Spark Plugs

[JohnG]

Gents

 

My 6 has;

- NGK BP6ES plugs

- Luminition electronic ignition

 

I plan to change the plugs.

Is there any reason why I should not install NGK BPR6EV Gold Palladium plugs as replacements?

 

I understand that the 'R' indicates that the plug has a resistor fitted.

This should, I feel, be mated with an electronic ignition

I like the fine electrode on the 'V' plug, as I believe that it offers a hotter burn

 

Your thoughts would be greatly appreciated

 

Thanks

 

John

Edited December 2, 2014 by wjgco

[TriumphV8]

Good chance to measure the whole resistance from the cap to the dip of each plug.

All in all there should not be more than 5 KOhm.

 

I like the BP6ES and tested them against the expensive Platin tip and did

not find any advantage. I think the theory behind the expensive plug is that

small tip needs better material to last long and the spark can cross the gap easier.

 

Found this on the web, funny way to get rid of the resitor inside:

 

I tend to use the spiral wound wires with much less resistance and good supression.

If there is no problem with the radio I would not use resistor plugs.

If somebody is on copper wires that might be a reason to use resistor plugs,

[astontr6]

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.

[Peter Cobbold]

Bruce

I shall be going to those iridium 'wire' plugs too. The smaller diameter electrode will make a longer length spark for the same HT, or a hotter spark for the same gap. This allows it to fire lean mixtures more reliably. So there's lot of science behind the improvements you notice

I shall be keeping the stock coil and points - the plugs effectivley do the job of more HT. And the disy cap might not like more HT- -the last thing I want is cross-firing under boost. The wire plugs also fires boosted mixture better, and foul less easily.

Wire plugs are reported to be more susceptible to detonation - which I regard as a plus feature ! it could save a piston.

I have not yet found the heat equivalence of wire plugs to the stock plugs.

Peter

Edited December 5, 2014 by Peter Cobbold

[astontr6]

Dear Peter,

 

The NGK part number that I quote in my previous email is the one that NGK UK gave me and if you look on their US web site you see it is the same number. I still did use my original genuine LUCAS Sports Coil until last year, the ones that you buy now are not genuine LUCAS. The trade name belongs to Delphi who have licensed another manufacturer, who is a Danish Co, to use it! People tell me that their quality is not consistent?

 

My original sports coil puts out a genuine 40k/v Tested two years ago ( (over 35 years old). I never had any trouble with the Dis. until I changed the rotor arm, to one of those non genuine made LUCAS ones. Then I bought one of Dis Docs red one and no trouble, that was 3 to 4 years ago. The Dis Cap seems to be able to deal with this voltage but I am still using a genuine LUCAS one (20 years old.)

 

The reason why that I changed the coil was that I had an very old Luminition system and I wanted something more up to date. So I decided to go for the Pertronix Ignitor 2 ( latest version) with their low resistance 0.6 ohm coil giving 45k/v. I certainly noticed a difference with this mod. when you wind the engine up over 2000 RPM. This I bought direct from Summit Racing in the US who ship to the UK using UPS I- Parcel on a DDP bases. This means you know exactly how much it is going to cost you.

 

Bruce.

[Peter Cobbold]

Dear Peter,

 

The NGK part number that I quote in my previous email is the one that NGK UK gave me and if you look on their US web site you see it is the same number. I still did use my original genuine LUCAS Sports Coil until last year, the ones that you buy now are not genuine LUCAS. The trade name belongs to Delphi who have licensed another manufacturer, who is a Danish Co, to use it! People tell me that their quality is not consistent?

 

My original sports coil puts out a genuine 40k/v Tested two years ago ( (over 35 years old). I never had any trouble with the Dis. until I changed the rotor arm, to one of those non genuine made LUCAS ones. Then I bought one of Dis Docs red one and no trouble, that was 3 to 4 years ago. The Dis Cap seems to be able to deal with this voltage but I am still using a genuine LUCAS one (20 years old.)

