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Hello All,

My only experience of "pinking or pinging" is what I've read on this forum in the past.  A forum member once likened the sound to marble(s) rattling in a jar, and that's exactly the sound I'm getting right now.

The only recent change I've made is a fitting a Phoenix extractor manifold. I should mention it's a TR6 Pi with a fast road camshaft distributor and metering unit tuned to suit the camshaft. Regardless of correctly aligned timing marks the engine previously ran perfectly at 15 deg BTDC.

Now it's all back together and I've just been re-balancing the throttle butterflies (had to do this after fitting new ex manifold), this pinking sound is there and very audible, I've tried adjusting the timing this way & that, but the sound is still there.

Has anyone got any ideas what the cause could be...…..a fresh 20lt of petrol was added to the tank earlier today before I started the tuning and throttle balancing process.

Regards,

Richard.

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Richard

it could be a fuelling issue (and/or timing) it could be a bit lean

it could be a bit advanced timing wise. 

Could be both. 

Tends to sound worse with a stainless extractor system as well. 

(Also make sure all the inlet and exhaust gaskets are properly sealed on the ports)

 

H

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Thanks Hamish,

I've just done a web search and found exactly as you refer to regarding fuel. The 20lt I added to the tank earlier is BP Ultimate bought from the same garage I use mostly. Makes sense it sounding worse with the stainless manifold. The manifold gasket is sealed properly, I'm confident of that. I really don't want to run for too long for fear of damage, I certainly don't want to put it under any load.

I'll get back to it tomorrow after work.

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Hi Richard,

     if all the obvious things are done then why not retard the ignition back to 10'BTDC and see what happens.

If the engine (bores or valve guides) are badly worn then excess engine oil into the combustion chambers can lower the RON.

 

Roger

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Thanks Roger,

Your suggestion is where I'll be going tomorrow, though it seems strange it's only started pinking after fitting the new exhaust manifold. The engine is in top condition, only covered around 2000 miles since rebuild. I'm also wondering if by mistake I filled my Jerry can with regular unleaded? May buy some more fuel tomorrow.

Thanks again.

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4 minutes ago, Richard71 said:

Who's Dr Bingley and what is it he would have done pray tell?

Hi Richard,

           he was a polymath and a prototypical British  inventor. Not that he was mad in any way but had a certain focus on things that would worry a Bull dog.

When leaded petrol was about to be removed he set about cooking  a few formulations and started Project Green.

His TR6 was the running test bed and had all sorts of pumps and contraptions to make it go just as TRiumph wanted.

Sadly he died a few years back.

 

Roger

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15 minutes ago, RogerH said:

Hi Richard,

           he was a polymath and a prototypical British  inventor. Not that he was mad in any way but had a certain focus on things that would worry a Bull dog.

When leaded petrol was about to be removed he set about cooking  a few formulations and started Project Green.

His TR6 was the running test bed and had all sorts of pumps and contraptions to make it go just as TRiumph wanted.

Sadly he died a few years back.

 

Roger

Roger, - not for me to ever pick you up but....... Suspect he made it go just that bit better than “TRiumph wanted”?!

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2 minutes ago, Tony_C said:

Roger, - not for me to ever pick you up but....... Suspect he made it go just that bit better than “TRiumph wanted”?!

I was being polite. Dr.Michael was able to brew some stunning stuff.

 

Roger

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Richard, do I understand correctly that you’re hearing pinking when the engine is idling?  Normally you’d hear it when the engine is under load in a high gear but it’s not clear from your post whether you were under way or not. 

If it’s at idle and nothing else has changed then I’d venture to say that what you’re hearing is a noisy tubular exhaust.  

If it’s evident under load then check that the TDC mark on the crank pulley really is at TDC, they do slip. Then retime to 12 deg btdc and see what happens. 

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17 minutes ago, peejay4A said:

Richard, do I understand correctly that you’re hearing pinking when the engine is idling?  Normally you’d hear it when the engine is under load in a high gear but it’s not clear from your post whether you were under way or not. 

If it’s at idle and nothing else has changed then I’d venture to say that what you’re hearing is a noisy tubular exhaust.  

If it’s evident under load then check that the TDC mark on the crank pulley really is at TDC, they do slip. Then retime to 12 deg btdc and see what happens. 

Yeah, that's right Peejay, I've only ran the engine at various idle speeds since fitting the new manifold, haven't had time yet to take it for a run and as said in my original post, I'm not in slightest bit familiar with pinking. I had the engine tuned a few months ago by an ex Triumph mechanic, he remarked on it's lack of pinking and complimented on how strong & smooth the engine was.

You may well be spot on with the noisy manifold, that hadn't occurred to me. But I'll need the confirmation of an experienced pair of ears.

Richard.

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Sounds like a manifold leak.......very common with tubular manifolds not mating properly with the head or even touch the ribs on the side of the block meaning a gas leak clicking on the lower side of the manifold. 

Iain

Edited by iain
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I fitted a Phoenix 4 branch to my '3 & I got a strange "chirping" noise.  it turned out to be two of the down pipes so close to each other that under slight vibration they would chatter against each other. The cure was to jam (hammer) a thin wedge of steel between the two pipes to force them slightly further apart.

Bob.

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Interesting comments, primary pipes 4 & 5 are actually in contact with eachother. I noticed this before fitting, called TR Shop & Phoenix exhausts, both said it won't be an issue, seem it could be.

I checked the manifold flange with a straight edge before fitting and all looked good, no reason to suspect poor mating. No other contact with the engine block etc.

I'll close the bonnet and take it for a good blast as soon as I can.

Richard.

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If you are still concerned after your run, is it possible to take a short video with sound and post it on YouTube or similar for others to listen for a diagnosis?

TBH I'm not sure if this is realistic, as I've never done it...

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Richard,

I have a stainless extractor on  TR4 and had a strange tinkling noise (also someone else on here had the same issue) which actually came from within the exhaust rather than the engine.Listen carefully with a length of tube to determine exact location.The noise was like having a small shillie/pebble rattling in the base of the downpipes.The noise was there only when the engine was warming up and eventually went altogether with no further intervention.

John

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Update...…..

I've had a neighbour mechanic have a quick listen and it's not pinking, that's been a red herring. There's always been a slight ticking sound from the engine, I think that sound has been changed & amplified by the stainless extractor manifold.

I've checked all the valve lift heights and they're within spec, carried out a compression test and all is good there also, nothing  conclusive. The sound does seem to come from cyl #2 and I recall a post I entered on the forum back in January    .

I'll borrow a bore scope from work next week and see if there's something going on within the cylinders, particularly #2.

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If you have an alloy rocker cover and roller rockers, the ticking could be coming from rockers coming into contact with the cover.

I changed my cover and the new one caused  a ticking and left minor witness marks on the inside of the cover..

 

 

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29 minutes ago, Mark V said:

If you have an alloy rocker cover and roller rockers, the ticking could be coming from rockers coming into contact with the cover.

I changed my cover and the new one caused  a ticking and left minor witness marks on the inside of the cover..

 

 

Good point Mark!

even with standard rockers they can touch the inside of alloy covers, my racetorations cover has witness marks to prove it!

steve

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