"jim beam" <spamvortex@bad.example.net> wrote in message
news:3n2%k.7837$E65.5071@fe02.news.easynews.com...
> On Sun, 07 Dec 2008 13:11:42 -0500, L Alpert wrote:
>
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:2WR_k.22788$k66.19344@fe03.news.easynews.com. ..
>>> On Sun, 07 Dec 2008 09:13:40 -0500, L Alpert wrote:
>>>
>>>> "Anon" <anonnospam@yahoo.net> wrote in message
>>>> news:OqOdnawJ9P6blabUnZ2dnUVZ_gqdnZ2d@giganews.com ...
>>>>>I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing belt
>>>>>breaks, will it cause extensive engine damage?
>>>>>
>>>>> The manual on the V6 is unclear when to change the belt it says to
>>>>> change it at 60,000 miles if you drive in very hot or cold
>>>>> conditions.
>>>>> I do not have a manual for the 4 cyl, it was a used car. It has
>>>>> 94,000
>>>>> on it now and runs perfectly.
>>>>>
>>>>>
>>>>>
>>>>>
>>>> I believe the recommended change period is 105K miles or 7 years under
>>>> normal conditions. My own interpretation of very hot has always been
>>>> desert type conditions (Death Valley, Sahara), very cold would be
>>>> similar to the northern Midwest areas and Canada/Alaska for the 60k
>>>> change.
>>>>
>>>> The key is not just the belt itself, but the internal cords/fibers
>>>> that
>>>> do not allow the belt to stretch, which are usually made from
>>>> Kevlar/Twaron (both are aramid type high tensile fibers). I'm not
>>>> sure
>>>> if the base OEM Honda belts are rubber, HSN or carbon fiber type (I
>>>> would suspect that they may be the one of the latter two, as at some
>>>> point in the 90's they increased the recommended belt change interval
>>>> by
>>>> a fairly large amount).
>>>>
>>>> Here are a couple of articles you may want to read....especially the
>>>> thermal properties of the Kevlar and interference engines.
>>>>
>>>> http://en.wikipedia.org/wiki/Timing_belt
>>>
>>> irc, kevlar is subject to accelerated fatigue when subject to humidity,
>>> so
>>> i believe the cords in high quality timing belts are usually glass
>>> fiber.
>>> the above link does allude to glass fiber use, although not in detail.
>>
>> "Glass fiber" is a misnomer, as it still uses a polymer carrier (ie,
>> flass filled kevlar) as far as I last was aware of.
>>
>> Polymer with 30%-33% glass fiber by weight is usually what you will find
>> in most industries. The higher percentages the more prone it will be to
>> fracture at a specific radius due to extremely high flex modulus.
>
> i fully admit to being rusty on this stuff, by why would you have a glass-
> filled aramid fiber??? there is no benefit that i can see unless you want
> to reduce elasticity of pure aramid, but the fatigue properties would
> suck. glass is plenty stiff and virtually fatigue proof if the surface is
> sufficiently protected. in which case, maybe you mean aramid /coated/
> glass fiber?

There are many applications for glass filled polymers. Depending on the
glass partical size and aspect ratios, it can greatly increase the
Young's/Flex modulus (stiffer) without greatly losing the material
properties (though there will be some loss). This will reduce part
elongation and increase tensile strength, as long as one doesn't go too far
and displace too much of the resin.

Glass filled polyamides and polycarbonates are used in a wide variety of
applications (mostly industrial).

As an example (fictitious in so much as I don't have the actual numbers in
front of me. I'd have to do some research to get real numbers as it's been
quite a few years since I've looked into this for an application), one can
use 10% glass fill in aramid fiber and reduce the elongation by a factor of
15%-25% and increase the tensile value by an almost equal amount, but add in
25% glass fiber, and these can values can be greatly reduced. Fatigue
properties would be dependent on each application as well, depending on the
expected bend radii needed, velocity, service temperature, glass particle
size/aspect ratio and other factors.

Carbon fibers and nano-clays are also used, though I believe glass is the
least costly.





>
>
>
>
>>
>>
>>>
>>>
>>>
>>>> http://en.wikipedia.org/wiki/Kevlar
>>>>
>>>> The potential damage from a broken belt is quite extensive,
>>>
>>> with an interference engine
>>>
>>>
>>>
>>>> and you may
>>>> or may not see any symptoms.
>>>
>>> ...prior to breakage.
>>>
>

 

On Mon, 08 Dec 2008 16:54:50 -0500, L Alpert wrote:

> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:3n2%k.7837$E65.5071@fe02.news.easynews.com...
>> On Sun, 07 Dec 2008 13:11:42 -0500, L Alpert wrote:
>>
>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>> news:2WR_k.22788$k66.19344@fe03.news.easynews.com. ..
>>>> On Sun, 07 Dec 2008 09:13:40 -0500, L Alpert wrote:
>>>>
>>>>> "Anon" <anonnospam@yahoo.net> wrote in message
>>>>> news:OqOdnawJ9P6blabUnZ2dnUVZ_gqdnZ2d@giganews.com ...
>>>>>>I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing
>>>>>>belt breaks, will it cause extensive engine damage?
>>>>>>
>>>>>> The manual on the V6 is unclear when to change the belt it says to
>>>>>> change it at 60,000 miles if you drive in very hot or cold
>>>>>> conditions.
>>>>>> I do not have a manual for the 4 cyl, it was a used car. It has
>>>>>> 94,000
>>>>>> on it now and runs perfectly.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>> I believe the recommended change period is 105K miles or 7 years
>>>>> under normal conditions. My own interpretation of very hot has
>>>>> always been desert type conditions (Death Valley, Sahara), very cold
>>>>> would be similar to the northern Midwest areas and Canada/Alaska for
>>>>> the 60k change.
>>>>>
>>>>> The key is not just the belt itself, but the internal cords/fibers
>>>>> that
>>>>> do not allow the belt to stretch, which are usually made from
>>>>> Kevlar/Twaron (both are aramid type high tensile fibers). I'm not
>>>>> sure
>>>>> if the base OEM Honda belts are rubber, HSN or carbon fiber type (I
>>>>> would suspect that they may be the one of the latter two, as at some
>>>>> point in the 90's they increased the recommended belt change
>>>>> interval by
>>>>> a fairly large amount).
>>>>>
>>>>> Here are a couple of articles you may want to read....especially the
>>>>> thermal properties of the Kevlar and interference engines.
>>>>>
>>>>> http://en.wikipedia.org/wiki/Timing_belt
>>>>
>>>> irc, kevlar is subject to accelerated fatigue when subject to
>>>> humidity, so
>>>> i believe the cords in high quality timing belts are usually glass
>>>> fiber.
>>>> the above link does allude to glass fiber use, although not in
>>>> detail.
>>>
>>> "Glass fiber" is a misnomer, as it still uses a polymer carrier (ie,
>>> flass filled kevlar) as far as I last was aware of.
>>>
>>> Polymer with 30%-33% glass fiber by weight is usually what you will
>>> find in most industries. The higher percentages the more prone it
>>> will be to fracture at a specific radius due to extremely high flex
>>> modulus.
>>
>> i fully admit to being rusty on this stuff, by why would you have a
>> glass- filled aramid fiber??? there is no benefit that i can see
>> unless you want to reduce elasticity of pure aramid, but the fatigue
>> properties would suck. glass is plenty stiff and virtually fatigue
>> proof if the surface is sufficiently protected. in which case, maybe
>> you mean aramid /coated/ glass fiber?
>
> There are many applications for glass filled polymers. Depending on the
> glass partical size and aspect ratios, it can greatly increase the
> Young's/Flex modulus (stiffer) without greatly losing the material
> properties (though there will be some loss). This will reduce part
> elongation and increase tensile strength, as long as one doesn't go too
> far and displace too much of the resin.
>
> Glass filled polyamides and polycarbonates are used in a wide variety
> of applications (mostly industrial).
>
> As an example (fictitious in so much as I don't have the actual numbers
> in front of me. I'd have to do some research to get real numbers as it's
> been quite a few years since I've looked into this for an application),
> one can use 10% glass fill in aramid fiber and reduce the elongation by
> a factor of 15%-25% and increase the tensile value by an almost equal
> amount, but add in 25% glass fiber, and these can values can be greatly
> reduced. Fatigue properties would be dependent on each application as
> well, depending on the expected bend radii needed, velocity, service
> temperature, glass particle size/aspect ratio and other factors.
>
> Carbon fibers and nano-clays are also used, though I believe glass is
> the least costly.

absolutely, understand all that. but small particle reinforcing, to my
incomplete understanding, doesn't serve well in a fatigue environment.
that is the kind of mechanism by which plastic radiators crack - great low
cycle mechanical properties, but when the load cycle gets up there,
fatigue romps away. i would therefore expect timing belt fiber, given
that it's subject to considerable repetitive strain many times that of
traditional small particle reinforced plastics, to have the most coherent
microstructure possible - no fillers. but i'm guessing.




>
>
>
>
>
>
>>
>>
>>
>>
>>>
>>>
>>>>
>>>>
>>>>> http://en.wikipedia.org/wiki/Kevlar
>>>>>
>>>>> The potential damage from a broken belt is quite extensive,
>>>>
>>>> with an interference engine
>>>>
>>>>
>>>>
>>>>> and you may
>>>>> or may not see any symptoms.
>>>>
>>>> ...prior to breakage.
>>>>
>>>>

 

On Sun, 07 Dec 2008 17:07:50 -0700, Michael Pardee wrote:

> "Greg Campbell" <nospam@null.net> wrote in message
> news:xeV_k.14049$v37.9929@newsfe01.iad...
>> Anon wrote:
>>
>>> I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing belt
>>> breaks, will it cause extensive engine damage?
>>
>> http://www.gates.com/part_locator/index.cfm?
location_id=3598&go=Interference
>
> Oddly, this is not completely accurate. My '85 Volvo had a provably
> non-interference engine (a Volvo guru even ran all the clearances with
> every available cam) but the list showed it to be interference. Hmm.

engine clearance of a hot engine at 6,000rpm is somewhat different to that
of a cold engine hand turned on the bench. if the manufacturer says it's
interference, i'd believe them.



>
>
>> Most belt driven Hondas run interfering valves that will be extremely
>> unhappy if the piston/valve timing fails.
>>
>>
> I love understatement!
>
>
>> Unless you can determine with some certainty that the belt has been
>> changed, you should start thinking about getting it done. As
>> mentioned, ~100K is the highest likely service interval. As the belt
>> ages, it will become statistically more likely to break. If it's a
>> 100K belt, you'd be 'fairly' safe for another 10~20K, (and it's not
>> 100% guaranteed to break at 150K.) But each passing mile increases the
>> odds (at an increasing rate!) of a VERY expensive boo-boo.
>>
>>
> Exactly so. Consider the logic of the situation: if you don't know when
> the belt is due and elect not to change it now, when will it be done? My
> guess is: too late. Once you change the belt you will know when the next
> one is due. And I can almost guarantee if the belt has been changed the
> seller will be showing you the receipt, because it adds value to the
> car.
>
> Mike

 

On Sun, 07 Dec 2008 20:56:38 -0600, Elliot Richmond wrote:

> On Sun, 7 Dec 2008 18:05:35 -0700, "Michael Pardee" <null@null.org>
> wrote:
>
>>of having to remove the head to get the plugs out. Apparently Ford has
>>released a TSB on removing the plugs: warm up the engine, loosen the
>>plugs about 3/4 turn, apply penetrant and let the engine cool... then,
>>good luck.
>
> I think something must have been left out. If one can loosen the plugs
> 3/4 turn, what's the problem? Just take 'em all the way out. Maybe I'm
> missing something.
>

yes. penetrant allows lube all the way down the tread. if it's galling
and dry, forcing the plug to turn can drag the whole thread out with it.
trust me on that.

