Spark Plugs

[Stanpartmanpartwolf]

Here it is. "All total bollox". No prices naturally. The poor old boy's lost it again.

[Alec Pringle]

I'd have thought there are quite a few Forumites with experience of dyno testing, one way or another, and I can think of several with experience of comparative back to back engine and chassis dyno work, in conjunction with track testing.

 

They may not, of course, wish to brag too loudly of their experience and achievements . . . . but that does not devalue their observations.

 

It isn't good form to be unnecessarily and peremptorily dismissive of the thoughts of others, conduct unbecoming.

 

To be fair, replacing a set of knackered old plugs with anything even vaguely suitable but new and sparkly is likely to be an improvement . . . . at least in the short term.

 

Some of the more exotic looking plugs I've found in the past to offer more hype than result, whereas other varieties do seem to have offered measurable improvement and subjectively more satisfactory operating characteristics.

 

I certainly wouldn't wish to generalise, different plugs do seem to behave in differing fashions, and a type that works well in an Audi, for example, doesn't necessarily seem to do such a good job in a Rover, and vice versa.

 

Most of us contributing to discussions on Forum are, I would suggest, looking to make the best of our relatively ordinary TRs on our relatively restricted budgets, utilising what's available off the shelf - esoteric and potentially expensive theoretical concepts of lean burn technology are unlikely to appeal to the average TR Forumite.

 

Pearls before swine perhaps, but then beauty is in the eye of the beholder.

 

Cheers

 

Alec

[Alec Pringle]

For the benefit of those unfamiliar with GTT's past endeavours, his website is worth a look through, the Triumph Modified Cylinder Heads page I find especially entertaining.

 

http://www.jagclub.ru/triumph_tun.html

 

Cheers

 

Alec

[Peter Cobbold]

How's this for a big spark?

http://articles.sae.org/12102/

 

Peter

[littlejim]

Here it is. "All total bollox". No prices naturally. The poor old boy's lost it again.

That 'lean bum' technology is pretty convincing, especially for overweight drivers.

[TriumphV8]

How's this for a big spark?

http://articles.sae.org/12102/

 

Peter

I know about the possible advantages of sparking at two places from the Porsche 964

and many small airplanes. The last have to be tested before flight with one magneto off

and one can immediately watch a drop of power.

 

As with the 3 electrode plug the spark still only jumps at one place the ACIS

seems to become a big approvement.

I want to believe that position, where the spark jumps, makes a difference

but the middle electrode can not be projected that far especially with colder plugs

like our engines would require.

 

Up to the time one can buy that ACIS I rely on multiple spark (at low revs) of MSD6

what honestly makes no difference in feeling how the engine runs.

 

Fireing the mixture at two places in the 964 adds if I remember right about 8PS

that can not be projected to a TR6 because combustion chamber is much smaller.

[JohnG]

Gents

Good morning

 

I really did not intend to spark (pun intended) the sort of 'heated' debate that has been appearing recently

 

My problem was apparent unreliable spark strengh and quality causing poor cold start and running

 

I came to the forum because I was sure you guys would have had similar issues and be able to offer a number of potential remidies.

I do not have to measure the level of poor start and running to know it exists

I do not have to put my car on a rolling road to prove the problems exist; I know they do

Having said that, I recognise that to measure the depth of the problem and put (in my case un-needed) figures against it, testing and measurement are essential.

All I want is more reliable cold starting and running

I would like to try triple electrode, if anyone can give me a part number

 

Many thanks all for the help and advice, it has made interesting reading so far

 

John

Edited December 18, 2014 by wjgco

[Peter Cobbold]

I know about the possible advantages of sparking at two places from the Porsche 964

and many small airplanes. The last have to be tested before flight with one magneto off

and one can immediately watch a drop of power.

 

As with the 3 electrode plug the spark still only jumps at one place the ACIS

seems to become a big approvement.

I want to believe that position, where the spark jumps, makes a difference

but the middle electrode can not be projected that far especially with colder plugs

like our engines would require.

 

Up to the time one can buy that ACIS I rely on multiple spark (at low revs) of MSD6

what honestly makes no difference in feeling how the engine runs.

 

Fireing the mixture at two places in the 964 adds if I remember right about 8PS

that can not be projected to a TR6 because combustion chamber is much smaller.

Andreas,

Yes, I too would like multispark igntiton but I think I recall that the MSDs deliver just one spark at 2500rpm, which is when I'd want several.

 

Even on the TR6 chamber starting the flame with that corona over such a big volume should reduce

combustion cycle-by-cycle variability greatly. With spark timed perfectly for all cycles there should be benefits for both lean burn and full power ( less advance needed). But I doubt an aftermarket kit will be made!

 

Laser ignitors, plasma jet aim at the same effect - a big ignited volume.

There are also multi jet jet plugs, mostly experimental.

