[original post is likely clipped to save bandwidth]
On Thu, 26 Jan 2006 22:51:23 GMT, Matt Whiting <whiting@epix.net> wrote:

>gerry wrote:
>> [original post is likely clipped to save bandwidth]
>> On Wed, 25 Jan 2006 21:40:08 GMT, Matt Whiting <whiting@epix.net> wrote:
>>
>>
>>>Rob wrote:
>>>
>>>
>>>> I have noticed a slight valve chatter with regular gas. It goes away with
>>>>mid-level grade gas. Anyone else notice this. '06 Sonata LX (V6)
>>>>
>>>
>>>I don't think fuel octane can have any bearing on the valve train. What
>>>you are hearing typically is detonation, commonly called "pinging."
>>>Typically, this will increase with more throttle at a given speed or at
>>>lower RPMs (lugging).
>>
>>
>> Octane increasing additives are used EXPLICITLY to reduce pinging or
>> premature detonation. That is actually the only value with higher octane
>> fuels since they have lower energy content than low octane fuels.
>
>True, but what is your point? This has nothing to do with the VALVE
>train, which was my point.
>
>And there is no such thing is premature detonation. There is
>preignition and there is detonation, there isn't premature detonation.
>All detonation is undesirable, no matter when it occurs.


Seems we just are playing with words here An internal combustion engine
detonates it's charge. It is fairly violent compared to igniting a gas
burner in a furnace, thus "detonation" is a reasonable word for "ignition"
in this context.Whichever word you prefer, I believe we can agree
"initiation of combustion" and it's timing, speed of progression and cause
is what matters.


>> Higher octane fuel may allow particular engines that need them perform
>> better thus offsetting the lower energy content for those engines.
>
>True. Most modern engines have knock sensors to detect detonation.
>When this is detected the engine control computer will typically retard
>the timing until the pinging stops. This will reduce the performance of
>the engine. If higher octane fuel prevents this, then it can increase
>the performance of such an engine.

>But this still has nothing to do with the valve train. :-)

If the valves "chatter" with lower octane fuel as indicated in the
original post but do not with higher octane fuel, it has something to do
with the charge igniting before it should or the flame (blast) front
traveling too fast. Delay in ignition or speed of the flame front is the
only thing higher octane fuel changes.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

 

gerry wrote:

> [original post is likely clipped to save bandwidth]
> On Thu, 26 Jan 2006 22:51:23 GMT, Matt Whiting <whiting@epix.net> wrote:
>
>
>>gerry wrote:
>>
>>>[original post is likely clipped to save bandwidth]
>>>On Wed, 25 Jan 2006 21:40:08 GMT, Matt Whiting <whiting@epix.net> wrote:
>>>
>>>
>>>
>>>>Rob wrote:
>>>>
>>>>
>>>>
>>>>>I have noticed a slight valve chatter with regular gas. It goes away with
>>>>>mid-level grade gas. Anyone else notice this. '06 Sonata LX (V6)
>>>>>
>>>>
>>>>I don't think fuel octane can have any bearing on the valve train. What
>>>>you are hearing typically is detonation, commonly called "pinging."
>>>>Typically, this will increase with more throttle at a given speed or at
>>>>lower RPMs (lugging).
>>>
>>>
>>>Octane increasing additives are used EXPLICITLY to reduce pinging or
>>>premature detonation. That is actually the only value with higher octane
>>>fuels since they have lower energy content than low octane fuels.
>>
>>True, but what is your point? This has nothing to do with the VALVE
>>train, which was my point.
>>
>>And there is no such thing is premature detonation. There is
>>preignition and there is detonation, there isn't premature detonation.
>>All detonation is undesirable, no matter when it occurs.
>
>
>
> Seems we just are playing with words here An internal combustion engine
> detonates it's charge. It is fairly violent compared to igniting a gas
> burner in a furnace, thus "detonation" is a reasonable word for "ignition"
> in this context.Whichever word you prefer, I believe we can agree
> "initiation of combustion" and it's timing, speed of progression and cause
> is what matters.

No, an internal combustion engine ignites its charge and burns it. Yes,
it burns very fast, but it is a burn, not an explosion, which is what
detonation is. Detonation and combustion aren't the same thing with
respect to an IC engine.