 

On Sun, 07 Dec 2008 16:15:30 -0700, Tony Hwang wrote:

> Anon wrote:
>> "Tony Hwang" <dragon40@shaw.ca> wrote in message
>> news:i_X_k.12467$ED.7167@newsfe22.iad...
>>> Anon wrote:
>>>> Thanks to everyone that provided information and links.
>>>>
>>>> It really sucks that I'll have to spend $800-$1000 on my 2001 Honda
>>>> V6. The car only has 24000 miles on it but is 7 years old. That
>>>> almost makes me want to trade it in for a new car, one that doesn't
>>>> use a belt that cost mega bucks to change.
>>>>
>>>>
>>>>
>>> Hi,
>>> You have to see that belt change is time consuming and also it is good
>>> time to to the water pump while at it. Belt itself does not cost much.
>>> Some cars have timing chain.
>>
>> If Honda is going to use a part that must be changed as part of the
>> routine eminence schedule, it should be designed so it is easy to
>> change. I consider it poor design.
>>
>>
> Hmmm,
> Designing something involves many factors. It is not as simple as you
> might think. What is your definition of poor design? If you don't like
> to spend some $$ at 100K miles or so, is it poor design? I think not.

i think frod's desire to save a few cents by not having a compression
washer on their spark plugs is one of the most fundamentally retarded
design decisions of the 20th century. it's cost the consumer millions and
millions of dollars in munged heads and excess labor. and the thing is,
they knew it would be that way too! the pinto fiasco, the exploder
fiasco, red rear turn signals... frod management deserves a good hard
kicking in the *****.

 

"jim beam" <spamvortex@bad.example.net> wrote in message
news:jrm%k.18005$hm4.8627@fe05.news.easynews.com.. .
> On Sun, 07 Dec 2008 17:07:50 -0700, Michael Pardee wrote:
>
>> "Greg Campbell" <nospam@null.net> wrote in message
>> news:xeV_k.14049$v37.9929@newsfe01.iad...
>>> Anon wrote:
>>>
>>>> I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing belt
>>>> breaks, will it cause extensive engine damage?
>>>
>>> http://www.gates.com/part_locator/index.cfm?
> location_id=3598&go=Interference
>>
>> Oddly, this is not completely accurate. My '85 Volvo had a provably
>> non-interference engine (a Volvo guru even ran all the clearances with
>> every available cam) but the list showed it to be interference. Hmm.
>
> engine clearance of a hot engine at 6,000rpm is somewhat different to that
> of a cold engine hand turned on the bench. if the manufacturer says it's
> interference, i'd believe them.
>

The engine (B230F) is claimed by Volvo to be non-interference. See also
http://www.volvoclub.org.uk/faq/Engi...ferenceEngines
"The B230 series is non-interference with the exception of the B230E
[(high-compression B230 sold outside of North America)]."

 

"jim beam" <spamvortex@bad.example.net> wrote in message
news:Vom%k.18605$lT7.5936@fe04.news.easynews.com.. .
> On Mon, 08 Dec 2008 16:54:50 -0500, L Alpert wrote:
>
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:3n2%k.7837$E65.5071@fe02.news.easynews.com...
>>> On Sun, 07 Dec 2008 13:11:42 -0500, L Alpert wrote:
>>>
>>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>>> news:2WR_k.22788$k66.19344@fe03.news.easynews.com. ..
>>>>> On Sun, 07 Dec 2008 09:13:40 -0500, L Alpert wrote:
>>>>>
>>>>>> "Anon" <anonnospam@yahoo.net> wrote in message
>>>>>> news:OqOdnawJ9P6blabUnZ2dnUVZ_gqdnZ2d@giganews.com ...
>>>>>>>I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the
>>>>>>>timing
>>>>>>>belt breaks, will it cause extensive engine damage?
>>>>>>>
>>>>>>> The manual on the V6 is unclear when to change the belt it
>>>>>>> says to
>>>>>>> change it at 60,000 miles if you drive in very hot or cold
>>>>>>> conditions.
>>>>>>> I do not have a manual for the 4 cyl, it was a used car. It
>>>>>>> has
>>>>>>> 94,000
>>>>>>> on it now and runs perfectly.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> I believe the recommended change period is 105K miles or 7
>>>>>> years
>>>>>> under normal conditions. My own interpretation of very hot has
>>>>>> always been desert type conditions (Death Valley, Sahara), very
>>>>>> cold
>>>>>> would be similar to the northern Midwest areas and
>>>>>> Canada/Alaska for
>>>>>> the 60k change.
>>>>>>
>>>>>> The key is not just the belt itself, but the internal
>>>>>> cords/fibers
>>>>>> that
>>>>>> do not allow the belt to stretch, which are usually made from
>>>>>> Kevlar/Twaron (both are aramid type high tensile fibers). I'm
>>>>>> not
>>>>>> sure
>>>>>> if the base OEM Honda belts are rubber, HSN or carbon fiber
>>>>>> type (I
>>>>>> would suspect that they may be the one of the latter two, as at
>>>>>> some
>>>>>> point in the 90's they increased the recommended belt change
>>>>>> interval by
>>>>>> a fairly large amount).
>>>>>>
>>>>>> Here are a couple of articles you may want to
>>>>>> read....especially the
>>>>>> thermal properties of the Kevlar and interference engines.
>>>>>>
>>>>>> http://en.wikipedia.org/wiki/Timing_belt
>>>>>
>>>>> irc, kevlar is subject to accelerated fatigue when subject to
>>>>> humidity, so
>>>>> i believe the cords in high quality timing belts are usually
>>>>> glass
>>>>> fiber.
>>>>> the above link does allude to glass fiber use, although not in
>>>>> detail.
>>>>
>>>> "Glass fiber" is a misnomer, as it still uses a polymer carrier
>>>> (ie,
>>>> flass filled kevlar) as far as I last was aware of.
>>>>
>>>> Polymer with 30%-33% glass fiber by weight is usually what you
>>>> will
>>>> find in most industries. The higher percentages the more prone
>>>> it
>>>> will be to fracture at a specific radius due to extremely high
>>>> flex
>>>> modulus.
>>>
>>> i fully admit to being rusty on this stuff, by why would you have
>>> a
>>> glass- filled aramid fiber??? there is no benefit that i can see
>>> unless you want to reduce elasticity of pure aramid, but the
>>> fatigue
>>> properties would suck. glass is plenty stiff and virtually
>>> fatigue
>>> proof if the surface is sufficiently protected. in which case,
>>> maybe
>>> you mean aramid /coated/ glass fiber?
>>
>> There are many applications for glass filled polymers. Depending on
>> the
>> glass partical size and aspect ratios, it can greatly increase the
>> Young's/Flex modulus (stiffer) without greatly losing the material
>> properties (though there will be some loss). This will reduce part
>> elongation and increase tensile strength, as long as one doesn't go
>> too
>> far and displace too much of the resin.
>>
>> Glass filled polyamides and polycarbonates are used in a wide
>> variety
>> of applications (mostly industrial).
>>
>> As an example (fictitious in so much as I don't have the actual
>> numbers
>> in front of me. I'd have to do some research to get real numbers as
>> it's
>> been quite a few years since I've looked into this for an
>> application),
>> one can use 10% glass fill in aramid fiber and reduce the
>> elongation by
>> a factor of 15%-25% and increase the tensile value by an almost
>> equal
>> amount, but add in 25% glass fiber, and these can values can be
>> greatly
>> reduced. Fatigue properties would be dependent on each
>> application as
>> well, depending on the expected bend radii needed, velocity,
>> service
>> temperature, glass particle size/aspect ratio and other factors.
>>
>> Carbon fibers and nano-clays are also used, though I believe glass
>> is
>> the least costly.
>
> absolutely, understand all that. but small particle reinforcing, to
> my
> incomplete understanding, doesn't serve well in a fatigue
> environment.
> that is the kind of mechanism by which plastic radiators crack -
> great low
> cycle mechanical properties, but when the load cycle gets up there,
> fatigue romps away. i would therefore expect timing belt fiber,
> given
> that it's subject to considerable repetitive strain many times that
> of
> traditional small particle reinforced plastics, to have the most
> coherent
> microstructure possible - no fillers. but i'm guessing.

