in david vizards book on 'tuning the a series' he says that there is a timing belt upgrade made by caltrac , now no matter how good the timing chain is, it always gives off some noise, and i have a little ocd thing about anything other than exhaust noise, so i was wondering if anyone has fitted this , or made a similar type of kit from a different engine or something ?
cheers wvg
Avoid avoid avoid - it's a dreadful thing....... Best upgrade is to the later Mini single chain with spring loaded rubber tensioner...... or if using high lift cam with strong springs - go the Duplex route.
I remember a timing belt kit being marketed in the early 1980s. Not sure if it's the same one, but at the time, the maintenance interval was replace at 18,000 miles. I asked them if they were serious about changing it once a year As above, stick with the chain.
i've never heard one without the rattle, does it actually make the difference ?.. it really bugs me, being used to Rolls Royce kinda noise levels n what not .I understand that a series aren't that oil tight when it comes to crank seals, thus making a belt a terrible idea, but , it would hold timing better and possibly be slightly more responsive..possibly ....
The A-Series duplex chain is very quiet. Very simple swap, just need to countersink the bottom 2 holes in the front plate and use countersink headed screws to give the additional clearance for the wider chain. Other than that I would always use the later timing cover with the 'proper' lip oil seal, and not the earlier felt seal.
The timing belt kit is still available from the various MIni tuning specialists, and is silent as well as providing slightly smoother running. BUT from bitter experience does not like a hint of oil at all! I replaced the Kent 276 cam with one from a different, but very well-known supplier, as theirs has cross-drilled lobes and journals, but they had not tightened the grub screw at the front of the cam that blocks off the oilway. 3,000 miles later the belt stripped a number of teeth, bent all 8 valves and pushrods, and left us stranded in France!
Norton Heritage Insurance were superb and had a breakdown truck to us in less than a hour, then hire cars both sides of the Channel - superb service.
On stripping the engine after the car's repatriation back to the UK there was a smear of oil on the timing pulleys and the belt. On reassembly, I have reverted to a duplex chain and vernier adjustment kit. Once bitten etc!!
My son has just bought a cam from the same supplier for his MGB GT, and it comes with a big note to say that the grub screw is not fitted and is in the bag with the woodruff key, and must be Loctited in before fitting the cam - at least they have learnt from their mistakes!
Last edited by IslipMinor on Tue Aug 07, 2012 10:57 pm, edited 1 time in total.
Duplex is not necessarily rattle free - sure - it's newer and much stronger, but over time it will still wear and start to rattle. But if you only do low miles - that could be 100 years away.... MG Rover developed the tensioner kit for a good reason - and it works....