Can direct injection engines start without a starter motor?

Wouldn't all that stopping and starting of the engine put extra wear and
tear on the starter motor?
cuhulin

On 09/10/2011 04:52 PM, jim wrote:
>
>
> 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

er, it's a single cylinder. i hope you noticed that. there are many
more degrees of rotation to "bounce" off before you encounter another
compression stroke. as opposed to a 4. and most definitely as opposed
to an 8. assuming of course you also paid attention to the part about
the valve release...


--
nomina rutrum rutrum

On 09/10/2011 02:44 PM, jim wrote:
>
>
> 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,

then you don't understand what you were looking at, and this is a
pointless conversation. i should have looked at your handle and
realized this before responding since this seems to be the common thread
linking all your emissions on this group.


> it was the
> cylinder firing before it got to TDC that caused the engine to reverse
> direction and break arms.

in spite of the ratchet naturally...


--
nomina rutrum rutrum

jim beam wrote:
>
> On 09/10/2011 02:44 PM, jim wrote:
> >
> >
> > 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,
>
> then you don't understand what you were looking at, and this is a
> pointless conversation. i should have looked at your handle and
> realized this before responding since this seems to be the common thread
> linking all your emissions on this group.

Maybe you are the dummy.

The engine in the video does not bounce off compression
You can hear the engine fire and see that immediately causes
the engine to reverse the direction of spin.
They wouldn't have gone to all the trouble of getting the magneto
into position ready to trip if "bounce off compression" was
all that was needed.
The engine has to fire when turning in the reverse direction
for that method to start the engine
If the magneto fails to fire while turning backward it won't work.

>
> > it was the
> > cylinder firing before it got to TDC that caused the engine to reverse
> > direction and break arms.
>
> in spite of the ratchet naturally...

There was usually no ratchet you dummy.

And the point is the engine fires causing it to
accelerate in the opposite direction
That is more than just bouncing off compression

Bouncing off compression would of course be changing direction
also. But it isn't going to bounce off compression with
any more force than was used to create the compression

When the engine fires, causing a reversal of spin, that
produces a lot more spin in the opposite direction

jim beam wrote:
>
> On 09/10/2011 04:52 PM, jim wrote:
> >
> >
> > 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
>
> er, it's a single cylinder. i hope you noticed that. there are many
> more degrees of rotation to "bounce" off before you encounter another
> compression stroke. as opposed to a 4. and most definitely as opposed
> to an 8. assuming of course you also paid attention to the part about
> the valve release...

Did you forget what you said already?

"sure, i believe in the magical flywheel
changing its angular momentum "

There is nothing magical about an engine changing direction
of spin even when it has a massive flywheel.

The point of the video was to debunk your belief in magic flywheels
that you think prevent engines from reversing direstion.

The "valve release" has nothing to do with anything we are discussing
All that does is allow the engine to be rotated more easily.
A strong man can rotate the engine without the compression release
He shut the compression release back to off before starting the engine.
The compression release had nothing to do with
the engine changing direction of spin.

And this engine goes thru many compression strokes between firings
So you are wrong about that too.

This is a hit and miss engine. It does not fire after every compression
stroke. You can hear the engine fire only about every 20 revolutions
of the engine (by my count).
That is how it runs when idling
Every time it fires it speeds up and then slows down between "hits"
If the engine were put under a load it would start firing with fewer
"miss" cycles.
Under maximum load it would "hit" after every compression stroke.

And it did not just "bounce off" the compression
The engine fired when rotating backward and that caused the
engine to change direction of spin and propelled
the engine in the forward direction with sufficient energy to
get it past the next compression stroke and then it fired again
in the video you can hear each time the engine fires (pffffft!)
While idling it only fires about 5-6 times a minute.

Here is a good explanation of how hit-and-miss engines work

http://www.youtube.com/watch?v=tmQYIRLdeGM

On 09/13/2011 07:28 AM, jim wrote:
>
>
> jim beam wrote:
>>
>> On 09/10/2011 02:44 PM, jim wrote:
>>>
>>>
>>> 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,
>>
>> then you don't understand what you were looking at, and this is a
>> pointless conversation. i should have looked at your handle and
>> realized this before responding since this seems to be the common thread
>> linking all your emissions on this group.
>
> Maybe you are the dummy.
>
> The engine in the video does not bounce off compression

i said "then you don't understand what you were looking at" for a reason
- that's a cue for you to stop and think. i didn't say it just to have
to keep repeating.