 

The reason why that I changed the coil was that I had an very old Luminition system and I wanted something more up to date. So I decided to go for the Pertronix Ignitor 2 ( latest version) with their low resistance 0.6 ohm coil giving 45k/v. I certainly noticed a difference with this mod. when you wind the engine up over 2000 RPM. This I bought direct from Summit Racing in the US who ship to the UK using UPS I- Parcel on a DDP bases. This means you know exactly how much it is going to cost you.

 

Bruce.

Thanks Bruce, its good to know the disy cap copes with that voltage. Mine is also 20 years or so old !! I was going to try to get hold of a obsolete Bosch transformer coil from Oz as it gives a usefully longer duration discharge compared with normal coils. But I'lll try the Pertronix instead.

I am going to DisyDr for a red rotor arm, the existing one is also 20years old. TG for the forum revealing the poor aftermarket parts, sold by the name on the box.

I have to be very careful with the disy cap and HT - if it cross-fires and ignites a cylinder with the inlet valve still open there will be an almighty explosion of the boosted mixture in the inlet plenum and ducts - not ideal for the blower.

Peter

[Wilfried]

When we changed the six plugs on my Citroen XM (after 80 tkm), they looked still very good. They are of the 3 electrode type.

Rather than get rid of them, I mounted them on my TR6 (carb) by curiosity. I was most surprised: the engine seems since then to run much smoother.

As my son has also a TR6 (PI) we bought 6 new NGK platinum with 3 electrodes. Unfortunately we were not able to remove the little round nut on top of the plugs: the cables are meant to be connected on a thread top of plug.

We realized that our NGK plugs have no-removable round nut. We should have made attention to this, but did not know that this exists. As the plugs were rather expensive (10£ a piece), it is probably cheaper to change the 6 caps at the end of the HV cables.

Has anyone also tried 3 electrode plugs on the TR6?

Wilfried

[Mk1PI]

When we changed the six plugs on my Citroen XM (after 80 tkm), they looked still very good. They are of the 3 electrode type.

Rather than get rid of them, I mounted them on my TR6 (carb) by curiosity. I was most surprised: the engine seems since then to run much smoother.

As my son has also a TR6 (PI) we bought 6 new NGK platinum with 3 electrodes.

Has anyone also tried 3 electrode plugs on the TR6?

Wilfried

NGK BUR6ET are very cheap on ebay and work very well in all my Triumph sixes

 

Standard figment to VW of many varieties

 

http://www.ebay.co.uk/itm/4-NGK-PLUGS-VW-GOLF-MK1-1-6-82-84-BUR6ET-/360147854709?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item53da7c2575

Edited December 9, 2014 by Mk1PI

[Wilfried]

NGK BUR6ET are very cheap on ebay and work very well in all my Triumph sixes

 

Standard figment to VW of many varieties

 

http://www.ebay.co.uk/itm/4-NGK-PLUGS-VW-GOLF-MK1-1-6-82-84-BUR6ET-/360147854709?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item53da7c2575

Thanks for that hint! I guess that on these plugs one can unscrew the little rounded nut?

Have you heared or read from other TR sixes owners about using 3 electrode plugs?

Wilfried

[Nick Jones]

Yes, I've been using 3 electrode plugs in Triumph engines for about 15 years now - usually Bosch ones. I've written about it on here before. I discovered the benefits by accident when, having flooded my Herald engine, the only dry plugs I had available were an old set from a Golf GTI. The Herald ran better than ever, but less well when the "correct" plugs were re-installed. I bought some new Bosch triples ones for it and have never looked back.

 

I also use them in my Vitesse 2L and did have them in my PI saloon also. They both definitely work better with the triples. The GTIs we've had also ran much better with triples. I can only think it is something to do with the triples being what is effectively a side-electrode design.

I usually use WR7DTC, which are resistive and suit the engine management and distributorless ignition I'm using.

 

Nick

[Mk1PI]

Those NGK triple electrode plug cured a top end miss that new BP6ES Didn't cure on my PI track car - they really helped the TR6 too - happy to try Bosch too

Edited December 9, 2014 by Mk1PI

[Nick Jones]

The triple electrode arrangement seems to bring benefit regardless of brand. I've also used the NGK BUR6ET to good effect, just slightly off NGK having lost a few to petrol wetting when my PI was still Lucas fuelled.