Here's one on sale: eg http://www.multitorch.de/index.php?seite=home

I think they are mainly intended for big-cylinder natural gas engines operating at slow rpm. Cant see that working on a TR6!

Peter

[TriumphV8]

Yes, the MSD fires two sparks only up to somewhat 2500 rpm,

depends also on number of cylinders and availiable time.

There would be a problem if the MSD fires additional sparks too long and the finger might touch

the pin in the cap for the next cylinder and fire that mixture much too early.

 

It is just a gimmick that might help at low revs.

 

Better help is the extended spark plug gap up to 1.2mm

that allows MSD to meet more fuel particles to fire.

 

With no doubt both the plane engine and the Porsche have big combustion chambers

with long ways for the flame front and benefit more from double sparks.

But if I remember correctly also a smaller chamber will benefit, too

but not that much and maybe not worth the effort.

 

But as I use up to 45 degrees of ignition advance in the TR6

this gives me an indication that the fuel needs its time to ignite

and there is potential if there would be a way to get that quicker.

[Nigel Triumph]

I've been using Bosch 4-electrode plugs for about 10 years.

 

I first fitted them to my GT6 with a standard engine on Stromberg carbs, already using Aldon Ignitor Hall effect ignition and Flamethrower coil. I replaced newish NGK's with Bosch WR78's. The GT6 immediately showed smoother tickover and felt "crisper" through the rev range. No dyno measurements to back this up of course but there was a clearly discernable difference. I didn't notice any difference in how easily it started but it always starts quickly in any kind of weather (once the mechanical pump has got fuel to the float chambers). The Bosch plugs have now covered 30,000 miles and I can't see any reason to replace them in the near future.

 

After the positive result with the 2 litre engine, I fitted WR78's to the TR6 (CP series still running Lucas PI), also fitted with Aldon electronic ignition and coil. The engine is standard apart from a Phoenix 6-3-1 exhaust - better duck for cover now I've admitted this dirty little secret! The same benefits were apparent on the Bosch plugs as with the GT6. I'm a believer in multi-electrode plugs.

 

 

Nigel

[JohnG]

Many thanks

I will give WR78's a go, once the weather lets up.

 

I have been fettling for a while, just to smooth cold/cool running.

I recently fitted fine wire NGK 6EV plugs which improved the cold start and running, but, based on what has been said, multi electrode seems to be way to go, so, I'm giving it a try.

[Mark Shezbo Sherratt]

Dunno about power and torque but I can definitely detect running differences between single and triple electrode plugs with my Triumphs, with the triples being the winner, even when comparing high mileage triples with new singles - which is how I discovered it in the first place.

 

Also, with the our old K-jet GTI, we had all kinds of cold start issues with it until fitting triples as recommended by a local independent. I didn't believe him for a moment, but I was getting desperate. Immediate cure.

 

I thought you were a believer in the importance of plug technology?

 

 

Nick

Hi Nick,

 

Thanks for the info - sorry just to be clear - please state the plug make and part number you have talked about and taken a picture of (I assume that they require no mod's) - appreciated Mark

[Guest ntc]

You may find this interesting,http://www.imps4ever.info/tech/engine/sparking-plugs-spark-plugs/spark-plugs.html

[Wilfried]

Gents

Good morning

 

All I want is more reliable cold starting and running

I would like to try triple electrode, if anyone can give me a part number

 

John

 

The plugs are made by NGK and are called BUR6ET.

Wilfried

[Nick Jones]

Hi Nick,

 

Thanks for the info - sorry just to be clear - please state the plug make and part number you have talked about and taken a picture of (I assume that they require no mod's) - appreciated Mark

 

 

Mark,

 

The ones I've mostly been talking about are conventional triple electrode plugs. My favourites are Bosch WR7DTC, but NGK BUR6ET are a close equivalent.

 

The ones pictured are Russian and not easy get here. My set came from Gareth some years ago and we messed about with them in my Vitesse to see how how lean we could go at idle (about 17:1) and at light throttle cruise (again 17-18:1 before hitching set in), which was significantly leaner than with normal plugs (single or triple electrode). My programmable EFI meant we could adjust the mixture very easily and see the the actual AFR read back from the wideband O2 sensor. I think they got potential but I stopped using them as they (in combination with the crappy plug leads I was using at the time) intermittently caused interference with the ECU. I've got better plug leads and ECU now so should try them again.

 

Nick

[JohnG]

Gents

Thank you

I will look at all 3 of the multi electrode options supplied and, if I am honest, probably stick with one of the NGK options.

 

I've just read the sentence above, it make me sound narrow minded regarding plugs, sorry, I just know and trust NGK, but, will seriously look at the Bosch ones

 

As always, thanks to everyone, all the advice

 

John

Edited December 20, 2014 by wjgco

[Prefect]

Hi!

 

I changed from BPR6ES to BPR6EIX the fine electrode Iridium type. I noticed the difference as soon as I turn the ignition key. The engine started up instantly, runs with less choke, revs better across the whole rev range, less sooting on number 6 cyl, heater works quicker form cold, less throttle required at 70 MPH.