> You can hear the engine fire and see that immediately causes
> the engine to reverse the direction of spin.
> They wouldn't have gone to all the trouble of getting the magneto
> into position ready to trip if "bounce off compression" was
> all that was needed.
> The engine has to fire when turning in the reverse direction
> for that method to start the engine
> If the magneto fails to fire while turning backward it won't work.
>
>>
>>> it was the
>>> cylinder firing before it got to TDC that caused the engine to reverse
>>> direction and break arms.
>>
>> in spite of the ratchet naturally...
>
> There was usually no ratchet you dummy.

"then you don't understand what you were looking at"


>
> And the point is the engine fires causing it to
> accelerate in the opposite direction
> That is more than just bouncing off compression
>
> Bouncing off compression would of course be changing direction
> also. But it isn't going to bounce off compression with
> any more force than was used to create the compression
>
> When the engine fires, causing a reversal of spin, that
> produces a lot more spin in the opposite direction

"then you don't understand what you were looking at"

i apologize - i'm a much greater "dummy" than you. i mistakenly
presumed you would read the above and stop to think. i was wrong and
will try not to confront you with "difficult" concepts again.


--
nomina rutrum rutrum

jim beam wrote:

> >
> > When the engine fires, causing a reversal of spin, that
> > produces a lot more spin in the opposite direction
>
> "then you don't understand what you were looking at"

Keep piling up the evidence that you are the dummy

It has nothing to do with what I'm "looking" at

In the video
http://www.youtube.com/watch?v=VWuhl-bcWFE
You can't see when the engine fires,
but you can hear when it fires
That pfffft sound you hear every once in a while
when it runs is the engine firing (it hits on that cycle)

It is called hit and miss engine because
it is designed to only fire when the engine speed drops
below a preset point.

When the video shows it being started
it fires once as he turns it backwards
that causes it to reverse direction and spin forward
then after the next compression stroke you can hear
it fire again. this is because the engine speed is
below the preset point.
After that it goes for maybe 8-10 seconds before it
fires for the third time.

I listened to the video again and by my count the
engine fired only 7 times during the video
You can see the engine speedup each time
you hear it fire.
It kind of sounds like a dog panting during the
cycles when the engine doesn't fire.

All of the above is observed by listening carefully
None of that is something you can tell by "looking"


Here is another video of a hit and miss engine starting
This one is designed a little different
on this one the operator has to manually trip the magneto
to get it to fire while turning it backward
He turns the engine backwards against compression and
as the compression builds he continues to push with his right hand
and slaps the magneto with is left hand and the engine fires and
changes direction and starts running.

http://www.youtube.com/watch?v=MIa40MADTpI

Any direct injection gasoline engine can start without a starter motor. They produce a high pressure(most injectors for GAS DIRECT INJECTION/or SIDI for GM)between 500 to 2900 PSI depending on the platform. The fuel injectors also run around 60 to 70 volts as opposed to the traditional 12v injectors.. They also have the ability to fire one to three times per event and run on compression rations of 11:1 to 13:1. They can run on multiple mods including stratified, stratefied homogeneous, homogeneous anti knock, homogeneous lean, and homogeneous.

2000(yes two thousand) psi is enough to turn a piston over.

On 11/14/2013 10:31 AM, wrote:
> Any direct injection gasoline engine can start without a starter
> motor. They produce a high pressure(most injectors for GAS DIRECT
> INJECTION/or SIDI for GM)between 500 to 2900 PSI depending on the
> platform. The fuel injectors also run around 60 to 70 volts as
> opposed to the traditional 12v injectors. They also have the ability
> to fire one to three times per event and run on compression rations
> of 11:1 to 13:1. They can run on multiple mods including stratified,
> stratefied homogeneous, homogeneous anti knock, homogeneous lean, and
> homogeneous.
>
> 2000(yes two thousand) psi is enough to turn a piston over.
>

I don't think that you'd want to spin the engine over by using fuel
pressure... the compression stroke would hydrolock the engine, which
tends to be detrimental to future functionality.

However, you do raise an interesting point, that with modern engine
controls, it might be possible for the engine computer to "know" which
piston is just past TDC on its power stroke, inject a small fuel charge
into that cylinder, then fire the plug, then proceed to the next
cylinder etc. until the engine is running normally. Sort of analogous
to an antique aircraft engine started with cartridges.

