timing belt or timing chain?

Rev. Tom Wenndt wrote:

> To this day, most of the domestics still use a timing chain, and
> rarely does one ever think about them. A few of the DOHC engines
> (like the 3.2L and 3.5L in the Dodge Intrepids of the last dozen or
> so years) used a timing belt.

I'd say most domestic V-6 and V-8 engines have timing chains, but most
of the domestic I-4's, which by and large are based on foreign design,
use timing belts.

--
 >> Stay informed about: timing belt or timing chain? 

"Screwtape III" <gfy.RemoveThis@bkbusa.com> wrote in message
news:xn0eh8ihu1kfn8f000@news.individual.net...
> yat70458 wrote:
>
> > I was reading an earlier thread about when to change out the timing
> > belt.
> >
> > Please excuse my ignorance...I am not a Hyundai owner yet but am
> > seriously considering the Tucson or Sante Fe. I thought most new
> > cars nowadays used timing chains, which I heard can last forever.
> >
> > Thanks for your response.
> >
> > yat
>
> The Mazda 2.3 DOHC engine has a timing chain, which by itself is good.
> It also has something called "Variable Valve Timing", which sounds to
> me like a failure waiting to happen.
>

Not as much of an eminent failure as you might think. Variable Valve Timing
(in different forms) exists in a lot of engines these days. Most
manufacturers either have a form of VVT or are experimenting with it. Some
of the stuff that's being toyed with is quite radical for your basic
internal combustion engine. It's not inconceivable that the camshaft will
become a thing of the past, giving way to the ever-present computer, which
will monitor and adjust valve timing.

--

-Mike-
mmarlowREMOVE.RemoveThis@alltel.net
 >> Stay informed about: timing belt or timing chain? 

Although Gilmer (that's its real name!) timing belts seem to be a
rather new innovation, they've been used for many decades. That being
said, however, timing chains were generally used by most manufacturers
before the shift to Gilmer timing belts.

Most OHV engine designs used timing chains (most USA manufacturers) or
timing gears (many European manufacturers). Actually, timing gears are
the best, but can be costly to design and manufacture.

In most OHC designs, timing chains were historically used. For
example, the classic Jaguar DOHC inline 3.8L and 4.2L six used timing
chains, as well as most other European cars including the SAAB SOHC and
DOHC inline four. FIAT used Gilmer belts in their 124 series in the
'60s. Mercedes and Porsche used, and still use, timing chains.

Timing chains are more durable than the Gilmer belt. The generally
accepted design spec for replacement of the Gilmer belt is 50,000 to
100,000 miles. Hyundai specifies replacement of the belt at 60,000. On
the other hand, a timing chain - either simlex or duplex - can last
much, much longer. The primary problem with a timing chain design over
time and mileage is chain stretch. This natural wear is compensated by
a timing chain tensioner, either oil pressure or mechanically operated.

One of the primary reasons for the original shift from a timing chain
to the Gilmer belt is one of economics. Although the timing chain is
more durable than the Gilmer belt, it's generally much more expensive
to replace on an OHC engine than a belt. Not only is the timing chain
itself more expensive ($50 to $200), the replacement (labor) can be
very costly. In some OHC designs which use a timing chain, the engine
has to be pulled to effect the repair. Whereas the Gilmer timing belt
is inexpensive ($20 to $50) to purchase, and the replacement cost is
much less than a timing chain. NOTE: Although we Hyundai owners may
complain about this fact, it's nevertheless much less than a timing
chain replacement.

Timing chain replacement in the classic American OHV engine design is
also quite inexpensive, both in terms of parts cost and labor.
Although OHC engine designs are much more efficient, the efficiency
comes at a long-term maintenance cost increase over OHV designs.
 >> Stay informed about: timing belt or timing chain? 

Rev. Tom Wenndt wrote:

> To this day, most of the domestics still use a timing chain, and rarely does
> one ever think about them. A few of the DOHC engines (like the 3.2L and
> 3.5L in the Dodge Intrepids of the last dozen or so years) used a timing
> belt.
>
> Imports much more frequently have used a belt. It allows (supposedly) for
> smoother, quieter operation and better fuel economy for the set-up. But of
> course, any belt is a maintenance item, and since many of those engines are
> "interference" engines, meaning if the belt breaks, you bend or break some
> things in the engine (valves, etc.), you best not forget about it.
>
> Something to ponder when you are deciding which vehicle to buy. (All Santa
> Fe engines for sure would have timing belts).