>>>Higher octane fuel may allow particular engines that need them perform
>>>better thus offsetting the lower energy content for those engines.
>>
>>True. Most modern engines have knock sensors to detect detonation.
>>When this is detected the engine control computer will typically retard
>>the timing until the pinging stops. This will reduce the performance of
>>the engine. If higher octane fuel prevents this, then it can increase
>>the performance of such an engine.
>
>
>>But this still has nothing to do with the valve train. :-)
>
>
> If the valves "chatter" with lower octane fuel as indicated in the
> original post but do not with higher octane fuel, it has something to do
> with the charge igniting before it should or the flame (blast) front
> traveling too fast. Delay in ignition or speed of the flame front is the
> only thing higher octane fuel changes.

My point is that either the valves weren't chattering and the OP was
hearing detonation, or the valves are making noise and something is
wrong other than octane. The two simply aren't related. The valves are
closed against their seats when the combustion (or detonation) occurs.


Matt

 

gerry wrote:

> [original post is likely clipped to save bandwidth]
> On Thu, 26 Jan 2006 22:51:23 GMT, Matt Whiting <whiting@epix.net> wrote:
>
>
>>gerry wrote:
>>
>>>[original post is likely clipped to save bandwidth]
>>>On Wed, 25 Jan 2006 21:40:08 GMT, Matt Whiting <whiting@epix.net> wrote:
>>>
>>>
>>>
>>>>Rob wrote:
>>>>
>>>>
>>>>
>>>>>I have noticed a slight valve chatter with regular gas. It goes away with
>>>>>mid-level grade gas. Anyone else notice this. '06 Sonata LX (V6)
>>>>>
>>>>
>>>>I don't think fuel octane can have any bearing on the valve train. What
>>>>you are hearing typically is detonation, commonly called "pinging."
>>>>Typically, this will increase with more throttle at a given speed or at
>>>>lower RPMs (lugging).
>>>
>>>
>>>Octane increasing additives are used EXPLICITLY to reduce pinging or
>>>premature detonation. That is actually the only value with higher octane
>>>fuels since they have lower energy content than low octane fuels.
>>
>>True, but what is your point? This has nothing to do with the VALVE
>>train, which was my point.
>>
>>And there is no such thing is premature detonation. There is
>>preignition and there is detonation, there isn't premature detonation.
>>All detonation is undesirable, no matter when it occurs.
>
>
>
> Seems we just are playing with words here An internal combustion engine
> detonates it's charge. It is fairly violent compared to igniting a gas
> burner in a furnace, thus "detonation" is a reasonable word for "ignition"
> in this context.Whichever word you prefer, I believe we can agree
> "initiation of combustion" and it's timing, speed of progression and cause
> is what matters.

No, an internal combustion engine ignites its charge and burns it. Yes,
it burns very fast, but it is a burn, not an explosion, which is what
detonation is. Detonation and combustion aren't the same thing with
respect to an IC engine.


>>>Higher octane fuel may allow particular engines that need them perform
>>>better thus offsetting the lower energy content for those engines.
>>
>>True. Most modern engines have knock sensors to detect detonation.
>>When this is detected the engine control computer will typically retard
>>the timing until the pinging stops. This will reduce the performance of
>>the engine. If higher octane fuel prevents this, then it can increase
>>the performance of such an engine.
>
>
>>But this still has nothing to do with the valve train. :-)
>
>
> If the valves "chatter" with lower octane fuel as indicated in the
> original post but do not with higher octane fuel, it has something to do
> with the charge igniting before it should or the flame (blast) front
> traveling too fast. Delay in ignition or speed of the flame front is the
> only thing higher octane fuel changes.

My point is that either the valves weren't chattering and the OP was
hearing detonation, or the valves are making noise and something is
wrong other than octane. The two simply aren't related. The valves are
closed against their seats when the combustion (or detonation) occurs.


Matt

 

gerry wrote:

> [original post is likely clipped to save bandwidth]
> On Thu, 26 Jan 2006 22:51:23 GMT, Matt Whiting <whiting@epix.net> wrote:
>
>
>>gerry wrote:
>>
>>>[original post is likely clipped to save bandwidth]
>>>On Wed, 25 Jan 2006 21:40:08 GMT, Matt Whiting <whiting@epix.net> wrote:
>>>
>>>
>>>
>>>>Rob wrote:
>>>>
>>>>
>>>>
>>>>>I have noticed a slight valve chatter with regular gas. It goes away with
>>>>>mid-level grade gas. Anyone else notice this. '06 Sonata LX (V6)
>>>>>
>>>>
>>>>I don't think fuel octane can have any bearing on the valve train. What
>>>>you are hearing typically is detonation, commonly called "pinging."
>>>>Typically, this will increase with more throttle at a given speed or at
>>>>lower RPMs (lugging).
>>>
>>>
>>>Octane increasing additives are used EXPLICITLY to reduce pinging or
>>>premature detonation. That is actually the only value with higher octane
>>>fuels since they have lower energy content than low octane fuels.
>>
>>True, but what is your point? This has nothing to do with the VALVE
>>train, which was my point.
>>
>>And there is no such thing is premature detonation. There is
>>preignition and there is detonation, there isn't premature detonation.
>>All detonation is undesirable, no matter when it occurs.
>
>
>
> Seems we just are playing with words here An internal combustion engine
> detonates it's charge. It is fairly violent compared to igniting a gas
> burner in a furnace, thus "detonation" is a reasonable word for "ignition"
> in this context.Whichever word you prefer, I believe we can agree
> "initiation of combustion" and it's timing, speed of progression and cause
> is what matters.

No, an internal combustion engine ignites its charge and burns it. Yes,
it burns very fast, but it is a burn, not an explosion, which is what
detonation is. Detonation and combustion aren't the same thing with
respect to an IC engine.


>>>Higher octane fuel may allow particular engines that need them perform
>>>better thus offsetting the lower energy content for those engines.
>>
>>True. Most modern engines have knock sensors to detect detonation.
>>When this is detected the engine control computer will typically retard
>>the timing until the pinging stops. This will reduce the performance of
>>the engine. If higher octane fuel prevents this, then it can increase
>>the performance of such an engine.
>
>
>>But this still has nothing to do with the valve train. :-)
>
>
> If the valves "chatter" with lower octane fuel as indicated in the
> original post but do not with higher octane fuel, it has something to do
> with the charge igniting before it should or the flame (blast) front
> traveling too fast. Delay in ignition or speed of the flame front is the
> only thing higher octane fuel changes.

My point is that either the valves weren't chattering and the OP was
hearing detonation, or the valves are making noise and something is
wrong other than octane. The two simply aren't related. The valves are
closed against their seats when the combustion (or detonation) occurs.


Matt

 

> gerry wrote:

>> Seems we just are playing with words here An internal combustion
>> engine
>> detonates it's charge. It is fairly violent compared to igniting a gas
>> burner in a furnace, thus "detonation" is a reasonable word for
>> "ignition"
>> in this context.Whichever word you prefer, I believe we can agree
>> "initiation of combustion" and it's timing, speed of progression and
>> cause
>> is what matters.


Here is a nice tutorial on the subject:

http://www.streetrodstuff.com/Articl...ne/Detonation/

As you can see, detonation is not a reasonable word for ignition.


Matt

 

> gerry wrote:

>> Seems we just are playing with words here An internal combustion
>> engine
>> detonates it's charge. It is fairly violent compared to igniting a gas
>> burner in a furnace, thus "detonation" is a reasonable word for
>> "ignition"
>> in this context.Whichever word you prefer, I believe we can agree
>> "initiation of combustion" and it's timing, speed of progression and
>> cause
>> is what matters.


Here is a nice tutorial on the subject:

http://www.streetrodstuff.com/Articl...ne/Detonation/

As you can see, detonation is not a reasonable word for ignition.


Matt

 

> gerry wrote:

>> Seems we just are playing with words here An internal combustion
>> engine
>> detonates it's charge. It is fairly violent compared to igniting a gas
>> burner in a furnace, thus "detonation" is a reasonable word for
>> "ignition"
>> in this context.Whichever word you prefer, I believe we can agree
>> "initiation of combustion" and it's timing, speed of progression and
>> cause
>> is what matters.


Here is a nice tutorial on the subject:

http://www.streetrodstuff.com/Articl...ne/Detonation/

As you can see, detonation is not a reasonable word for ignition.


Matt

 

[original post is likely clipped to save bandwidth]
On Fri, 27 Jan 2006 02:52:05 GMT, Matt Whiting <whiting@epix.net> wrote:

>
>> gerry wrote:
>
>>> Seems we just are playing with words here An internal combustion
>>> engine
>>> detonates it's charge. It is fairly violent compared to igniting a gas
>>> burner in a furnace, thus "detonation" is a reasonable word for
>>> "ignition"
>>> in this context.Whichever word you prefer, I believe we can agree
>>> "initiation of combustion" and it's timing, speed of progression and
>>> cause
>>> is what matters.
>
>
>Here is a nice tutorial on the subject:
>
>http://www.streetrodstuff.com/Articl...ne/Detonation/
>
>As you can see, detonation is not a reasonable word for ignition.


