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Gents

 

I had BPR6EV plugs fitted with less than 100 miles on, when I fitted the triples

 

The difference was discernable, as was the difference between the BP6's and the BPR6EV's

 

I know some have doubts, but, I know how the car felt and there was an improvement

 

John

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Gents

 

 

 

I know some have doubts, but, I know how the car felt and there was an improvement

 

John

John

I'm not so surprised and think plug manufacturers had a Kodak-like attitude to R&D, moving the deckchairs around etc...., for decades up to the '80s. But imposition of emmission controls really forced improved ignition, hence the new designs that we now see. From new players.

For Champion read Kodak. Kodak engineers invented the CCD which is the basis of all digital cameras, the Board ignored their engineers, and the mighty Kodak went bust.

I dont know how the triple electrodes work, but NGK aren't going to let their secrets out any time soon !

Peter

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Peter

The problems with this are many fold as I see it.

I am reporting changes to the way my car feels and sounds, but, this is only my car, with my unique set up.

Any other '6' could and probably will, react differently to the imposition of new plugs as the ignition and mechanics in each car will be set up slightly differently.

And of course, every car has a different human behind the wheel, or head down in the engine bay.

 

There just too many variables.

The only way to get comparable data is Neils rolling road.

 

One thing I am sure of though, I have;

1 set of BP6ES plugs that were in the car when I bought her

1 spare set of BP6ES plugs

Going from one set to the other made no difference

 

I then fitted a new set of BPR6EV gold palladium plugs

These improved starting and cold running, when compared to the BP6ES's. Nothing to write to the Times about, but, an improvement.

 

After less than 100 miles on these, I switched to a set of BUR6ET and again, there is an improvement, not big, but, an improvement.

 

I believe that the switch between BPR6EV and BUR6ET is comparable as both sets of plugs were new, it is the same car, no other mechanical or electrical changes were made and the weather was comparable (dull, miserable and damp)

 

In summary, the change in performance between the BP6ES plugs and the BUR6ET plugs, for me, made the change worthwhile.

 

I would earnesly suggest that other owners give it a try, if they feel there is a need, but, if all is well, just keep doing what you are doing.

 

The most important maxim is; If it aint broke, don't fix it!

 

John

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Neil

Such cynicism from one so young!

 

If it happens, I will have the BPR6EV's in the back, so, a little spannering and I will be on my way.

 

Seriously though, what makes you so certain that they will fail?

You have a great deal more experience than me with these lovely engines, so . . . . . spill the beans

 

John

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MP Iridium: 2447C

MP nickel iron: 1450-1540C

So melting wont be worse with the wire plug !

They are rumoured to be more knock-sensitive, but that could save a piston so I regard that as an advantage.

Peter

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  • 2 weeks later...

Inge

 

It's lasers for me . . . . I want some!

 

I suppose, if we think about it, this is a logical next step. Not necessarily the only one, but . . .

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Peter

The problems with this are many fold as I see it.

I am reporting changes to the way my car feels and sounds, but, this is only my car, with my unique set up.

Any other '6' could and probably will, react differently to the imposition of new plugs as the ignition and mechanics in each car will be set up slightly differently.

And of course, every car has a different human behind the wheel, or head down in the engine bay.

 

There just too many variables.

The only way to get comparable data is Neils rolling road.

 

One thing I am sure of though, I have;

1 set of BP6ES plugs that were in the car when I bought her

1 spare set of BP6ES plugs

Going from one set to the other made no difference

 

I then fitted a new set of BPR6EV gold palladium plugs

These improved starting and cold running, when compared to the BP6ES's. Nothing to write to the Times about, but, an improvement.

 

After less than 100 miles on these, I switched to a set of BUR6ET and again, there is an improvement, not big, but, an improvement.

 

I believe that the switch between BPR6EV and BUR6ET is comparable as both sets of plugs were new, it is the same car, no other mechanical or electrical changes were made and the weather was comparable (dull, miserable and damp)

 

In summary, the change in performance between the BP6ES plugs and the BUR6ET plugs, for me, made the change worthwhile.