I have spoken to a number of people who are using them and we all say the same thing!!!!

 

The only downside is that they are expensive but if you shop around on the internet they can be bought for £6 each and they are designed for high energy ignition systems. I would think that you have to use a 40k/v coil as a minimum to start to get the best out of these plugs. They are designed for CD ignition systems which operate up to 60k/v on modern cars and to burn the current type of petrol, which the old thick electrode plugs were not.

 

Bruce.

Hi Bruce

I know it has been a while since you posted this but how did you set the gap on the Iridium plugs?

[Wilfried]

Hello John,

I guess you will soon buy six 3 electrode plugs and put them in your TR6.

We, who have been encouraging you to do so, are obviously interested to hear from you how the engine performs after the change.

Please let me know, when we can exspect your report!

Wilfried

[JohnG]

Wilfred

Rest assured, as soon as the plugs are in and the weather offers a gap in the rain, I will report back

 

I have had BPR6EV plugs in for the past couple of weeks and they are a very distinct improvement over the ES type.

 

I plan to buy and fit multi electrode (Bosch or GKN) plugs within the week, so hope to report back by early in the new year.

 

John

[Peter Cobbold]

 

I would be very interested to see them tried again....and they're NOT RUSSIAN,- the electrodes are from Hungary.

We're doing some work with them on a 4V engine which is genuinely designed as "lean burn".

It looks very encouraging.

 

 

Gareth, Nick,

The three apertures remind me of Citroen precombustion chamber plugs:

from 1935:

http://www.freepatentsonline.com/2047575.pdf

and more recently:

http://www.freepatentsonline.com/7104245.html

http://www.freepatentsonline.com/7104245.pdf

 

I think I remember reading that the mixture ignited by the spark within the chamber expands and sprays jets of 'free radicals' ( apparently not flame) through the apertures and these then ignite the fuel over a bigger volume outside the plug. Yes, it in the patent:

 

"".....said precombustion chamber body is made of a material having a thermal conductivity at 20° C. of at least 10 W/K/m, wherein said passageway(s) are capable of preventing the propagation of a flame front while enabling the propagation of unstable compounds derived from the combustion of the reactants contained in the precombustion chamber, the compression system of the main chamber and the seeding of the main mixture with said unstable compounds enabling mass self-ignition of the main mixture...."

 

 

That helps lean burn.

"Notably, the present invention concerns an ignition device for internal combustion engine which may exhibit the following advantages:

• • reduced enrichment in fuel of the air-fuel mixture when the engine operates on full load,
  • reduction, possibly suppression of the pinkling, which enables to increase the volumetric ratio of the engine,
  • better productivity of usage of the oxidant and of the fuel.

 

 

I did wonder how fast the plug chamber refills with ignitable mixture- does the plug limit rpm?

 

When I get the leaning device running on the SU I'd like to try the Hungarian plugs. I'll be able to lean as I drive.

 

Peter

Edited December 21, 2014 by Peter Cobbold

[Nick Jones]

Interesting. I think it is the same idea in a slightly different form.

 

Also related, tackling the same idea (more turbulence, faster burn) are the Somender Singh grooves. I'd like to try that but my Vitesse head has had such a huge skim I'm scared to remove anything more from the squish platform......

 

Nick

[Fireman049]

I'd like to fit triple electrode plugs to my 3A. My car has a 2.2L engine.

Which plugs are suitable (NGK?).

 

Thanks ~

Tom.

[astontr6]

Hi Prefect,

 

In response to your question, how do you gap the NGK Iridium Plugs you don't! Leave as they are supplied! One thing that nobody has really pointed out is that the thin wire plugs are a Jap answer to todays fuel blend, if Honda & Co use them they cannot be rubbish. Their advantage over the 2,3 and 4 electrode types is they offer less resistance to spark, this equals a bigger spark.

Note: the earth terminal is chopped as well.

 

Therefore, when used with the Pertronix Ignitor 2 unit which has a micro processor in it unlike the original version. The Ignitor 2 senses the current levels in the

coil and adjusts the dwell to maintain peak energy throughout the rev range. They state that the MK2 version nearly doubles the plug voltage in the 3000 to 4000 RPM Band over the

original MK1 type.

type. But one has to use their 0.6 ohm Flame thrower Coil, rated at 45Kv.

 

If you want more spark still you can add the MSD CD Streetfire unit!!!!!

 

Bruce.

[stuart]

I'd like to fit triple electrode plugs to my 3A. My car has a 2.2L engine.

Which plugs are suitable (NGK?).

 

Thanks ~

Tom.

Tom they dont AFIK make a short reach version suitable for a 4cyl TR engine, we went through this ages ago as Menno was interested in trying them.

Stuart.

[Fireman049]

Thank you Stuart ~

 

Tom.