Look up " detonate" in a good dictionary and you will find it is not as
defined as used in the above reference! It is not "spontaneous
combustion"!

An example is

http://www.yourdictionary.com/ahd/d/d0172500.html

"To explode or cause to explode."

http://en.wikipedia.org/wiki/Detonate

states

"involves a shock wave and a reaction zone behind it"

Indeed one detonates a thermo nuclear weapon and that sure is not
spontaneous combustion as defined in the reference you choose

This is just to point out that different groups use different jargon. Thus
I indicated not to worry too much about folks using different wording. I
concede I use the words in more general engineering context, not
automotive jargon.

In context of this discussion and using your choice of wording, octane
affects both "pre-ignition" and "detonation", inhibiting both.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

 

[original post is likely clipped to save bandwidth]
On Fri, 27 Jan 2006 02:52:05 GMT, Matt Whiting <whiting@epix.net> wrote:

>
>> gerry wrote:
>
>>> Seems we just are playing with words here An internal combustion
>>> engine
>>> detonates it's charge. It is fairly violent compared to igniting a gas
>>> burner in a furnace, thus "detonation" is a reasonable word for
>>> "ignition"
>>> in this context.Whichever word you prefer, I believe we can agree
>>> "initiation of combustion" and it's timing, speed of progression and
>>> cause
>>> is what matters.
>
>
>Here is a nice tutorial on the subject:
>
>http://www.streetrodstuff.com/Articl...ne/Detonation/
>
>As you can see, detonation is not a reasonable word for ignition.


Look up " detonate" in a good dictionary and you will find it is not as
defined as used in the above reference! It is not "spontaneous
combustion"!

An example is

http://www.yourdictionary.com/ahd/d/d0172500.html

"To explode or cause to explode."

http://en.wikipedia.org/wiki/Detonate

states

"involves a shock wave and a reaction zone behind it"

Indeed one detonates a thermo nuclear weapon and that sure is not
spontaneous combustion as defined in the reference you choose

This is just to point out that different groups use different jargon. Thus
I indicated not to worry too much about folks using different wording. I
concede I use the words in more general engineering context, not
automotive jargon.

In context of this discussion and using your choice of wording, octane
affects both "pre-ignition" and "detonation", inhibiting both.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

 

[original post is likely clipped to save bandwidth]
On Fri, 27 Jan 2006 02:52:05 GMT, Matt Whiting <whiting@epix.net> wrote:

>
>> gerry wrote:
>
>>> Seems we just are playing with words here An internal combustion
>>> engine
>>> detonates it's charge. It is fairly violent compared to igniting a gas
>>> burner in a furnace, thus "detonation" is a reasonable word for
>>> "ignition"
>>> in this context.Whichever word you prefer, I believe we can agree
>>> "initiation of combustion" and it's timing, speed of progression and
>>> cause
>>> is what matters.
>
>
>Here is a nice tutorial on the subject:
>
>http://www.streetrodstuff.com/Articl...ne/Detonation/
>
>As you can see, detonation is not a reasonable word for ignition.


Look up " detonate" in a good dictionary and you will find it is not as
defined as used in the above reference! It is not "spontaneous
combustion"!

An example is

http://www.yourdictionary.com/ahd/d/d0172500.html

"To explode or cause to explode."

http://en.wikipedia.org/wiki/Detonate

states

"involves a shock wave and a reaction zone behind it"

Indeed one detonates a thermo nuclear weapon and that sure is not
spontaneous combustion as defined in the reference you choose

This is just to point out that different groups use different jargon. Thus
I indicated not to worry too much about folks using different wording. I
concede I use the words in more general engineering context, not
automotive jargon.

