A couple of timing chain questions please (Vit Mk1 2 Litre)

[daverclasper]

Hi.

Unknown history of engine in mine , though guessing standard. Don't know if has been rebuilt or had hard use. 120,000 on clock.

In normal use is there much chance of it breaking/stretching and do valves interfere with pistons.

Any help great, thanks.

Dave  

[Pete Lewis]

Chains dont stretch   they do wear at the chain rollers and that makes it a little longer as the wear takes place and distance between the links .... grows a little 

What it does is make the valve timing a   bit late as the operating  length changes,    

Well worth doing at your mileage , it will brighten the engine and reduce noise at the front

Read up about valve timing the cam gear has holes to give adjustment in 1/4 tooth increments by swapping bolt holes and turning the gear over,   it needs to be right 

Pete

[Nick Jones]

Valves can't hit pistons - unless it's a domed piston engine - in which case they can....... but there shouldn't be a domed piston engine in a Vitesse.

Watch out for chain (and tensioner) quality if taking the plunge as the combination of a nasty, sharp edged chain and tensioner made from old bean cans will make you wish you'd left well alone.  If the engine is running well without chain noise, pinking of running-on, probably best left alone.

Nick

[Algy]

I would add, if you are going to change the timing chain, replace the sprockets and adjuster at the same time and if you plan on a cam change or doing a lot of miles use a duplex chain.

Best way to find out if you are really worried is to take the timing cover off and check the sideways play in the chain (across the link not the way it is bends) and for sharp edges on the sprocket teeth and groves in the tensioner. But if you have gone to all that effort, in the car, it is not much more to replace and sleep sound.

Driving the car hard is not much of a factor for chain wear, milage is and normally shows in other areas, such as smoke from exhaust. If it is sound, I would go with Nick and enjoy driving it until you start to loose performance. Give it regular oil and filter changes.

[JohnD]

The ST WSM check is that there should be less than 10mm of slack between the two sprockets.   Lay a straight-edge against the chain and pull it towards the inside..

Chain 'stretch' (yes, Pete, it's mainly wear!) gauges are popular for bikes, motor and push.     They are either notched rules, that are mostly too long  for our tuiming chain, or tensioning, like lthis one, that measures the %age of 'stretch'.    As it says, more than 1% needs replacement.

John

[daverclasper]

Hi. Thanks a lot for the input.

It is quiet and car runs ok, so will let sleeping dogs lie.

Was more concerned about it breaking and trashing valves, as have read Triumph engines can do this, though I have always thought with any chain it wasn't a particular issue.

Cheers, Dave 

[Nick Jones]

Never heard of an OHV Triumph doing this.  As mentioned earlier, only the domed piston 2L versions have any possibility of interference.  The OHC ones (1850 & Sprint Dolly, TR7 & Stag - that's a different matter, though they are very reliable compared to certain recent BMW and VAG offerings!  Vorsprung durch technik........ or not.

Nick