[alfa] Chains versus things that snap without warning

["Tim Hancock" <timhancock@xxxxxxxxxxxxx>]

<Chains are good for about 70,000 miles before they should be replaced,
and on some cars, the belt life approaches that pretty favorably. In
those cases, using the belt is a good decision.>

Can't run with that one I'm afraid, there are innumerable 164TS whose chains
are still merrily thrashing around without any problems at 150,000 plus miles.
In a clinical world perhaps the owners should have religiously had their
engines overhauled at 90,000 (to pluck a distance out of the ether). The
record I have come across personally for an 8 valve TS engine having had no
work whatsoever (normal servicing aside) carried out on it is about 280,000
miles. Later TS engines with rubber bands are a load of old rubbish by
comparison and break with appalling regularity. Progress?...don't make me
laugh!

Just in case anyone suspects me of cynicism (One of the few things we Brits
are quite good at), My take on why belts came in is 1) They are cheap for car
manufacturers to build 2) They require regular replacement which makes
business for workshops 3) They break regularly with no warning which gives
workshops even more business..or means you have to buy a new car as the cost
of a rebuild is more than the value of the car (see Alfa 164 V6 and many
others). All other so called advantages are just marketing boys flim flam with
no substance.

A rubber/composite item working in an oil dominated dirt laden environment is
just plain crackers. Timing chains thrive on oil, and indeed operate with
plenty of clean oil flying around in a filtered environment. What is more, if
a timing chain or tensioner is getting to the end of the road for whatever
reason, it normally announces this by getting noiser/ rattlier and giving all
concerned plenty of notice. Timing belts are the masters of high speed engine
Hara Kiri with no warning. Which do you prefer? Timing chains do wear out
eventually, but they do not degrade in the same insidious silent way that the
belt does.

A few chain systems are poor designs. The Lada engine had an awful timing
chain system, but they rarely destroyed the engine no matter how rattly they
became. The Nissan Micra has a single row chain that does break...design
fault...its too weeny for the job.

The simple fact that belts require regular replacement introduces the further
risk of incompetent fitters, and if you think every timing belt is fitted
properly then you are kidding yourself. Some garages in the UK will not do MOT
tests on diesel engines unless there is documentary evidence of a recent belt
change. So many have failed on test resulting in writs flying about that the
Test centres have had enough. No manufacturer I know of has judged the
replacement interval of belts accurately. They simply don't have a clue how
long they last, hence most manufacturers have had to HALF the original
expected life in the light of the number of breakages in real time use. As far
as I am concerned their credibility is shot to pieces on this issue.

FWD/RWD? Anyone who watched John Handley (It might have been John Rhodes..or
it might have been both of them come to that!) drive a 1000cc Mini round the
OUTSIDE of Graham Hill in a 3.8 Litre Mk 2 Jag going round Tatts corner at
Aintree in 1962 does not need much convincing that there is perhaps something
in this FWD thing. You might not like FWD, but that is a different matter. In
engineering terms it works, and in general provides a safer driving experience
for day to day drivers, reducing the risks of being put in an oversteer
situation, a situation which many drivers could not cope with...my mother
in-law being a prime example!

End of rant

Tim Hancock   Boston UK

164TS
164Super
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