On Mon, 6 Nov 2017 04:49:14 +0000 (UTC), RS Wood >
wrote:

>Steve W. wrote:
>
>> Chains don't mean a lot when they drop them down to bicycle sizes with
>> small pins. Things stretch like cheap rope.
>
>I think the only reason manufactures went to belts is to increase their
>profits, so I wonder if there is any value to a belt AFTER you look at the
>tradoffs.

No, chains stretch - belts don't. Belt timing is more accurate and
consistant. Belts are more efficient at transmitting power.
Belts are much easier and cheaper to replace
>
>The real question for a repair group would be the main factors:
>1. Reliability of chain versus belt
It can be pretty much a wash
>2. Damage potential of chain versus belt
When a chain goes bad, it does more damage than a belt
>3. Repair hassle of chain versus belt
A lot more hassle when a chain brakes.
>
>Let's ignore the marketing bull**** (e.g., lighter, quieter, etc.) for this
>thread to concentrate on the reliability and repair-related issues.
>
>As I already noted, I *wish* I had replaced a timing chain in my life, but
>just like I've never owned a FWD vehicle (and I lived in a "snow state" for
>decades), I have never had a belt car and I've never had a chain break on
>me.
>
>So I have no experience.
>But....
>
>I posit that:
>1. The chain is *far* more reliable than the belt
Not necessarilly true
>2. Both can ruin an interference engine if they break
Correct - and the cain causes more damage and is more expensive to
repair
>3. Repair hassle is probably about the same
Nope - an order of magnitude worse with a chain
>
>The question is how long is the typical MTBF for a belt versus a chain?

Belts - 60- 100 thousand Km in the past - some last a lot longer but
don't take the chance on an interference engine. an hour or 2 to
change it, and mabee 50 bucks for the belt vs 6 hours plus the cost
of tensioners and sprockets and chain (often over $200) for the chain
- which SHOULD last longer than 2 or 3 belts - but the average car
will only have the belt changed 3 times in it's lifetime