Usually, glass re-enforcement is within a binding matrix of a polymer.
Depending on the actual additive, percent used and the polymer, it may
not have a great negative affect on fatigue. I am not sure if plastic
radiators are a thermoplastic or a thermoset based structure, but the
aramids used are thermoset and do have different properties from a
thermoplastic.

I would think that without the binding polymer, 100% glass fiber would
be more prone to fatigue failure than with the binding polymer (think
of glass fiber optic cable vs. polymer fiber optic cable and bend
radius).

Of course (as I mentioned), it has been awhile since I have looked
into this application, and there may have been advancements made in
the use of long glass fiber with or without a binding polymer matrix.

>
>
>
>
>>
>>
>>
>>
>>
>>
>>>
>>>
>>>
>>>
>>>>
>>>>
>>>>>
>>>>>
>>>>>> http://en.wikipedia.org/wiki/Kevlar
>>>>>>
>>>>>> The potential damage from a broken belt is quite extensive,
>>>>>
>>>>> with an interference engine
>>>>>
>>>>>
>>>>>
>>>>>> and you may
>>>>>> or may not see any symptoms.
>>>>>
>>>>> ...prior to breakage.
>>>>>
>>>>>
>

 

L Alpert wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:Vom%k.18605$lT7.5936@fe04.news.easynews.com.. .
>> On Mon, 08 Dec 2008 16:54:50 -0500, L Alpert wrote:
>>
>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>> news:3n2%k.7837$E65.5071@fe02.news.easynews.com...
>>>> On Sun, 07 Dec 2008 13:11:42 -0500, L Alpert wrote:
>>>>
>>>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>>>> news:2WR_k.22788$k66.19344@fe03.news.easynews.com. ..
>>>>>> On Sun, 07 Dec 2008 09:13:40 -0500, L Alpert wrote:
>>>>>>
>>>>>>> "Anon" <anonnospam@yahoo.net> wrote in message
>>>>>>> news:OqOdnawJ9P6blabUnZ2dnUVZ_gqdnZ2d@giganews.com ...
>>>>>>>> I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the
>>>>>>>> timing
>>>>>>>> belt breaks, will it cause extensive engine damage?
>>>>>>>>
>>>>>>>> The manual on the V6 is unclear when to change the belt it
>>>>>>>> says to
>>>>>>>> change it at 60,000 miles if you drive in very hot or cold
>>>>>>>> conditions.
>>>>>>>> I do not have a manual for the 4 cyl, it was a used car. It
>>>>>>>> has
>>>>>>>> 94,000
>>>>>>>> on it now and runs perfectly.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> I believe the recommended change period is 105K miles or 7
>>>>>>> years
>>>>>>> under normal conditions. My own interpretation of very hot has
>>>>>>> always been desert type conditions (Death Valley, Sahara), very
>>>>>>> cold
>>>>>>> would be similar to the northern Midwest areas and
>>>>>>> Canada/Alaska for
>>>>>>> the 60k change.
>>>>>>>
>>>>>>> The key is not just the belt itself, but the internal
>>>>>>> cords/fibers
>>>>>>> that
>>>>>>> do not allow the belt to stretch, which are usually made from
>>>>>>> Kevlar/Twaron (both are aramid type high tensile fibers). I'm
>>>>>>> not
>>>>>>> sure
>>>>>>> if the base OEM Honda belts are rubber, HSN or carbon fiber
>>>>>>> type (I
>>>>>>> would suspect that they may be the one of the latter two, as at
>>>>>>> some
>>>>>>> point in the 90's they increased the recommended belt change
>>>>>>> interval by
>>>>>>> a fairly large amount).
>>>>>>>
>>>>>>> Here are a couple of articles you may want to
>>>>>>> read....especially the
>>>>>>> thermal properties of the Kevlar and interference engines.
>>>>>>>
>>>>>>> http://en.wikipedia.org/wiki/Timing_belt
>>>>>> irc, kevlar is subject to accelerated fatigue when subject to
>>>>>> humidity, so
>>>>>> i believe the cords in high quality timing belts are usually
>>>>>> glass
>>>>>> fiber.
>>>>>> the above link does allude to glass fiber use, although not in
>>>>>> detail.
>>>>> "Glass fiber" is a misnomer, as it still uses a polymer carrier
>>>>> (ie,
>>>>> flass filled kevlar) as far as I last was aware of.
>>>>>
>>>>> Polymer with 30%-33% glass fiber by weight is usually what you
>>>>> will
>>>>> find in most industries. The higher percentages the more prone
>>>>> it
>>>>> will be to fracture at a specific radius due to extremely high
>>>>> flex
>>>>> modulus.
>>>> i fully admit to being rusty on this stuff, by why would you have
>>>> a
>>>> glass- filled aramid fiber??? there is no benefit that i can see
>>>> unless you want to reduce elasticity of pure aramid, but the
>>>> fatigue
>>>> properties would suck. glass is plenty stiff and virtually
>>>> fatigue
>>>> proof if the surface is sufficiently protected. in which case,
>>>> maybe
>>>> you mean aramid /coated/ glass fiber?
>>> There are many applications for glass filled polymers. Depending on
>>> the
>>> glass partical size and aspect ratios, it can greatly increase the
>>> Young's/Flex modulus (stiffer) without greatly losing the material
>>> properties (though there will be some loss). This will reduce part
>>> elongation and increase tensile strength, as long as one doesn't go
>>> too
>>> far and displace too much of the resin.
>>>
>>> Glass filled polyamides and polycarbonates are used in a wide
>>> variety
>>> of applications (mostly industrial).
>>>
>>> As an example (fictitious in so much as I don't have the actual
>>> numbers
>>> in front of me. I'd have to do some research to get real numbers as
>>> it's
>>> been quite a few years since I've looked into this for an
>>> application),
>>> one can use 10% glass fill in aramid fiber and reduce the
>>> elongation by
>>> a factor of 15%-25% and increase the tensile value by an almost
>>> equal
>>> amount, but add in 25% glass fiber, and these can values can be
>>> greatly
>>> reduced. Fatigue properties would be dependent on each
>>> application as
>>> well, depending on the expected bend radii needed, velocity,
>>> service
>>> temperature, glass particle size/aspect ratio and other factors.
>>>
>>> Carbon fibers and nano-clays are also used, though I believe glass
>>> is
>>> the least costly.
>> absolutely, understand all that. but small particle reinforcing, to
>> my
>> incomplete understanding, doesn't serve well in a fatigue
>> environment.
>> that is the kind of mechanism by which plastic radiators crack -
>> great low
>> cycle mechanical properties, but when the load cycle gets up there,
>> fatigue romps away. i would therefore expect timing belt fiber,
>> given
>> that it's subject to considerable repetitive strain many times that
>> of
>> traditional small particle reinforced plastics, to have the most
>> coherent
>> microstructure possible - no fillers. but i'm guessing.
>
> Usually, glass re-enforcement is within a binding matrix of a polymer.
> Depending on the actual additive, percent used and the polymer, it may
> not have a great negative affect on fatigue. I am not sure if plastic
> radiators are a thermoplastic or a thermoset based structure, but the
> aramids used are thermoset and do have different properties from a
> thermoplastic.
>
> I would think that without the binding polymer, 100% glass fiber would
> be more prone to fatigue failure than with the binding polymer (think
> of glass fiber optic cable vs. polymer fiber optic cable and bend
> radius).

