Can direct injection engines start without a starter motor?

jim beam wrote:
>
> On 09/10/2011 08:34 AM, jim wrote:
> >
> >
> > jim beam wrote:
> >>
> >> On 09/09/2011 08:04 PM, hachiroku wrote:
> >> <snip for clarity>
> >>
> >>> I'd be wondering, however, if
> >>> it might get the crank going in the wrong direction, hence the need for a
> >>> motor to ensure proper rotation.
> >>
> >> good point. this is likely because as an engine stops rotating on
> >> shutdown, it "bumps" up against compressed mixture on whatever piston is
> >> in the compression stroke, and stops /before/ tdc, not after. even if
> >> the mixture could be ignited cold, the piston would have to be
> >> positioned after tdc, not before.
> >
> >
> > Actually that is not necessarily the case.
> >
> > The one engine i have seen that would self start looked like it would run
> > backwards for something 90-140 degrees and then reverse and run forward.
>
> then you had a serious carburetor problem dumping vast excess gas.

No, The only thing unusual about the engine was that it had very low
resistance. When warm you could push on the fan with one finger and get
the engine to turn.

As for extra gas. There is always excess gas pumped into the exhaust when
you shut off the engine.


> the
> only way a gasoline engine can "run backwards" is if it's getting fuel
> from the exhaust.

Of course there is gas in the exhaust. What did you think happened when
you turn the engine off? There are a few engines designed with a solenoid
in the carb that cut off the flow when ignition is turned off, but most
engines just keep sucking gas until the engine stops turning.

> if you're dumping unmetered gas so it's accumulating
> in the exhaust, it might run as long as that fuel vapor can exist in the
> pipe, but beyond that, it's game over.

It didn't run backwards. It started by turning backwards about a 1/4-1/2
revolution and then reversing and running forward. Sometimes it would not
reverse, but run for one or two revolutions backwards and sometimes when
you turned the key back to on it would do like most engines (which is
nothing).

>
> >
> > If you turned the warmed-up engine off and waited about 2 seconds and
> > turned it on it would sometimes start right up. Sometimes it would kick
> > back and blow smoke out the air intake and sometimes it would kick-back
> > and then reverse and start running. And sometimes it would just do
> > nothing when you turned the key back to on.
> >
> > This was an IH engine with carburetor and points.
> >
> > -jim
>
> historically, many [diesels - see above] engines have been able to "run
> backwards".

I didn't say the engine "ran backwards" at least not for any amount of
time. The engine revolved in the reverse direction for less than 1/2 turn
and then changed direction and started up and ran normally. This was on a
step-van so with the engine cover off you were sitting right next to the
engine and you could watch the fan turn.

On 09/10/2011 09:37 AM, jim wrote:
>
>
> jim beam wrote:
>>
>> On 09/10/2011 08:34 AM, jim wrote:
>>>
>>>
>>> jim beam wrote:
>>>>
>>>> On 09/09/2011 08:04 PM, hachiroku wrote:
>>>> <snip for clarity>
>>>>
>>>>> I'd be wondering, however, if
>>>>> it might get the crank going in the wrong direction, hence the need for a
>>>>> motor to ensure proper rotation.
>>>>
>>>> good point. this is likely because as an engine stops rotating on
>>>> shutdown, it "bumps" up against compressed mixture on whatever piston is
>>>> in the compression stroke, and stops /before/ tdc, not after. even if
>>>> the mixture could be ignited cold, the piston would have to be
>>>> positioned after tdc, not before.
>>>
>>>
>>> Actually that is not necessarily the case.
>>>
>>> The one engine i have seen that would self start looked like it would run
>>> backwards for something 90-140 degrees and then reverse and run forward.
>>
>> then you had a serious carburetor problem dumping vast excess gas.
>
> No, The only thing unusual about the engine was that it had very low
> resistance. When warm you could push on the fan with one finger and get
> the engine to turn.
>
> As for extra gas. There is always excess gas pumped into the exhaust when
> you shut off the engine.

when talking about carburetion, "excess" means "in excess of the air
supply". which is why i tried to dumb it down to "dumping gas" earlier.
apparently i didn't succeed in my objective.


>
>
>> the
>> only way a gasoline engine can "run backwards" is if it's getting fuel
>> from the exhaust.
>
> Of course there is gas in the exhaust. What did you think happened when
> you turn the engine off? There are a few engines designed with a solenoid
> in the carb that cut off the flow when ignition is turned off, but most
> engines just keep sucking gas until the engine stops turning.
>
>> if you're dumping unmetered gas so it's accumulating
>> in the exhaust, it might run as long as that fuel vapor can exist in the
>> pipe, but beyond that, it's game over.
>
> It didn't run backwards. It started by turning backwards about a 1/4-1/2
> revolution and then reversing and running forward.

uh huh.


