why use timing belt?

Lowest cost/highest profit is what drives corporations. It's cheaper
to use a belt than a chain, it will last beyond the warranty period,
and most (not all) people who buy new cars will trade it in for
another new car before the timing belt becomes an issue. People who
buy used cars are used to (and should expect to) buying trouble in a
proportionate amount to the mileage - if I buy a used car with 75K
miles on it I expect some things need fixing, if I buy a car with 125K
miles on it I also buy a 6-pack of duct tape. I've had cars where the
engine lasts longer than the body, so when it looks that bad, who
would want to drive it?

I had a timing belt break on a Dodge Caravon/3.0L 6cyl Mitsu engine.
Two incredibly ironic twists - first, it happened while I was driving
to work, a light mist in the air, and I was thinking how nice and
smooth the engine was running when it suddenly just stopped running.
The second irony - I didn't want to do the repair myself, so I had a
shop do it. I had just gotten a state tax refund check 2 days earlier.
The repair cost exactly what the refund check was to the dollar (not
the pennies). I don' remember the exact numbers now, but something
like refund check $468.86, repair cost $468.12. Easy come, easy go!

Currently rebuilding a 1993 Plymouth Sundance Duster with the same
engine, a Mitsu 3.0L V6. What a cool and fun little car!

 

Yes, chains typically last longer. I had a 1964 Plymouth with a 273 V8
that went 200,000 miles on it's original chain.

During that time, however, some manufacturers used nylon-toothed
camshaft gears. I had a friend with a Pontiac and other with an
Oldsmobile where the chain stripped the teeth on the camshaft gears
between 80,000 - 90,000 miles. At least they were not too hard to work
on back then.

-KM

 

My 1951 Studebaker had phenolic gears to drive the camshaft. In a lot
of ways that car was better than anything made since.

 

I had a Subaru with all metal gear-driven cam. But, alas, Subaru has
also gone the way of the "We're no worse (or better) than anybody else"
philosophy when it comes to design and major component longevity. I
guess it must be necessary to compete in today's marketplace.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

You made every bit of that up. You've never worked for an auto
manufacturer, or ever spoken to any person involved in that decision for any
car in real life. You've never taken a survey of used car buyer
expectations. You have literally no information about the correctness of
what you've posted, and no way to even begin to find out if it's correct.

I mention this because a thinking person would distinguish between
information you have and information you've made up. Most ordinary people
don't make that distinction.

 

Not sure what your point was, but it inadvertently supports what I was
talking about. That used car is probably due for a timing belt. A
savvy buyer will know about that and use it to wittle the price down to
pay for the timing belt/water pump job. The unwary buyer will buy it
thinking she's gotten a bargain, only to find out later that she has to
spend $700 right off the bat for that work, or find out in short order
the hard way that it needed to have that done and end up with expensive
engine damage (assuming it has an interference engine, which the
overwhelming majority of them these days do.

In either case, the value of the car will have been decreased that much
more *UNNECESSARILY* because of the use of timing belts. In any case,
again, the value of that car will have been decreased by it and there is
no question that statistically it will end up being junked earlier in
its life than necessary due to the cost-to-value thing. Point being
that you can help all considerations to the consumer by not using timing
belts - maintenance costs, end of life (go to the junk yard) point, cost
to the environment of replacing it with another car having to be
manufactured, and probably a few things I haven't thought of.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')