What does timing chain rattle sound like

[Stag About Town]

My only experience of timing chain rattle was many years ago when I had to change the chain on a mark one Consul. That noise was what I would describe as quite a hard knocking noise. Also the knock was intermittent rather than in tune with the engine. What do Stag chains sound like when stretched? Is it an unmistakable knock? I have a light tapping noise on tick over that is in time with the engine. Any ideas or comments? John

[NeilR]

Cam Follower maybe.

[ramjam2005]

Hi John, In my personal opinion the Stag engine has never been the quietest, even when in good fettle and a LIGHT rhythmic "tapping" noise isn't uncommon from the top. There are many Youtube videos to demonstrate this. But if more pronounced it could be one of the valve bucket shims (cam followers as per NeilR), more than rattly timing chains. You could try using a stethoscope to isolate it to a specific area - A nice long sturdy screwdriver placed in different spots whilst resting your ear against the handle is an old mechanics favoured method. ( My dear old dad shared this with me some 50 years back). Mind that spinning fan if at the front for timing chains !!

As always someone more knowledgeable of the internal workings will be along soon I'm sure. .. Ray

[Goldstar]

Cylinder 6 bucket I reckon

[022Dave]

Don’t rule out an exhaust leak; they can sound like ticking or tapping.

Dave

[jbuckl]

The small end aka piston pins & conrod bushes on cylinders 6&8 also get more wear than all the rest… as they receive more dirt being thrown up at them than the rest…. Due to engine inclination angle & crank rotation.

Not exclusively, but often, they produce the light noise possibly being mentioned here.

changing a small end bush is straightforward but involved.

Resizing the bush requires a sonnen honing machine or similar…. It cannot be achieved satisfactorily using hand tools….e.g. reaming.

imho a stag engine can be built to be beautifully smooth & quiet, with an orchestral exhaust note…. But it requires greater cost and effort than a standard budget rebuild.

One highly experienced stag engine builder only uses a complete set of remanufactured con-rods in their builds…. Highly recommend doing that.

Have also seen left hand heads where cam buckets touch the head on full lift, due to tolerances being exceeded….causing noise.

cam bucket wear is also a culprit as previously mentioned too.

usually tensioner extension is a good indicator of chain wear and can be seen via the oil filler and or removal of the right hand cam cover.

[Stag About Town]

Thanks for all your replies. I am probably suffering from an attack of Stag paranoia but out of interest is it easy to check and maybe correct any cam bucket issues? I did drop an endoscope down the oil filler hole after viewing other posts but I couldn't see much. My Stag has about 45K on the clock, believed genuine, but I have no evidence as to replacement of the chains or anything else major. John

[ramjam2005]

but out of interest is it easy to check and maybe correct any cam bucket issues?

Hi John , Never done the job myself but heard it can be a pain and time consuming. Whilst it sounds easy in it's simplest form, it's a case of checking that the gap between each of the cam lobes and the cam followers are within the specified tolerance then replacing the bucket shims accordingly, which come in various thicknesses, to get the correct gap.
Use the search facility on here to find some examples and guides. Not as simple as the good old fashioned adjustable rocker arms I'm afraid !
Ray

[Stag About Town]

Hi John , Never done the job myself but heard it can be a pain and time consuming. Whilst it sounds easy in it's simplest form, it's a case of checking that the gap between each of the cam lobes and the cam followers are within the specified tolerance then replacing the bucket shims accordingly, which come in various thicknesses, to get the correct gap.
Use the search facility on here to find some examples and guides. Not as simple as the good old fashioned adjustable rocker arms I'm afraid !
Ray

Thanks Ray. If that job needs doing I think I will employ an expert. John