> Sometimes it would not
> reverse, but run for one or two revolutions backwards and sometimes when
> you turned the key back to on it would do like most engines (which is
> nothing).
>
>>
>>>
>>> If you turned the warmed-up engine off and waited about 2 seconds and
>>> turned it on it would sometimes start right up. Sometimes it would kick
>>> back and blow smoke out the air intake and sometimes it would kick-back
>>> and then reverse and start running. And sometimes it would just do
>>> nothing when you turned the key back to on.
>>>
>>> This was an IH engine with carburetor and points.
>>>
>>> -jim
>>
>> historically, many [diesels - see above] engines have been able to "run
>> backwards".
>
> I didn't say the engine "ran backwards" at least not for any amount of
> time. The engine revolved in the reverse direction for less than 1/2 turn
> and then changed direction and started up and ran normally. This was on a
> step-van so with the engine cover off you were sitting right next to the
> engine and you could watch the fan turn.

sure, i believe in the magical flywheel changing its angular momentum
too, because everybody knows how flywheels got their name - they
inexplicably fly backwards and forwards!


--
nomina rutrum rutrum

jim beam wrote:

> sure, i believe in the magical flywheel changing its angular momentum
> too, because everybody knows how flywheels got their name - they
> inexplicably fly backwards and forwards!
>

Lots a people ended up with a broken arm when that happened on the old
hand crank engines. And they had heavy flywheels.

On 09/10/2011 01:27 PM, jim wrote:
>
>
> jim beam wrote:
>
>> sure, i believe in the magical flywheel changing its angular momentum
>> too, because everybody knows how flywheels got their name - they
>> inexplicably fly backwards and forwards!
>>
>
> Lots a people ended up with a broken arm when that happened on the old
> hand crank engines. And they had heavy flywheels.

even old hand crank engines had ratchets. and that was to protect
against a weak cranker bouncing back off compression, not spontaneously
changing direction of spin.


--
nomina rutrum rutrum

jim beam wrote:
>
> On 09/10/2011 01:27 PM, jim wrote:
> >
> >
> > jim beam wrote:
> >
> >> sure, i believe in the magical flywheel changing its angular momentum
> >> too, because everybody knows how flywheels got their name - they
> >> inexplicably fly backwards and forwards!
> >>
> >
> > Lots a people ended up with a broken arm when that happened on the old
> > hand crank engines. And they had heavy flywheels.
>
> even old hand crank engines had ratchets.

Most of them didn't.

> and that was to protect
> against a weak cranker bouncing back off compression, not spontaneously
> changing direction of spin.

"bouncing back off compression " = "changing direction of spin"

jim wrote:
>

>
> > and that was to protect
> > against a weak cranker bouncing back off compression, not spontaneously
> > changing direction of spin.
>
> "bouncing back off compression " = "changing direction of spin"

I should add that it wasn't bouncing back on compression, it was the
cylinder firing before it got to TDC that caused the engine to reverse
direction and break arms.

http://www.devilfinder.com/find.php?...a+Ford+Model+T

Tin Lizzies have been known to run people down after starting them
up.Thank Gawd for the electric motor.
cuhulin

jim beam wrote:

> >
> > It didn't run backwards. It started by turning backwards about a 1/4-1/2
> > revolution and then reversing and running forward.
>
> uh huh.
>

Here is a movie of starting an engine by turning it backwards and then it
reverses direction and starts.
And notice the flywheel is huge
I knew somebody would have that on film because lots of old tractors used
to start like this.

http://www.youtube.com/watch?v=VWuhl-bcWFE

On Sep 9, 12:16*am, "larry moe 'n curly" >
wrote:
> Are any cars currently in production with direct injection designed so
> they can be be started even if the starter motor doesn't work, at
> least in most cases, by having the computer choose a cylinder that has
> its valves closed and its pistons in the power stroke position? * At
> least are direct injection cars designed to help the starter by doing
> that?

Mazda SISS. However, it is unclear whether this technology actually
made it into production cars. Mazda seems to have planned to introduce
it in 2009, but did it actually happen?

http://www.mazda.com/mazdaspirit/env/engine/siss.html

On 09/12/2011 01:07 PM, Ed Treijs wrote:
> On Sep 9, 12:16�am, "larry moe 'n >
> wrote:
>> Are any cars currently in production with direct injection designed so
>> they can be be started even if the starter motor doesn't work, at
>> least in most cases, by having the computer choose a cylinder that has
>> its valves closed and its pistons in the power stroke position? � At
>> least are direct injection cars designed to help the starter by doing
>> that?
>
> Mazda SISS. However, it is unclear whether this technology actually
> made it into production cars. Mazda seems to have planned to introduce
> it in 2009, but did it actually happen?
>
> http://www.mazda.com/mazdaspirit/env/engine/siss.html

the two pain points to take away from that link a

1. the engine has to be stopped with a piston /after/ tdc, which is no
small control issue.

2. the engine needs to be hot.

neither of which are going to make the conventional starter motor go
away any time soon [and certainly not for diesels], unless we all just
go for hybid technology and be done with it.

--
nomina rutrum rutrum