but glass pretty much doesn't fatigue afaik. it fractures if the
surface degrades, but that's not a fatigue mechanism as such.



>
> Of course (as I mentioned), it has been awhile since I have looked
> into this application, and there may have been advancements made in
> the use of long glass fiber with or without a binding polymer matrix.

just looked at the bosch automotive handbook - for positive drive belts,
they say "the tension member consists of twisted glass fibers". no
other materials details. under friction drive, they discuss nylon,
polyester and aramids - i think elasticity is a benefit in friction
drive, but not in toothed belts as it affects pitch and thus, wear.





>
>>
>>
>>
>>>
>>>
>>>
>>>
>>>
>>>>
>>>>
>>>>
>>>>>
>>>>>>
>>>>>>> http://en.wikipedia.org/wiki/Kevlar
>>>>>>>
>>>>>>> The potential damage from a broken belt is quite extensive,
>>>>>> with an interference engine
>>>>>>
>>>>>>
>>>>>>
>>>>>>> and you may
>>>>>>> or may not see any symptoms.
>>>>>> ...prior to breakage.
>>>>>>
>>>>>>
>
>

 

Michael Pardee wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:jrm%k.18005$hm4.8627@fe05.news.easynews.com.. .
>> On Sun, 07 Dec 2008 17:07:50 -0700, Michael Pardee wrote:
>>
>>> "Greg Campbell" <nospam@null.net> wrote in message
>>> news:xeV_k.14049$v37.9929@newsfe01.iad...
>>>> Anon wrote:
>>>>
>>>>> I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing belt
>>>>> breaks, will it cause extensive engine damage?
>>>> http://www.gates.com/part_locator/index.cfm?
>> location_id=3598&go=Interference
>>> Oddly, this is not completely accurate. My '85 Volvo had a provably
>>> non-interference engine (a Volvo guru even ran all the clearances with
>>> every available cam) but the list showed it to be interference. Hmm.
>> engine clearance of a hot engine at 6,000rpm is somewhat different to that
>> of a cold engine hand turned on the bench. if the manufacturer says it's
>> interference, i'd believe them.
>>
>
> The engine (B230F) is claimed by Volvo to be non-interference. See also
> http://www.volvoclub.org.uk/faq/Engi...ferenceEngines
> "The B230 series is non-interference with the exception of the B230E
> [(high-compression B230 sold outside of North America)]."
>
>

my argument is with the "provably" statement. cold bench != hot running.

 