My 2006 Sonata with the 2.4L engine has a timing chain, if the web site
is correct. I think the new 3.3L V-6 has a chain also, but I'm less
sure on that one.


Matt
 >> Stay informed about: timing belt or timing chain? 

Screwtape III wrote:

> yat70458 wrote:
>
>
>>I was reading an earlier thread about when to change out the timing
>>belt.
>>
>>Please excuse my ignorance...I am not a Hyundai owner yet but am
>>seriously considering the Tucson or Sante Fe. I thought most new
>>cars nowadays used timing chains, which I heard can last forever.
>>
>>Thanks for your response.
>>
>>yat
>
>
> The Mazda 2.3 DOHC engine has a timing chain, which by itself is good.
> It also has something called "Variable Valve Timing", which sounds to
> me like a failure waiting to happen.

So do the new Hyundai engines. Time will tell...

Matt
 >> Stay informed about: timing belt or timing chain? 

My first introduction to a timing belt was when the one on my mid-80s Escort
broke. It was painful!

--


"Rev. Tom Wenndt" <trwenndt.RemoveThis@grics.net> wrote in message
news:dqcde70tvp@enews3.newsguy.com...
> To this day, most of the domestics still use a timing chain, and rarely
> does
 >> Stay informed about: timing belt or timing chain? 

On Sun, 15 Jan 2006 14:01:22 GMT, Matt Whiting <whiting DeleteThis @epix.net>
wrote:

>Screwtape III wrote:
>
>> yat70458 wrote:
>>
>>
>>>I was reading an earlier thread about when to change out the timing
>>>belt.
>>>
>>>Please excuse my ignorance...I am not a Hyundai owner yet but am
>>>seriously considering the Tucson or Sante Fe. I thought most new
>>>cars nowadays used timing chains, which I heard can last forever.
>>>
>>>Thanks for your response.
>>>
>>>yat
>>
>>
>> The Mazda 2.3 DOHC engine has a timing chain, which by itself is good.
>> It also has something called "Variable Valve Timing", which sounds to
>> me like a failure waiting to happen.
>
>So do the new Hyundai engines. Time will tell...
>
>Matt

And I will add that I am very pleased with the results. My new
Alantra scoots much better than my Accent ever did. The VVT seems to
broaden the torque curve quite a bit.

nothermark
 >> Stay informed about: timing belt or timing chain? 

One of the reasons for the increased cost of using timing chains (beyond
the cost of the parts themselves) is that a timing chain must run in an
oil bath, which in the case of automotive engines, is generally the
sump. That means that it must also have an oil-tight cover over it.

Timing belts run dry and need nothing more than a cheap plastic cover to
keep out dust, dirt and moisture.
 >> Stay informed about: timing belt or timing chain? 

