OT: timing belts

From: Chad Fernandez <fernande_at_internet1.net>
Date: Sat Dec 25 17:24:53 2004

Gordon JC Pearce wrote:

> Well, that's just down to stupidity.

That's called an interference engine.

> A new timing belt costs a tenner
> at the most and even on an absolutely evil b*st*rd of an engine to work
> on (step forward, Citroen XM 2.5TD, not nearly as nice an engine as the
> CX 25DTR) it takes at worst a couple of hours to fit. I can do Volvo 2-
> and 3-series belts in about half-an-hour...

Do these engines sit transversely in a front wheel drive (fwd) car?
Most cars here are fwd, and have the engines positioned transversely. A
lot of times you will have to disconnect at least one of the engine
mounts and lift the engine up. Also, since it's bound to be an overhead
cam engine, the accessorys will have to come off.

> As to why we use timing belts, well... The problem with timing chain
> designs is that the chains wear and go slack.

I don't know too much about chains used with overhead cams, but on push
rod engines this doesn't happen until many miles are on the vehicle.

The only problem I've had with a chain, actually was the top timing
gear, not the chain itself. It was on my 69 Buick LeSabre. The top
gear was aluminum with nylon or plastic teeth. They stripped off, while
on the highway. This happened in 1995, so the car was about 26 years
old, with 100K miles on it. I thought the gear design was dumb, but I
assume it was done for sound or vibration purposes. I know GM may not
rank very high with the Europeans on the list, but it's one of my
favorite cars that I've owned.

I did have belt problems once on my 1982 Dodge with a 2.2L engine. I
got it wet in the snow, since I plowed into a snowbank, with the plastic
cover off. I had a heck of a time getting it back into position, after
it skipped. I didn't really know how to get the belt around the
tensioner, cam pulley, and crank pulley with out throwing the timing
off. I was probably sick and tired of working on the car, in the cold,
and ran out of patience.

Chad Fernandez
Michigan, USA
Received on Sat Dec 25 2004 - 17:24:53 GMT