"jim beam" <spamvortex@bad.example.net> wrote in message
news:ghlsra$6rs$1@news.motzarella.org...
>L Alpert wrote:
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:Vom%k.18605$lT7.5936@fe04.news.easynews.com.. .
>>> On Mon, 08 Dec 2008 16:54:50 -0500, L Alpert wrote:
>>>
>>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>>> news:3n2%k.7837$E65.5071@fe02.news.easynews.com...
>>>>> On Sun, 07 Dec 2008 13:11:42 -0500, L Alpert wrote:
>>>>>
>>>>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>>>>> news:2WR_k.22788$k66.19344@fe03.news.easynews.com. ..
>>>>>>> On Sun, 07 Dec 2008 09:13:40 -0500, L Alpert wrote:
>>>>>>>
>>>>>>>> "Anon" <anonnospam@yahoo.net> wrote in message
>>>>>>>> news:OqOdnawJ9P6blabUnZ2dnUVZ_gqdnZ2d@giganews.com ...
>>>>>>>>> I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing
>>>>>>>>> belt breaks, will it cause extensive engine damage?
>>>>>>>>>
>>>>>>>>> The manual on the V6 is unclear when to change the belt it says to
>>>>>>>>> change it at 60,000 miles if you drive in very hot or cold
>>>>>>>>> conditions.
>>>>>>>>> I do not have a manual for the 4 cyl, it was a used car. It has
>>>>>>>>> 94,000
>>>>>>>>> on it now and runs perfectly.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>> I believe the recommended change period is 105K miles or 7 years
>>>>>>>> under normal conditions. My own interpretation of very hot has
>>>>>>>> always been desert type conditions (Death Valley, Sahara), very
>>>>>>>> cold
>>>>>>>> would be similar to the northern Midwest areas and Canada/Alaska
>>>>>>>> for
>>>>>>>> the 60k change.
>>>>>>>>
>>>>>>>> The key is not just the belt itself, but the internal cords/fibers
>>>>>>>> that
>>>>>>>> do not allow the belt to stretch, which are usually made from
>>>>>>>> Kevlar/Twaron (both are aramid type high tensile fibers). I'm not
>>>>>>>> sure
>>>>>>>> if the base OEM Honda belts are rubber, HSN or carbon fiber type (I
>>>>>>>> would suspect that they may be the one of the latter two, as at
>>>>>>>> some
>>>>>>>> point in the 90's they increased the recommended belt change
>>>>>>>> interval by
>>>>>>>> a fairly large amount).
>>>>>>>>
>>>>>>>> Here are a couple of articles you may want to read....especially
>>>>>>>> the
>>>>>>>> thermal properties of the Kevlar and interference engines.
>>>>>>>>
>>>>>>>> http://en.wikipedia.org/wiki/Timing_belt
>>>>>>> irc, kevlar is subject to accelerated fatigue when subject to
>>>>>>> humidity, so
>>>>>>> i believe the cords in high quality timing belts are usually glass
>>>>>>> fiber.
>>>>>>> the above link does allude to glass fiber use, although not in
>>>>>>> detail.
>>>>>> "Glass fiber" is a misnomer, as it still uses a polymer carrier (ie,
>>>>>> flass filled kevlar) as far as I last was aware of.
>>>>>>
>>>>>> Polymer with 30%-33% glass fiber by weight is usually what you will
>>>>>> find in most industries. The higher percentages the more prone it
>>>>>> will be to fracture at a specific radius due to extremely high flex
>>>>>> modulus.
>>>>> i fully admit to being rusty on this stuff, by why would you have a
>>>>> glass- filled aramid fiber??? there is no benefit that i can see
>>>>> unless you want to reduce elasticity of pure aramid, but the fatigue
>>>>> properties would suck. glass is plenty stiff and virtually fatigue
>>>>> proof if the surface is sufficiently protected. in which case, maybe
>>>>> you mean aramid /coated/ glass fiber?
>>>> There are many applications for glass filled polymers. Depending on the
>>>> glass partical size and aspect ratios, it can greatly increase the
>>>> Young's/Flex modulus (stiffer) without greatly losing the material
>>>> properties (though there will be some loss). This will reduce part
>>>> elongation and increase tensile strength, as long as one doesn't go too
>>>> far and displace too much of the resin.
>>>>
>>>> Glass filled polyamides and polycarbonates are used in a wide variety
>>>> of applications (mostly industrial).
>>>>
>>>> As an example (fictitious in so much as I don't have the actual numbers
>>>> in front of me. I'd have to do some research to get real numbers as
>>>> it's
>>>> been quite a few years since I've looked into this for an application),
>>>> one can use 10% glass fill in aramid fiber and reduce the elongation by
>>>> a factor of 15%-25% and increase the tensile value by an almost equal
>>>> amount, but add in 25% glass fiber, and these can values can be greatly
>>>> reduced. Fatigue properties would be dependent on each application
>>>> as
>>>> well, depending on the expected bend radii needed, velocity, service
>>>> temperature, glass particle size/aspect ratio and other factors.
>>>>
>>>> Carbon fibers and nano-clays are also used, though I believe glass is
>>>> the least costly.
>>> absolutely, understand all that. but small particle reinforcing, to my
>>> incomplete understanding, doesn't serve well in a fatigue environment.
>>> that is the kind of mechanism by which plastic radiators crack - great
>>> low
>>> cycle mechanical properties, but when the load cycle gets up there,
>>> fatigue romps away. i would therefore expect timing belt fiber, given
>>> that it's subject to considerable repetitive strain many times that of
>>> traditional small particle reinforced plastics, to have the most
>>> coherent
>>> microstructure possible - no fillers. but i'm guessing.
>>
>> Usually, glass re-enforcement is within a binding matrix of a polymer.
>> Depending on the actual additive, percent used and the polymer, it may
>> not have a great negative affect on fatigue. I am not sure if plastic
>> radiators are a thermoplastic or a thermoset based structure, but the
>> aramids used are thermoset and do have different properties from a
>> thermoplastic.
>>
>> I would think that without the binding polymer, 100% glass fiber would be
>> more prone to fatigue failure than with the binding polymer (think of
>> glass fiber optic cable vs. polymer fiber optic cable and bend radius).
>
> but glass pretty much doesn't fatigue afaik. it fractures if the surface
> degrades, but that's not a fatigue mechanism as such.
>
>
>
>>
>> Of course (as I mentioned), it has been awhile since I have looked into
>> this application, and there may have been advancements made in the use
>> of long glass fiber with or without a binding polymer matrix.
>
> just looked at the bosch automotive handbook - for positive drive belts,
> they say "the tension member consists of twisted glass fibers". no other
> materials details. under friction drive, they discuss nylon, polyester
> and aramids - i think elasticity is a benefit in friction drive, but not
> in toothed belts as it affects pitch and thus, wear.

It is dependent on how much elasticity is allowable and the load needed. If
you go to www.matweb.com and enter a search term of "nylon 66" (I would hope
that you would get the same results as I did)...

If you look at item 13, this is general nylon 66 properties. For this, the
averages

ultimate tensile 99MPA
elongation at yield 9%
ultimate yield 51%.

If you look at item 19 (10% glass filled), the average values are

ultimate tensile 96.3MPA
elongation at yield 4.39%
ultimate elongation 5.08%

So the ultimate elongation is limited with only a minor impact to overall
tensile. If you look at item 20 (20% glass filled), the ultimate tensile is
reduced to 58%, which is a major impact to the overall strength, while
elongation at yield is 4% and at break is 4.32%, which further limits
elongation.

It would be faily easy to calcualte how much overall fiber is needed if the
tensile requirements are known and 4.39% elongation at yield and 5.08%
ultimate elongation meets the need of the application. The natural material
may even meet the a specific need as long as tensile at yield is high enough
(I probably should have included those values for comparison as well).

As far as fatigue is concerned, that may or may not be affected, depending
on use. Usually (but not always), fatigue is not greatly affected unless
tensile properties are greatly affected.

