Sounds tappety...

[Alex'n'Ane]

As the title suggests really, at tickover especially, the engine sounds kinda tappety.. However I have re set the tappets, they weren't bad to start with, and are now at 12thou inlet and 15thou exhaust. However this hasn't cured the issue. Its definately engine as disconnecting the fan belt temporarily makes no difference. Any suggestions as to what else it could be?

[chrisryder]

try 12 thou on both?

failing that... timing chain?

has it suddenly got loud, or has it been progressive?

[Alex'n'Ane]

try 12 thou on both?

failing that... timing chain?

has it suddenly got loud, or has it been progressive?

They were pretty much at 12thou on both already before adjustment..
Iirc, timing chain is more of a kinda rattly noise, and a new one was fitted about 3k miles ago apparently.
Its never been great since fitting the engine a few weeks ago, but seems to have got slightly worse.

[chrisryder]

Hmmm... wear in the rocker shaft? Worn cam followers?

[chickenjohn]

Set to 12 thou on both exhaust and inlet. Why 15 thou?? That will make the engine sound rattly. And possibly take the edge off the performance too as the exhaust valves will be open for a slightly shorter time.

But if still rattly then suspect timing chain.

[bmcecosse]

15 exhaust is essential if you want the exhaust valves to last....... cj knows that full well.... .... The noise could well be worn rocker shaft (as mentioned above) - easily checked - just pull each rocker off to the side and feel for a step. Would be worth trying another set of rockers if you have them..........

[Alex'n'Ane]

Because I have read on here a few times to set them to 15thou to allow for the extra burn temperature due to the unleaded fuel, especially if doing high motorway milage (I do around 500miles a week.. mostly motorway or 60ish.) They were all at pretty much 12thou already, its only the exhaust I actually had to adjust, and was equally noisy.

[bmcecosse]

Exactly....MG Rover changed the spec way back.

[Alex'n'Ane]

Would be worth trying another set of rockers if you have them..........

Would the 1275 rockers I got off you fit straight on? Or would you advise on just fitting another set off a 1098?

[bmcecosse]

The 1275 are fine for a more or less standard engine.

[moggiethouable]

The old wooden handled screwdriver to the ear test?

[JOWETTJAVELIN]

You need a listening stick to determine where precisely the noise is coming from, i.e. an old cricket stump or something. Hold one end to the engine where you suspect it's noisy and the other end to your ear 'ole - watch out for moving belts.

[JOWETTJAVELIN]

The old wooden handled screwdriver to the ear test?

You beat me to it!

[Alex'n'Ane]

I've already done the the stick listening test, and as I said before it pretty much confirmed it wasn't timing chain, and tappetey..

[chickenjohn]

15 exhaust is essential if you want the exhaust valves to last....... cj knows that full well.... .... The noise could well be worn rocker shaft (as mentioned above) - easily checked - just pull each rocker off to the side and feel for a step. Would be worth trying another set of rockers if you have them..........

Nonsense ! I've been running my minors for years at 12 thou (as it says in workshop and Rob Thomasson (MMOC tehcnical man) club manual) for years.

I did try the 15thou gap on the convertible last year, made the engine more rattly and took the edge off the performance.

Going to 15 thou could actually cause the exhaust valves and seats to be damaged sooner! the opposite of what is intended.

BMC, I think you are getting confused here because the way to tell vsr is happening is if the valve clearances reduce over time, but setting them wider in the first place will not cure this! Will just mask the problem (if it occurs) for a while.

[bmcecosse]

Oh well - if Rob Thomasson says so, it MUST be right. IIRC he's the chap that didn't know a clap hands Traveller was not right for a C reg......... And MG Rover must have got the gaps wrong too...... Oh dear - I wonder why they changed the spec ??? The idea of the increased gap is because the exhaust valves run hotter on unleaded fuel - and expand more - closing up the gap when running. I've explained that many a time in the past! If there is any recession taking place - it also gives a better safety margin - because if the gap ever goes to zero when running (but may still show a gap when checked) then that's the seat/valve damaged. Vizard actually suggests an increased gap may improve performance (by snapping the valve off the seat) - I seriously doubt that effect - but 3 thou extra gap (and it's much less when running anyway) will not make any significant difference to performance - either way.
But each to their own - set your gaps as you wish.
As for 'tappety' noise (the engine has no tappets) - just think of it as the clickety whirr of a well oiled machine.........

[MarkyB]

Is the oil feed to the rockers working OK?
I trust there is enough oil in the sump, has it got thinned out by the car running rich or with a lot of choke maybe?
If it feels thin between your fingers and smells of petrol, change it!

[les]

I've had a clicking noise coming from the distributor drive/assembly in the past but never been able to pin-point it, strangely it's intermittent.

[katy]

the engine has no tappets

Huh? Then what do you call the pieces between the camshaft and the push rod?
BMC called them tappets.

[bmcecosse]

Cam followers..... The side valve engine had true 'tappets' - with the valve gap adjustment built in to them. See Item 66 etc http://www.moss-europe.co.uk/Shop/ViewP ... exID=17070