Page 1 of 2
Timing chain
Posted: Tue May 15, 2012 9:01 am
by Bit of Both
Hi
I am busy restoring a 1960 Morris Minor. On the clock it has 55600 miles. The engine still runs well and a compression test showed it was still in good order. My question is whether to change the timing chain or not? How do one determine when to change it?
Thanks
Re: Timing chain
Posted: Tue May 15, 2012 9:26 am
by bmcecosse
Yes - change it and fit new rubber 'tensioner' rings, maybe also a new crankshaft sprocket - since it does twice the work of the cam sprocket! And of course a new seal in the timing cover.
Re: Timing chain
Posted: Tue May 15, 2012 10:08 am
by chickenjohn
Surely you only need to change the chain when it gets very worn and noisy???
It is extremely rare for a chain on an A series engine to fail. It is not a consumable item like a can belt.
Re: Timing chain
Posted: Tue May 15, 2012 10:43 am
by PSL184
Difficult one to call.... It's less than £20 for all the parts required and a half hour job, so on that basis, why wouldn't you? On the other hand, apart from noise, they rarely give any issues. The noise is due to the useless tensioning system employed which will become noisy again in a very short space of time anyway, unless you fit a proper tensioner from a Mini engine.
Re: Timing chain
Posted: Tue May 15, 2012 1:53 pm
by chrisd87
Little point in changing it, unless it's become noisy. Even then, it's very unlikely to let go - to my knowledge there's only one report of it happening on this board. In the incredibly small offchance that it did, the engine is of the non-interference type, so all that would happen is you'd grind to a halt. Valves would not hit pistons, etc.
Re: Timing chain
Posted: Tue May 15, 2012 5:36 pm
by MarkyB
a half hour job
With the engine on the bench maybe, I doubt it could be done with the engine in the car so fast.
I wonder what the "book" time for the job was.
Re: Timing chain
Posted: Tue May 15, 2012 6:54 pm
by PSL184
I doubled the time it took Roy to do one roadside in his best Sunday clothes

Re: Timing chain
Posted: Tue May 15, 2012 7:11 pm
by MMaurice52
The timing chain is 52 years old, replace it!
Timing chains DO wear out (stretch). A worn T chain can cause a cam to crank timing to be "out" by 10 degrees cuased by stretch. It's such a low powered engine, why allow those valves to open and close out of time?
Marc
Re: Timing chain
Posted: Tue May 15, 2012 7:15 pm
by PSL184
MMaurice52 wrote:The timing chain is 52 years old
Might not be - Might have been replaced a week before the previous owner sold the car

Re: Timing chain
Posted: Tue May 15, 2012 7:19 pm
by bmcecosse
The only information we have is that the car has done 55k miles...... And the OP is asking if the chain should be changed, so I rather assumed it could be heard rattling.. YES - fit a new one !! And yes - the Mini tensioner etc is much better - but also not inexpensive. So for most purposes - a new chain + rings + crank sprocket will do the job nicely.
Re: Timing chain
Posted: Wed May 16, 2012 7:14 am
by Bit of Both
Hi
Thank you for all the replies. I only heard the engine run for some hour and to be honest it was the first time that I have ever heard a Morris engine run. I would therefore not know whether it is noisy or not. As I am currently in the restoration phase, where the car is totally stripped and the paint is now being stripped, I thought that I might consider changing the chain if necessary as the radiator etc. is out of the way.
Re: Timing chain
Posted: Sat May 19, 2012 12:33 pm
by mike1864
Only last week MMOC's Tech Advisor told me the duplex chain was worth going for (complete with sprockets and two countersunk screws) especially if the engine's stripped down anyway.
Re: Timing chain
Posted: Sat May 19, 2012 6:37 pm
by bmcecosse
The duplex chain is NOT worth going for

It's for high lift cams and/or extra strong valve springs. The best way forward by far is to fit the Mini tensioner system. That's why MG/Rover did it! It IS quiet and stays quiet and doesn't cost a fortune. But a simple new chain + rubber rings + crank sprocket (it's a mistake to penny pinch by not changing that wee sprocket) will be good for many thousands of miles happy motoring on a standard engine.
Re: Timing chain
Posted: Sat May 19, 2012 6:51 pm
by MarkyB
For my money the duplex chain is a good upgrade, very easy to fit and extends the chain life far more than double as one might expect.
Instead of being over stressed like the simplex chain it's a bit under stressed and retains the original look.
Re: Timing chain
Posted: Sat May 19, 2012 6:53 pm
by bmcecosse
But it will rattle at idle, which the Mini system doesn't.... My current long suffering engine has it - and it rattles.

Re: Timing chain
Posted: Sat May 19, 2012 7:23 pm
by chickenjohn
The other concern I would have over changing the chain for the sake of it is the dubious quality of many modern parts! Are repro timing chains as good as the original 1960's items??
Re: Timing chain
Posted: Sat May 19, 2012 7:43 pm
by MarkyB
Not much you can do about that except buy a named chain.
The original chain was clearly not up to the job as it's virtually a service item.
Re: Timing chain
Posted: Thu Aug 21, 2014 11:45 pm
by Callum97
Could any of you direct me to a site or dealer from whom I could buy a mini chain tensioner. Would I run this with a standard minor timing chain kit, or with a full mini timing chain kit? Thanks, Callum
Re: Timing chain
Posted: Fri Aug 22, 2014 6:57 am
by philthehill
The kit of parts you require to fit the tensioner is available from MINI SPARES (Pt No: MSSK051). It contains all the parts you will need as regards the chain.
You will also need to find a suitable timing chain cover (Pt No: CAM4641 or CAM4904) to accommodate the tensioner.
If you can find a good S/H one so much the better. They are available new at £80 inc VAT.
Currently 4 on 'e' bay ranging from £10 - £20. Listed under 'Mini timing chain cover'.
Re: Timing chain
Posted: Fri Aug 22, 2014 10:07 am
by bmcecosse
The cost of new covers is just terrifying! You can run the tensioner against a standard Minor chain/sprocket combo - but they are likely to be worn - so may as well fit all new.