Lotus Elan

Twincam Timing Chain Noise

PostPost by: Matt7c » Wed Mar 09, 2005 10:20 pm

Having recently started my TwinCam after 13 years, I notice that the timing chain is quite noisy. Never having heard a twink in top shape, I don't know how much noise is too much noise. Should I be able to here the chain at all?

The noise itself doesn't sound bad, there is no metal on metal scraping or anything, just the constant noise of chains running over sprockets. I haven't heard an engine make this noise since I had a Fiat in the late 80s...

Matt
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PostPost by: Elanman99 » Wed Mar 09, 2005 10:55 pm

Matt,

It sounds as if you might have yout chain too tight. I have found that the best way to set the belt tension is to turn the adjusting screw with the engine running. If the chain is slack it makes a rattling noise, too taught and it makes a 'zizzing' sound something like gears in mesh. With the engine running you will easily find the point where the sound changes. I just go slightly past the rattling point.

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PostPost by: mikefromengland » Wed Mar 09, 2005 11:28 pm

if the chain is too tight the eginin will sound a bit like a vaccuum cleaner.sereuosly.
if it is rattleling its too loose.if the adjuster is wound in too far already the chain will need replacing.also the slap pad could be worn out.if the chain is very loose the sound would be deafening.the twink should run quietly.the ajustment in the chain is about 13mm.
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PostPost by: Hamish Coutts » Thu Mar 10, 2005 1:28 pm

Matt,

A long shot - are you shure it's the timing chain that's making the noise? When I started my twink after a 2 year layoff it was the water pump bearing that was making a hell of a noise. A quick spin of the waterpump pulley when the fan belt is off should show if there is a problem there or not. The bearing should feel smooth and be silent.

:)

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PostPost by: Matt7c » Sun Mar 13, 2005 7:25 pm

Thanks for the tips, fellas. There might not be a problem after all - as I run it more and more, its getting quieter! Useage seems to be loosening it up - that and letting it run long enough to heat the oil. When I first got her going, the fan wasn't functioning and so I didn't want her to run too long and overheat. Now I have sorted the fan, I can run the engine a while and the whole thing is quietening down nicely. Had the PO down this weekend and he said it sounded OK to him, so it seems the issue is going away...
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