 

Nick

[JohnG]

It would appear that there is a preference for triple electrode plugs.

 

I will take a look at both fine wire and triple, but first, can you help with an NGK or Bosch number?

 

Thanks

 

John

[Wilfried]

I have an explanation, why 3 electrode (or 2 electrode) spark plugs are better than the usual plugs.

Immagine you are the compressed gas and you look at the plug, looking for a spark.

 

- In our usual plugs the spark is hidden behind the single ground electrode.

- In the 3 electrode configuration, the spark is entirely visible.

 

Which configuration do you think is more effective to ignite the mixture?

Wilfried

[RogerH]

Hi Wilfried,

if it is the obscuring of the spark by the earth electrode on a conventional plug that may cause poor performance then there are a couple of things that can be done to help things along.

 

1, Indexing - you can put washers under the plug to ensure that the earth electrode is away from the ignition spark.

2, You can drill a hole (1/16 or smaller) through the earth electrode immediately in line with the centre electrode - this has the affect of drawing the spark more+ directly to the earth electrode.

 

Roger

[Peter Cobbold]

Or cut the earth back so the spark occurs between sharp edges:

http://i.imgur.com/PRVpu.jpg

- and replace them more often!

Peter

[Nick Jones]

I have an explanation, why 3 electrode (or 2 electrode) spark plugs are better than the usual plugs.

Immagine you are the compressed gas and you look at the plug, looking for a spark.

 

- In our usual plugs the spark is hidden behind the single ground electrode.

- In the 3 electrode configuration, the spark is entirely visible.

 

Which configuration do you think is more effective to ignite the mixture?

Wilfried

 

Wilfried,

 

Yes, I agree completely - that is my theory also.

 

Peter, Roger

 

Easier to fit the triple electrode plugs than indexing standard ones or chopping their electrodes off - and they last a long time too (which is the original reason for the design)

 

Nick

[Peter Cobbold]

Tripod electrodes seem to me to offer three times the opportunity for the early kernel to be extinguished, compared with conventional earth.

http://www.ngksparkplugs.com/pdf/dyk_mge_spark_plugs.pdf

To get the best lean burn from wire plugs I intend indexing them so that earth electrode is out of the line of the squish jet, and not obstructing flame spread towards the exhaust valve, to reduce risk of knock. Which puts the electrode on the side of the plug nearest the inlet valve, where it should cause the least disruption to kernel growth.

Peter

Edited December 11, 2014 by Peter Cobbold

[Wilfried]

Peter,

I have no doubt that an expert like you can get with indexing an ignition as good as with a triple electrode plug.

But there are so many non experts who merit to have their engines running nearly as nice as yours. For those I have put in this forum the suggestion to mount triple electrode plugs like NGK BUR6ET. They cost maybe twice the price of normal plugs, but last at least 4 times as long and give immediate satisfaction.

Wilfried

[Tom Fremont]

Seems the "6" heat range suits the P.I. setup.

 

I've done over 100K miles with "7"s on my '250 with P.I. cam/head and triple Webers. The "6"s burned white.

 

Lucas Sport Coil, points and NGK BP7ES set to 0.030". The longest I've left them in is circa 30K miles, but new ones behaved no differently.

 

Aside from the rotor arms, those who use points have to contend with bad condensers nowadays; the current variety of which may work partially instead of not at all. I've heard tell that some enterprising folks have produced some reliable ones...

[paul7]

I've not actually seen the 3 electrode plugs but how is the gap set so all 3 are the same? there must be an easy answer

[Peter Cobbold]

I've not actually seen the 3 electrode plugs but how is the gap set so all 3 are the same? there must be an easy answer

I think they are expected to be fit and forget, so not adjustable.

Peter

[RobinTR6]

Yep, fit and forget, no need to set gap. Had mine for a while without issue and yep does seem to run a bit better.

[John L]

As one gap wears between one leg it will jump the next nearest, they don't spark on all 3 at a time, that's why they last so much longer.

John

[Nick Jones]

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