 

I would earnesly suggest that other owners give it a try, if they feel there is a need, but, if all is well, just keep doing what you are doing.

 

The most important maxim is; If it aint broke, don't fix it!

 

John

Peter,

As I said earlier, my first experience with 3 electrode plugs was the following: on my Citroen XM it is routeen to change the plugs after 50'000 miles. Instead of throwing the old plugs away, I put the six onto my TR6 carb. I was amazed how much smoother the engine runs and had the feeling it pulled much better.

Upon that I have put 3 electrode plugs (BUR6ET) onto the engine of my sons TR6 PI. Same enjoyable result!

I really cannot see why this kind of plugs should give any problem: mine have been tested over 50'000 miles with success.

Wilfried

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The puzzle is why three electrode plugs should work better than new standard plugs.

There is a whole body of research that shows the plug design has big influence on cycle-by-cycle variability on the flame kernel and its early growth which affects the entire flame progression and torque from that cycle. More cyclic variability gives rougher running.

The main factors five factors are a-e here:

https://supertrarged.files.wordpress.com/2015/02/causes-of-cyclic-variability.jpg

The three electrode plugs will, compared with standard J-electrode:

a) help spark energy deposition if the plugs are old and contaminated with carbon or gaps opened up. But 3e plugs seem to be better than new standard plugs.

b ) flame kernel motion will be more constrained by3e plugs. Can that help? -yes, but only if the squish tends to 'blow out' the early spark kernel in standard plugs.

c) heat loss from kernel to plug earth electrodes will be worse in 3e, and will worsen combustion.

d) local turbulence will be less with 3e. Swirling turbulence can change rapidly around a plug tip, and helps flame growth. So too little might not help combustion: slow kernels stay slow.

e) local mixture near plug. Poor turbulence around a plug would mean that a spark in a lean mixture stays slow-burning without rescue by a rich micro-eddy.

 

So the only reason I can see for 3e plugs being better is because the TR6 head has too much squish turbulence and the more extensive earth electrodes protect the early spark from the squish.

The test is to try new 3e plugs against new standard plugs in a low compression USA-spec head eg 8.5:1.whose squish will be poor or absent.

And the 3e plugs should work better in high compression racing heads with higher squish than stock compression.

 

Peter

Edited by Peter Cobbold
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Hi All.

Well I went and did it, and yes there is a definite improvement. It obviously could be psychological but only time will tell.

Glad I took the plunge, looking forward to some long runs.

Mark

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Mark

If it's psychological, then there are a lot of us out here suffering.

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The puzzle is why three electrode plugs should work better than new standard plugs.

 

Peter

Peter,

In the 3-, 2-, 4- electrode configuration the central electrode AND THE SPARK is SEEN by the gas in the combustion chamber. It is not hidden by the ground electrode. Seeing the spark means beeing exposed to be ignited easier, faster, more reliably.

I know, you are an expert in this field. Is the above reason just too simple to explain better combustion?

 

I have been working with Lasers over 7 years before my retirement, used the the laser to produce sparks for spectroscopical reasons and also for evaporating material. At that time I dreamed to use them for igniting the gas in an engine. The necessary hardware at that time was 100 times too heavy and 500 times too expensive for that purpose. I am glad to read now, that this dream is not any more just a dream!

 

Wilfried

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Peter,

In the 3-, 2-, 4- electrode configuration the central electrode AND THE SPARK is SEEN by the gas in the combustion chamber. It is not hidden by the ground electrode. Seeing the spark means beeing exposed to be ignited easier, faster, more reliably.

I know, you are an expert in this field. Is the above reason just too simple to explain better combustion?

 

I have been working with Lasers over 7 years before my retirement, used the the laser to produce sparks for spectroscopical reasons and also for evaporating material. At that time I dreamed to use them for igniting the gas in an engine. The necessary hardware at that time was 100 times too heavy and 500 times too expensive for that purpose. I am glad to read now, that this dream is not any more just a dream!