In context of this discussion and using your choice of wording, octane
affects both "pre-ignition" and "detonation", inhibiting both.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

 

[original post is likely clipped to save bandwidth]
On Fri, 27 Jan 2006 02:42:51 GMT, Matt Whiting <whiting@epix.net> wrote:


>My point is that either the valves weren't chattering and the OP was
>hearing detonation, or the valves are making noise and something is
>wrong other than octane. The two simply aren't related. The valves are
>closed against their seats when the combustion (or detonation) occurs.
>
>
>Matt

Read the reference you posted

http://www.streetrodstuff.com/Articl...ion/Page_2.php

According to that, "detonation"

"can actually cause fracture of valves-intake or exhaust"

The resonance can cause the valves to unseat briefly and force them closed
with force.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

 

[original post is likely clipped to save bandwidth]
On Fri, 27 Jan 2006 02:42:51 GMT, Matt Whiting <whiting@epix.net> wrote:


>My point is that either the valves weren't chattering and the OP was
>hearing detonation, or the valves are making noise and something is
>wrong other than octane. The two simply aren't related. The valves are
>closed against their seats when the combustion (or detonation) occurs.
>
>
>Matt

Read the reference you posted

http://www.streetrodstuff.com/Articl...ion/Page_2.php

According to that, "detonation"

"can actually cause fracture of valves-intake or exhaust"

The resonance can cause the valves to unseat briefly and force them closed
with force.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

 

[original post is likely clipped to save bandwidth]
On Fri, 27 Jan 2006 02:42:51 GMT, Matt Whiting <whiting@epix.net> wrote:


>My point is that either the valves weren't chattering and the OP was
>hearing detonation, or the valves are making noise and something is
>wrong other than octane. The two simply aren't related. The valves are
>closed against their seats when the combustion (or detonation) occurs.
>
>
>Matt

Read the reference you posted

http://www.streetrodstuff.com/Articl...ion/Page_2.php

According to that, "detonation"

"can actually cause fracture of valves-intake or exhaust"

The resonance can cause the valves to unseat briefly and force them closed
with force.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

 

gerry wrote:

> Look up " detonate" in a good dictionary and you will find it is not as
> defined as used in the above reference! It is not "spontaneous
> combustion"!
>
> An example is
>
> http://www.yourdictionary.com/ahd/d/d0172500.html
>
> "To explode or cause to explode."
>
> http://en.wikipedia.org/wiki/Detonate
>
> states
>
> "involves a shock wave and a reaction zone behind it"

Detonation used in the automotive sense isn't all that different. The
spontaneous combustion is in effect an explosion. That is what makes
all of the noise. It is the shock wave hitting the cylinder walls,
piston and head that makes the racket.



> Indeed one detonates a thermo nuclear weapon and that sure is not
> spontaneous combustion as defined in the reference you choose
>
> This is just to point out that different groups use different jargon. Thus
> I indicated not to worry too much about folks using different wording. I
> concede I use the words in more general engineering context, not
> automotive jargon.

It makes sense to use automotive jargon when talking about an internal
combustion engine, which was the topic at hand.



> In context of this discussion and using your choice of wording, octane
> affects both "pre-ignition" and "detonation", inhibiting both.

Octane inhibits detonation, but has almost no affect on pre-ignition.
Pre-ignition typically occurs from hot spots in the combustion chamber.
Octane slows down the burn rate and lessens the chance of spontaneous
combustion, but it doesn't prevent hot spots and it doesn't prevent
ignition so it has littly if any affect on pre-ignition.


Matt

 

gerry wrote:

> Look up " detonate" in a good dictionary and you will find it is not as
> defined as used in the above reference! It is not "spontaneous
> combustion"!
>
> An example is
>
> http://www.yourdictionary.com/ahd/d/d0172500.html
>
> "To explode or cause to explode."
>
> http://en.wikipedia.org/wiki/Detonate
>
> states
>
> "involves a shock wave and a reaction zone behind it"

Detonation used in the automotive sense isn't all that different. The
spontaneous combustion is in effect an explosion. That is what makes
all of the noise. It is the shock wave hitting the cylinder walls,
piston and head that makes the racket.



> Indeed one detonates a thermo nuclear weapon and that sure is not
> spontaneous combustion as defined in the reference you choose
>
> This is just to point out that different groups use different jargon. Thus
> I indicated not to worry too much about folks using different wording. I
> concede I use the words in more general engineering context, not
> automotive jargon.

It makes sense to use automotive jargon when talking about an internal
combustion engine, which was the topic at hand.



> In context of this discussion and using your choice of wording, octane
> affects both "pre-ignition" and "detonation", inhibiting both.

Octane inhibits detonation, but has almost no affect on pre-ignition.
Pre-ignition typically occurs from hot spots in the combustion chamber.
Octane slows down the burn rate and lessens the chance of spontaneous
combustion, but it doesn't prevent hot spots and it doesn't prevent
ignition so it has littly if any affect on pre-ignition.


Matt