On Thu, 14 Aug 2014 17:41:48 -0800, "Guv Bob"
wrote:

"nestork" wrote in message ...

OK, I give up.

What is gained by designing interference into the engine?

Is it just that engines can rev faster and therefore produce more power
at high rpms?

It seems to me that if I had my druthers, I'd druther have a car with a
non-interference engine and make do with a bit less power.

The story I heard (no idea if true...) is that it makes for a smaller engine.

My question is.... if a broken timing belt can do this much damage (I had one break myself), why don't they use timing chains?
Timing belts are lighter, cheaper, and more efficient than chains -
and also can be quieter. Many companies are resorting to chains on
their newer engines. We'll see if they have solved the
lubrication/wear problems that made belts so attractive on overhead
cam engines where 3 1/3 feet of chain had a bad habit of stretching
and rattling (and when they used 2 chains, like the Mitsu/Chrysler 2.6
- over SIX FEET).chain guides and tensioners were constantly requiring
attention.