 

Wilfried

Wilfried,

I think the turbulence in the chamber is so extreme that the spark gap sees mixture coming from many different directions cycle by cycle. It is an established phenomenon - the spark kernel blows away form the gap differently each cycle ( see blog post on combustion basics).

In the other thread I found a paper showing the muliple grounds make cyclic variability worse by increased cooling of the early flame. Here:

http://www.tr-register.co.uk/forums/index.php?/topic/51042-bosch-4-electrode-plugs/?p=416143

And in the following post I suggest the multi ground electrodes allow the central cathode to run hotter and reduce the break down voltage needed.

That would also explain why wire electrodes also work better in TRs, the small diameter cathode reducing the required break down voltage.

The breakdown phase of the spark is very brief but needs MW power levels (high voltage and current) so easier discharges may improve the spark.

 

I do wonder how the laser window into a combustion chamber will be kept clean from carbon, oil and so forth !

 

Peter

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  • 7 months later...

Cant be long now before we see corona discharge ignition. Instead of point-sized ignition the corona initiates combustion over a very large volume, with considerable benefits to combustion. 'Ecoflash' page 8

http://emissions.borgwarner.com/download/produkte/borgwarner_ignition_coil_technology_en.pdf

Peter

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  • 2 years later...

What a thorough discussion on spark plugs! My TR6 has developed a misfire after leaving it in the garage for a month or two. The MU and injectors were recently overhauled (less than 500km ago) and were perfect when I left the car after the last run, I can still feel pulses in all 6 injector lines..

 

After reading this , and other similar threads, I suspect that the newish NGK BP6ES plugs have fouled on stale fuel and are intermittently misfiring.

 

I need to know if NGK BUR6ET are still a preferred plug for TR6's in a fast road state of tune.

 

Thanks.

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What a thorough discussion on spark plugs! My TR6 has developed a misfire after leaving it in the garage for a month or two. The MU and injectors were recently overhauled (less than 500km ago) and were perfect when I left the car after the last run, I can still feel pulses in all 6 injector lines..

 

After reading this , and other similar threads, I suspect that the newish NGK BP6ES plugs have fouled on stale fuel and are intermittently misfiring.

 

I need to know if NGK BUR6ET are still a preferred plug for TR6's in a fast road state of tune.

 

Thanks.

 

I still use NGK BUR6ET in my near-standard CP-Series TR6 and in my GT6. When the plugs eventually need replacing - not for a long time because they can tolerate much higher mileages than single electrode plugs - I will fit the same again.

 

I've also fitted BUR6ET in the Ford Essex 3 litre in my Scimitar GTE, with similar slight improvements in smoothness of idling and accelerator pick up. For me, the longevity would be reason enough to use multi-electrode plugs, even if there was no other benefit.

 

 

Nigel

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I still use NGK BUR6ET in my near-standard CP-Series TR6 and in my GT6. When the plugs eventually need replacing - not for a long time because they can tolerate much higher mileages than single electrode plugs - I will fit the same again.

 

I've also fitted BUR6ET in the Ford Essex 3 litre in my Scimitar GTE, with similar slight improvements in smoothness of idling and accelerator pick up. For me, the longevity would be reason enough to use multi-electrode plugs, even if there was no other benefit.

 

 

Nigel

 

+1

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Fitted the NGK BUR6ET plugs and went on a run through the mountains in NE Victoria. Can highly recommend them - the car climbed flawlessly with huge amounts of torque- well worth the $96 (54 pounds) the set of plugs cost.

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Interestingly, someone who is no longer a contributor to this forum was totally against the use of this type of plug claiming that to do so would result in engine failure. Whilst I found a lot of his advice very useful, I just couldn't fathom the logic in his opinion on this matter and he refused to elaborate. Being involved in the trade (motorcycles), I decided that he was wrong on this count with no justification for his argument so went ahead and fitted them.

 

Does anyone know exactly what his objection was based upon?

Edited by KiwiTR6
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