ngk plugs ?

[lotusdelta]

hello all,

i know there have been several discussions about spark plugs, but i would like to get a definitive answer about the proper ngk plug for a 72 elan sprint.
ngk web site lists a ngk bp7es (gap .025) as the recommended plug .

others on this sight have listed (ngk bp 5es )as proper.

any ideas.......by the way thanks to whoever supplied the link to ngk site

[Hamish Coutts]

Depends what you're using it for.

Road use go for BP6ES or champion N9Y.
Fast road or track days, I would use BP7ES - don't know the Champion equivalent but will find out if need be.

Remember with NGK the higher the number, the cooler it is. With Champion (and I think, most other makes), the higher the number the hotter it is.

You may find that BP7ES are a bit too cool for general road use and may not self clean too well especially if you get caught up in heavy traffic. (You'll sound like a boy racer because you'll have to keep blipping the throttle to keep the plugs from fouling )

Regards,

Hamihs.

[steveww]

If you are using solid copper plug wire it is a good idea to go for the resistor type spark plug.

NKG BPR7ES
Champion RN7YCC / RN6YCC

FWIW I use the Champion 7 with solid copper wires for general fast road use.

[M100]

After a few years of running with NGK 7's I settled on NGK grade 6's as being more suited to UK summer only usage - usually away from heavy city traffic. I actually use the BKR6ES though because then they are the same as my 90's Elans use (the only physical difference is they are 5/8 hex rather than 13/16)

I found resistor type cables (the carbon or fibreglass type) to be very unreliable in the past, hence the move to copper leads and resistor type plugs. Using non resistor plugs with non resistive leads is also rumoured to cause problems with spark formation.

[Hamish Coutts]

Thinking about the combination of types of lead and the most suitable plugs. I have just fitted blue magnecor plug leads - any advice on whether I should use ordinary or resistor plugs?

Regards,

Hamish.

[Matt7c]

Does anybody tinker with the gap when fitting new spark plugs? I seem to recall that the original spec for the gap setting was quite small (c 0.5mm?) but new plugs tend to come with a gap of at least twice that. What's the word? (and could the gap issue explain my fouled plugs if I set them to the original spec?)

[type26owner]

Matt,
IIRC, NGK recommends you not bend the earth tang to adjust the gap. Doing so causes makes the opposing surfaces to be not parallel. This creates a higher potential field at the smallest gap were the spark will remain stationary rather than move around. This just increases the erosion rate supposedly. They recommend you buy the desired gapped plug and not modify the airgap. That's what I do. Once the sharp edge is gone from the center electrode then the peak intial voltage starts climbing up to still fire across the airgap. Best to keep the peak voltage as low as possible and thereby maximize the current flow. The length of time the current flows determines how well the flame kernal is established in the turbulence.

The gap has no bearing on the temperature the ceramic maintains. The spark plug is just a heat exchanger. The heat range selection determines the amount of heat it removes and in that process whether or not that temperature is in the ideal self-cleaning range.

[Matt7c]

They recommend you buy the desired gapped plug and not modify the airgap. That's what I do.

OK, no more gap tinkering for me . However, as far as I can tell, the recommended (by NGK) plug seems to be the BP7ES, and this comes with about a 1mm airgap. It still works fine, but I wonder whether the Lotus specified smaller gap is necessary, and therefore whether some other plugs are required? What are you using? A bigger spark would seem logical to set the fire, but I don't know whether this is good for the ignition system? I have an Aldon Ignitor with silicone plug leads and no resistor.

[type26owner]

http://www.ngksparkplugs.com/apps/car_truck_suv/results.asp?engineid=27210
The BP 'R' stands for resistor. These NGK Iridium plugs cost over $7 a piece and they are a special order item only where I live. I've given up the NGKs and have started using the common Autolite 64 resistor plugs (.025" gap) which I can buy at any parts house in the USA for about a dollar.

The smaller gap is better on the bakelite dizzy cap since it keeps the peak voltage down and slows the breakdown of the electrical insulation properties of the plastic.

The technical section of the USA and UK NGK website contain different info but compliment each other and they will answer your questions. There is so many popular myths about ignitions systems it's sickening. Simply but the ignorant are sold ignition upgrade components that have no performance value other than the bs hype by unscrupulous aftermaket vendors.

[thor]

Hamish, WHERE did you get the blue magnecor leads from (in the UK), I've been searching for them !

Still don't understand which one is the best plug though, with all this technical terminology about heat and conductivity etc giving me a headache..)

I've got Lumenition and a Lucas gold sports coil. Am I going for Blue magnecor and BP6ES or Champion N9Y ?

Cheers,
Thor

[Hamish Coutts]

Thor,

The site to look at is - http://www.magnecor.com/magnecor1/main.htm

Any Qs please e-mail me at [email protected]

Regards,

Hamish.

[cliveyboy]

Thor
I am using Blue magnecor leads as well. Also Lumenition Optronic and their matching sports coil. I run Champion N9Ys and the plugs do not foul as much as the 7s did.
Magnecor do a set for the twincam. They will also make you a set to your own measurements which is what I would do as I found with the orientation of my dizzy cap one of the leads is a bit short. My leads run over the cam cover.
Picture:- http://groups.msn.com/cliveyboylotus/el ... hotoID=105

One pointer when buying Magnecor leads is that you purchase the coil lead seperately which is handy if like me you have moved the coil.

Cliveyboy

[thor]

AHA, very informative. Hamish: If I order the complete set from the Magnecor pricelist, will I then still need the coil lead as well?
Clive: A VERY silly question; (have only had the +2S130 for a week and spent the time DRIViNG) will I get to the distributor and the coil with the carbs in place? Only asking this of laziness, as I'm at work now..

Thor

[steveww]

With a bit of care the dizzy cap can be removed with the carbs in place.

[cliveyboy]

Thor
Like Steve says the dizzy cap can be removed with our dismantling the carbs.
My Magnecor leads came with the plug numbers marked on them so I just marked up the old leads disconnected them from the plugs unclipped the dizzy cap and removed the whole lot. Swopped over the leads (one at a time) and reinstalled.
Just in case you did not know, although my leads and most peoples run over the cam cover, originally on the later versions (not sure about early ones) the leads enter from the back of the engine and have an aluminium cover over the plugs.
My Sprint should have this but it is a lot more hassle if you want to check the plugs.
Cliveyboy