There must be a reason this approach is found lacking however -
immediate thoughts off the top of my head

1) there may not be enough oxygen in an uncompressed cylinder at TDC to
burn enough fuel to reliably spin the engine to the "next" cylinder,
especially if the engine is at operating temperature (e.g. after a short
fuel stop) as the air in the engine would be considerably less dense
than it would be at normal ambient temperatures.

2) Would rely on ECM memory to remember position of crankshaft and
camshaft until next starting event. If your battery goes flat over a
period of disuse, without a conventional starter motor it would be
impossible to start the engine without either push-starting or cranking
the engine by hand; not something I'd want to try with a high
compression 6-cylinder by myself. Alternately, a new kind of sensor
would have to be used which would allow the ECM to read cam position
relatively precisely at zero RPM.

To my knowledge nobody has implemented this approach yet; my
direct-injected BMW engine still has a conventional electric starter, as
does Hyundai's and every other mass produced DI engine.

HOWEVER - I'm finding this line of thought interesting, and if it could
work, would make an interesting ECM program addition for a backup
starting method in the event of an electric starter motor failure; sadly
not an uncommon issue with BMW N54/N55 engines from what I read on the
forums. Rather than leaving one stranded, such a scheme would result in
the engine starting but with an error message on the dashboard e.g.
"Starter motor failed, repair at earliest convenience" or something like
that.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Thursday, November 14, 2013 10:04:40 AM UTC-6, Nate Nagel wrote:
> On 11/14/2013 10:31 AM, wrote:
>
> > Any direct injection gasoline engine can start without a starter
>
> > motor. They produce a high pressure(most injectors for GAS DIRECT
>
> > INJECTION/or SIDI for GM)between 500 to 2900 PSI depending on the
>
> > platform. The fuel injectors also run around 60 to 70 volts as
>
> > opposed to the traditional 12v injectors. They also have the ability
>
> > to fire one to three times per event and run on compression rations
>
> > of 11:1 to 13:1. They can run on multiple mods including stratified,
>
> > stratefied homogeneous, homogeneous anti knock, homogeneous lean, and
>
> > homogeneous.
>
> >
>
> > 2000(yes two thousand) psi is enough to turn a piston over.
>
> >
>
>
>
> I don't think that you'd want to spin the engine over by using fuel
>
> pressure... the compression stroke would hydrolock the engine, which
>
> tends to be detrimental to future functionality.
>
>
>
> However, you do raise an interesting point, that with modern engine
>
> controls, it might be possible for the engine computer to "know" which
>
> piston is just past TDC on its power stroke, inject a small fuel charge
>
> into that cylinder, then fire the plug, then proceed to the next
>
> cylinder etc. until the engine is running normally. Sort of analogous
>
> to an antique aircraft engine started with cartridges.
>
>
>
> There must be a reason this approach is found lacking however -
>
> immediate thoughts off the top of my head
>
>
>
> 1) there may not be enough oxygen in an uncompressed cylinder at TDC to
>
> burn enough fuel to reliably spin the engine to the "next" cylinder,
>
> especially if the engine is at operating temperature (e.g. after a short
>
> fuel stop) as the air in the engine would be considerably less dense
>
> than it would be at normal ambient temperatures.
>
>
>
> 2) Would rely on ECM memory to remember position of crankshaft and
>
> camshaft until next starting event. If your battery goes flat over a
>
> period of disuse, without a conventional starter motor it would be
>
> impossible to start the engine without either push-starting or cranking
>
> the engine by hand; not something I'd want to try with a high
>
> compression 6-cylinder by myself. Alternately, a new kind of sensor
>
> would have to be used which would allow the ECM to read cam position
>
> relatively precisely at zero RPM.
>
>
>
> To my knowledge nobody has implemented this approach yet; my
>
> direct-injected BMW engine still has a conventional electric starter, as
>
> does Hyundai's and every other mass produced DI engine.
>
>
>
> HOWEVER - I'm finding this line of thought interesting, and if it could
>
> work, would make an interesting ECM program addition for a backup
>
> starting method in the event of an electric starter motor failure; sadly
>
> not an uncommon issue with BMW N54/N55 engines from what I read on the
>
> forums. Rather than leaving one stranded, such a scheme would result in
>
> the engine starting but with an error message on the dashboard e.g.
>
> "Starter motor failed, repair at earliest convenience" or something like
>
> that.
>
>
>
> nate
>
>
>
> --
>
> replace "roosters" with "cox" to reply.
>
> http://members.cox.net/njnagel

My T Model Ford car will be 100 years old in 2014