Keith . 30+ years ago permanent magnet alternators disappeared as a fuel-saving measure. Are you saying that permanent-magnets have been re-introduced as part of another fuel-saving measure (which they are going to nullify ) ? Obviously I don't have one of these, so may not be aware if there is any extra technology involved to make it work (fuel-saving that is ). I will be interested to know.

 

[Nige F]

That's similar (it would appear) to the old Magdyno system of yore.....I didn't realise that bikes had a stop/start system but I guess it's inevitable.
Our Post Office vans are Peugeots and Fiats just now - all on 67 plates - which have a conventional starter.
John

Dynastart ?

 

[Stivino]

Dynastart ?

Yep, like my 1973 Yamaha CS5 200E

 

[Burnerman]

That's the one....I believe Villiers had a similar method on their 200cc engine used in invalid carriages and other 3 wheelers.
John

 

[Keithmac]

I just removed a Dynastart from a 1980s RD200..

That system with mechanical charging regulator was just junk!.

Most motorcycles have permanet magnet rotors and stators already, just for charging though.

Brushed car alternators are a step backwards from a Permanent Magnet Rotor system coupled with a Mosfet regulator imho.

 

[Avocet]

I'm amazed they elected to use a conventional starter motor with stop/start cars, make cringe as well just thinking about it.

I work on a few Stop/Start Motorcycles and they all do it by using a modified Permanent Magnet Rotor and Stator assembly (basically running the charging system in reverse). Nothing to wear out and silent in operation.

I think some of the smaller PSA engines start again via the alternators. They can't do it on larger engines because of the load through the rubber in the crank damper on the bottom pulley. Even then, they still have a conventional starter motor for cold starts.

 

[Avocet]

typical car engine ticking over will use about half a litre per hour, so a 30 second stop will save about 0.6pence of fuel -

cost of new starter motor and fitting £450 ? so payback time wold be stop start engaged for 661 hours (thats about 28 days)

Maybe not that simple though. If manual transmission (and most likely fitted with a dual mass flywheel), the ring gear would only have to last the life of a clutch, perhaps. A new DMF would probably give you a new ring gear at the same time. I could see that being "a thing" where, when the clutch wears out, you get a recon starter, DMF and clutch "deal".

We do have both a climate and an air quality problem. We can't really just keep pretending we don't. Yes, the drive can always exercise common sense and either hit the "disable" button (if it has one) as he comes up to a set of lights that he knows are about to change, or keep his foot on the clutch. Every little helps!

 

[Nige F]

That's the one....I believe Villiers had a similar method on their 200cc engine : 3 wheelers.
John

They did - have a and google scootacar . One I had in the 70's

 

[Burnerman]

I'm thinking of the Bond Minicar....when the dynastart packed in, you lifted the bonnet, stuck your foot on the kickstart and (occasionally) away you went.
John

 

[norseman]

I'm thinking of the Bond Minicar....when the dynastart packed in, you lifted the bonnet, stuck your foot on the kickstart and (occasionally) away you went.
John

God that was a while ago John, a mate of mine had one when I was 16 & only had a push bike.
I seem to recall he always used the kick-start

 

[Astra99]

My Kia Niro Hybrid uses something akin to a dynastart. From what I can understand, it operates at 240V, drawing its power from the traction battery, which it then tops up when the engine is running.

 

[Burnerman]

God that was a while ago John, a mate of mine had one when I was 16 & only had a push bike.
I seem to recall he always used the kick-start

A mate had one when I was at school.....his party trick was to steer full left lock and set off. The car would spin on its length and centrifugal force would almost hurl the driver out of his door
John

 

[Burnerman]

My Kia Niro Hybrid uses something akin to a dynastart. From what I can understand, it operates at 240V, drawing its power from the traction battery, which it then tops up when the engine is running.

I know the 'mild hybrid' system uses the alternator to provide extra drive on occasion....how effective this is I really don't know but I expect we'll all have this at some point.
John