Don wrote:
> Although Gilmer (that's its real name!) timing belts seem to be a
> rather new innovation, they've been used for many decades. That being
> said, however, timing chains were generally used by most manufacturers
> before the shift to Gilmer timing belts.
>
> Most OHV engine designs used timing chains (most USA manufacturers) or
> timing gears (many European manufacturers). Actually, timing gears are
> the best, but can be costly to design and manufacture.
>
> In most OHC designs, timing chains were historically used. For
> example, the classic Jaguar DOHC inline 3.8L and 4.2L six used timing
> chains, as well as most other European cars including the SAAB SOHC and
> DOHC inline four. FIAT used Gilmer belts in their 124 series in the
> '60s. Mercedes and Porsche used, and still use, timing chains.
>
> Timing chains are more durable than the Gilmer belt. The generally
> accepted design spec for replacement of the Gilmer belt is 50,000 to
> 100,000 miles. Hyundai specifies replacement of the belt at 60,000. On
> the other hand, a timing chain - either simlex or duplex - can last
> much, much longer. The primary problem with a timing chain design over
> time and mileage is chain stretch. This natural wear is compensated by
> a timing chain tensioner, either oil pressure or mechanically operated.
>
> One of the primary reasons for the original shift from a timing chain
> to the Gilmer belt is one of economics. Although the timing chain is
> more durable than the Gilmer belt, it's generally much more expensive
> to replace on an OHC engine than a belt. Not only is the timing chain
> itself more expensive ($50 to $200), the replacement (labor) can be
> very costly. In some OHC designs which use a timing chain, the engine
> has to be pulled to effect the repair. Whereas the Gilmer timing belt
> is inexpensive ($20 to $50) to purchase, and the replacement cost is
> much less than a timing chain. NOTE: Although we Hyundai owners may
> complain about this fact, it's nevertheless much less than a timing
> chain replacement.
>
> Timing chain replacement in the classic American OHV engine design is
> also quite inexpensive, both in terms of parts cost and labor.
> Although OHC engine designs are much more efficient, the efficiency
> comes at a long-term maintenance cost increase over OHV designs.
>
And then there is my Fort Taurus SHO. Timing belt placement is such
that one the case is opened it is better to replace water pump, front
seal, Crank sensor and a host of other stuff as the labor charge is
monumental. Lucky it's a non-interference engine.
 >> Stay informed about: timing belt or timing chain? 

Thanks for all the responses. All the information has been helpful. I get
the opinion that the difference in having a timing belt over a timing chain
is that the belt is less expensive...for the part as well as the
installation. Having the belt replaced at 60k miles should be considered
routine long term maintenance.


"yat70458" <ejleche DeleteThis @bellsouth.net> wrote in message
news:DJhyf.13$Tc.11@bignews7.bellsouth.net...
> I was reading an earlier thread about when to change out the timing belt.
>
> Please excuse my ignorance...I am not a Hyundai owner yet but am seriously
> considering the Tucson or Sante Fe. I thought most new cars nowadays used
> timing chains, which I heard can last forever.
>
> Thanks for your response.
>
> yat
>
>
 >> Stay informed about: timing belt or timing chain? 

Don wrote: "And then there is my Fort Taurus SHO. Timing belt placement is
such that one the case is opened it is better to replace water pump, front
seal, Crank sensor and a host of other stuff as the labor charge is
monumental. Lucky it's a non-interference engine."......

Actually, that is true with many vehicles, particularly the water pump.
That is often used as the tensioner for the belt, making it something
replaceable when you replace the belt with virtually no additional labor.

But those who said timing belts are cheap need to price out some of them.
The Kia Sedona minivan's does not come cheaper than $110 (that I can find).
That is just the part - with labor, I have one quote for $450, and I have a
hunch it won't get much cheaper. That is not chump change to me.

Green Valley Giant
 >> Stay informed about: timing belt or timing chain? 

Rev. Tom Wenndt wrote: "The Kia Sedona minivan's does not come cheaper
than $110."

The best price I've found on the Sedona timing belt is $94. Thus, it's
more expensive than your usual timing belt parts cost. I imagine this
is due to the V6 design, and most cost references to belts are those
used in Inline 4 cylinders.

Although $450 is a significant amount of money, it's still cheaper than
some timing chain replacements which require the engine to be pulled
from the vehicle. This is most often the case in some of the European
vehicles.
 >> Stay informed about: timing belt or timing chain? 

Rev. Tom Wenndt wrote:
> Don wrote: "And then there is my Fort Taurus SHO. Timing belt placement is
> such that one the case is opened it is better to replace water pump, front
> seal, Crank sensor and a host of other stuff as the labor charge is
> monumental. Lucky it's a non-interference engine."......
>
> Actually, that is true with many vehicles, particularly the water pump.
> That is often used as the tensioner for the belt, making it something
> replaceable when you replace the belt with virtually no additional labor.
>
> But those who said timing belts are cheap need to price out some of them.
> The Kia Sedona minivan's does not come cheaper than $110 (that I can find).
> That is just the part - with labor, I have one quote for $450, and I have a
> hunch it won't get much cheaper. That is not chump change to me.
>
> Green Valley Giant

I was quoted $225 Canadian at the Oakville Hyundai dealership?

Chris
 >> Stay informed about: timing belt or timing chain?