Once again, that's not to say that this is the case as far as a Honda timing
belt is concerned, they may be using something different.
I do know this is the case for the extruder drive belts that I use on my
equipment, which are timing belts, and they last much longer today then they
did 20 years ago.

>
>
>
>
>
>>
>>>
>>>
>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>>
>>>>>
>>>>>
>>>>>>
>>>>>>>
>>>>>>>> http://en.wikipedia.org/wiki/Kevlar
>>>>>>>>
>>>>>>>> The potential damage from a broken belt is quite extensive,
>>>>>>> with an interference engine
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> and you may
>>>>>>>> or may not see any symptoms.
>>>>>>> ...prior to breakage.
>>>>>>>
>>>>>>>
>>

 

"jim beam" <spamvortex@bad.example.net> wrote in message
news:ghltos$hpd$1@news.motzarella.org...
> Michael Pardee wrote:
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:jrm%k.18005$hm4.8627@fe05.news.easynews.com.. .
>>> On Sun, 07 Dec 2008 17:07:50 -0700, Michael Pardee wrote:
>>>
>>>> "Greg Campbell" <nospam@null.net> wrote in message
>>>> news:xeV_k.14049$v37.9929@newsfe01.iad...
>>>>> Anon wrote:
>>>>>
>>>>>> I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing
>>>>>> belt
>>>>>> breaks, will it cause extensive engine damage?
>>>>> http://www.gates.com/part_locator/index.cfm?
>>> location_id=3598&go=Interference
>>>> Oddly, this is not completely accurate. My '85 Volvo had a provably
>>>> non-interference engine (a Volvo guru even ran all the clearances with
>>>> every available cam) but the list showed it to be interference. Hmm.
>>> engine clearance of a hot engine at 6,000rpm is somewhat different to
>>> that
>>> of a cold engine hand turned on the bench. if the manufacturer says
>>> it's
>>> interference, i'd believe them.
>>>
>>
>> The engine (B230F) is claimed by Volvo to be non-interference. See also
>> http://www.volvoclub.org.uk/faq/Engi...ferenceEngines
>> "The B230 series is non-interference with the exception of the B230E
>> [(high-compression B230 sold outside of North America)]."
>
> my argument is with the "provably" statement. cold bench != hot running.
>
>

There were plenty of instances of timing belt failure when I was active in
the alt.autos.volvo forum - about like we see here. Those in the multi-valve
engines invariably resulted in engine damage while those in the earlier B230
engines never did. Over the decade or so I was active there that seems
pretty solid. It makes sense; with the standard cam the clearances were very
large. With the high lift cam (available in the UK as the "K" cam) you might
have a point, but not with anything available in North America.

Mike

 

Thus spake "L Alpert" <alpertl@xxgmail.com> :

>
>"Anon" <anonnospam@yahoo.net> wrote in message
>news:OqOdnawJ9P6blabUnZ2dnUVZ_gqdnZ2d@giganews.co m...
>>I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing
>>belt breaks, will it cause extensive engine damage?
>>
>> The manual on the V6 is unclear when to change the belt it says to
>> change it at 60,000 miles if you drive in very hot or cold
>> conditions. I do not have a manual for the 4 cyl, it was a used car.
>> It has 94,000 on it now and runs perfectly.
>>
>>
>>
>
>I believe the recommended change period is 105K miles or 7 years under
>normal conditions. My own interpretation of very hot has always been
>desert type conditions (Death Valley, Sahara), very cold would be
>similar to the northern Midwest areas and Canada/Alaska for the 60k
>change.

Not really. This year we (Austin, TX) had consistent highs of 100 or
more. And it's supposed to hit the low 30s/ high 20s tonight (it's 70
something at noon).

>
>The key is not just the belt itself, but the internal cords/fibers
>that do not allow the belt to stretch, which are usually made from
>Kevlar/Twaron (both are aramid type high tensile fibers). I'm not
>sure if the base OEM Honda belts are rubber, HSN or carbon fiber type
>(I would suspect that they may be the one of the latter two, as at
>some point in the 90's they increased the recommended belt change
>interval by a fairly large amount).
>
>Here are a couple of articles you may want to read....especially the
>thermal properties of the Kevlar and interference engines.
>
>http://en.wikipedia.org/wiki/Timing_belt
>http://en.wikipedia.org/wiki/Kevlar
>
>The potential damage from a broken belt is quite extensive, and you
>may or may not see any symptoms.

I think the phrase "complete engine rebuild" sums it up nicely
(badly?)

Kevlar is wonderful in both tension and compression. But once a
construction like a belt (or body armor) starts to fail, there's a
cascade effect.

>
>
>
--
- dillon I am not invalid

When you wish upon a falling star, your dreams come true.
Unless it's really a meteorite hurtling to the Earth which
will destroy all life. Then you're pretty much hosed no
matter what you wish for. Unless it's death by meteor.

 

"jim beam" <spamvortex@bad.example.net> wrote in message
news:Xym%k.10278$hx5.740@fe12.news.easynews.com...
> On Sun, 07 Dec 2008 16:15:30 -0700, Tony Hwang wrote:
>
>> Anon wrote:
>>> "Tony Hwang" <dragon40@shaw.ca> wrote in message
>>> news:i_X_k.12467$ED.7167@newsfe22.iad...
>>>> Anon wrote:
>>>>> Thanks to everyone that provided information and links.
>>>>>
>>>>> It really sucks that I'll have to spend $800-$1000 on my 2001 Honda
>>>>> V6. The car only has 24000 miles on it but is 7 years old. That
>>>>> almost makes me want to trade it in for a new car, one that doesn't
>>>>> use a belt that cost mega bucks to change.
>>>>>
>>>>>
>>>>>
>>>> Hi,
>>>> You have to see that belt change is time consuming and also it is good
>>>> time to to the water pump while at it. Belt itself does not cost much.
>>>> Some cars have timing chain.
>>>
>>> If Honda is going to use a part that must be changed as part of the
>>> routine eminence schedule, it should be designed so it is easy to
>>> change. I consider it poor design.
>>>
>>>
>> Hmmm,
>> Designing something involves many factors. It is not as simple as you
>> might think. What is your definition of poor design? If you don't like
>> to spend some $$ at 100K miles or so, is it poor design? I think not.
>
> i think frod's desire to save a few cents by not having a compression
> washer on their spark plugs is one of the most fundamentally retarded
> design decisions of the 20th century. it's cost the consumer millions and
> millions of dollars in munged heads and excess labor. and the thing is,
> they knew it would be that way too! the pinto fiasco, the exploder
> fiasco, red rear turn signals... frod management deserves a good hard
> kicking in the *****.

Wait a minute, "red rear turn signals" .... that's how they are supposed to
be. If God wanted them amber he would have given us better night vision. I
can remember when anything other than red in the rear was illegal. OOOps
...showing my age again.

 

"Tony Hwang" <dragon40@shaw.ca> wrote in message
news:5n00l.5769$R43.2829@newsfe08.iad...
> Forrest wrote:
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:Xym%k.10278$hx5.740@fe12.news.easynews.com...
>>> On Sun, 07 Dec 2008 16:15:30 -0700, Tony Hwang wrote:
>>>
>>>> Anon wrote:
>>>>> "Tony Hwang" <dragon40@shaw.ca> wrote in message
>>>>> news:i_X_k.12467$ED.7167@newsfe22.iad...
>>>>>> Anon wrote:
>>>>>>> Thanks to everyone that provided information and links.
>>>>>>>
>>>>>>> It really sucks that I'll have to spend $800-$1000 on my 2001 Honda
>>>>>>> V6. The car only has 24000 miles on it but is 7 years old. That
>>>>>>> almost makes me want to trade it in for a new car, one that doesn't
>>>>>>> use a belt that cost mega bucks to change.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> Hi,
>>>>>> You have to see that belt change is time consuming and also it is
>>>>>> good
>>>>>> time to to the water pump while at it. Belt itself does not cost
>>>>>> much.
>>>>>> Some cars have timing chain.
>>>>> If Honda is going to use a part that must be changed as part of the
>>>>> routine eminence schedule, it should be designed so it is easy to
>>>>> change. I consider it poor design.
>>>>>
>>>>>
>>>> Hmmm,
>>>> Designing something involves many factors. It is not as simple as you
>>>> might think. What is your definition of poor design? If you don't like
>>>> to spend some $$ at 100K miles or so, is it poor design? I think not.
>>> i think frod's desire to save a few cents by not having a compression
>>> washer on their spark plugs is one of the most fundamentally retarded
>>> design decisions of the 20th century. it's cost the consumer millions
>>> and
>>> millions of dollars in munged heads and excess labor. and the thing is,
>>> they knew it would be that way too! the pinto fiasco, the exploder
>>> fiasco, red rear turn signals... frod management deserves a good hard
>>> kicking in the *****.
>>
>> Wait a minute, "red rear turn signals" .... that's how they are supposed
>> to be. If God wanted them amber he would have given us better night
>> vision. I can remember when anything other than red in the rear was
>> illegal. OOOps ..showing my age again.
> Hi,
> Amber being in the middle of visible light spectrum, it is most visible to
> human eyes.

Actually, I think the point isn't weather or not you can see amber or red,
but which one destroys you ability to see anything else after having it
flash in your eyes while behind it. I really hate those vans with the huge
ambers mounted about two thirds the way up the back. A few seconds behind
one of those at night, is like staring at the sun and then walking into a
darkened movie theatre and trying to find a seat.

 

"Dillon Pyron" <invaliddmpyron@austin.rr.com> wrote in message
news:i2dtj49udshk20kkgkvguvkuctc50it2kb@4ax.com...
> Thus spake "L Alpert" <alpertl@xxgmail.com> :
>
>>
>>"Anon" <anonnospam@yahoo.net> wrote in message
>>news:OqOdnawJ9P6blabUnZ2dnUVZ_gqdnZ2d@giganews.c om...
>>>I have 2 Honda Accords, a 2001 V6 and a 2002 4 cyl. If the timing
>>>belt breaks, will it cause extensive engine damage?
>>>
>>> The manual on the V6 is unclear when to change the belt it says to
>>> change it at 60,000 miles if you drive in very hot or cold
>>> conditions. I do not have a manual for the 4 cyl, it was a used
>>> car.
>>> It has 94,000 on it now and runs perfectly.
>>>
>>>
>>>
>>
>>I believe the recommended change period is 105K miles or 7 years
>>under
>>normal conditions. My own interpretation of very hot has always been
>>desert type conditions (Death Valley, Sahara), very cold would be
>>similar to the northern Midwest areas and Canada/Alaska for the 60k
>>change.
>
> Not really. This year we (Austin, TX) had consistent highs of 100
> or
> more. And it's supposed to hit the low 30s/ high 20s tonight (it's
> 70
> something at noon).

Wide range here as well, but the extremes at both ends are limited in
time. I would think extended exposure to the extremes would be a
worst case scenario. I always use the change interval listed for
"normal" conditions, and it hasn't failed me yet (knock on wood).

>
>>
>>The key is not just the belt itself, but the internal cords/fibers
>>that do not allow the belt to stretch, which are usually made from
>>Kevlar/Twaron (both are aramid type high tensile fibers). I'm not
>>sure if the base OEM Honda belts are rubber, HSN or carbon fiber
>>type
>>(I would suspect that they may be the one of the latter two, as at
>>some point in the 90's they increased the recommended belt change
>>interval by a fairly large amount).
>>
>>Here are a couple of articles you may want to read....especially the
>>thermal properties of the Kevlar and interference engines.
>>
>>http://en.wikipedia.org/wiki/Timing_belt
>>http://en.wikipedia.org/wiki/Kevlar
>>
>>The potential damage from a broken belt is quite extensive, and you
>>may or may not see any symptoms.
>
> I think the phrase "complete engine rebuild" sums it up nicely
> (badly?)

Yep, I guess there is no way to soften the blow....I probably should
have said failure is usually catastophic....!

>
> Kevlar is wonderful in both tension and compression. But once a
> construction like a belt (or body armor) starts to fail, there's a
> cascade effect.

Try standing next to a 3 1/2" plasticating extruder with a 60 HP drive
running at 1750 RPM applying untold amounts of tourque through a huge
gearbox when one of those belts fail and gets tangled in the drive
sheave and rattles around for awhile......(usually a belt that is 10ft
or more in length by about 6" wide)....it can take years off of ones
life.

>
>>
>>
>>
> --
> - dillon I am not invalid
>
> When you wish upon a falling star, your dreams come true.
> Unless it's really a meteorite hurtling to the Earth which
> will destroy all life. Then you're pretty much hosed no
> matter what you wish for. Unless it's death by meteor.
>
>