Classic Alfa Forums

OK people this is well old school thinking but has anyone had experience of indexing plugs and would it be beneficial on our Boxers? I'm thinking more of emissions (mot) rather than power gains but both would be good. Waits with interest. Tony

I haven't heard of indexing, what does it mean?

It's the orientation of the plug electrode relative to the valve position so as to give a more efficient combustion across the piston - or so the theory goes.

never heard of that mate, do you mean so you end up with the electrode pointing in a certain deirection once in the head? i'd be surprised if it made a huge difference to be honest but would be keen to hear the theory

That's the aim of it Kev,maybe I am officially an old git if you haven't come across this before. Hope someone comes and rescues me else you'll think I made it up. Maybe Ted or John-Shrew might done it with bikes. I won't even mention side-gapping.

Don't see how indexing would really work with Golden Lodge plugs, which have 4 electrodes anyway??

But it is an interesting question as to who still sticks with Golden Lodge plugs and thinks them worthwhile.

cheers

eib

The whole picture and aim of indexing is to have the spark facing the incoming fuel charge, as opposed to having the (single) spark electrode shielding the spark by having its back to the fuel charge direction, if that explains it any better?

the idea being a more complete burn of the fuel and all the benefits from it.



i know of it, have never tried it, bike or car, but i strongly suspect that in anything made this side of the 1st world war it would be a tedious and yet largely pointless exercise


i think there is far more benefit to be had from a decent NGK plug choice, nothing far too exotic, regularly changed and properly gapped.

Golden Lodge plugs? they wouldnt grace any of my engines today i'm afraid,


Just like flares and platforms, they should have died in the 70's!

What plugs do you recommend then Shrew?
I thought lodge were ok.
Looks like I need some better plugs then.....

In my opinion, Golden Lodge are still installed by some because Alfa did back in the day from the factory, so it serves a purpose as a genuine fitment thing for those that want it.


would anyone fit a 1970's champion plug to their car? I certainly wouldn't, but is the Golden lodge any better simply because Alfa fitted it at the factory? No!

Its an old design, using old technology and materials, and everything else was different then too remember, i.e. fuel, ht leads materials, coil, even your dizzy rotor arm was probably slightly different materials too!


Now i don't dismiss it entirely, because i'm a huge fan of a straight forward copper core electrode, and that's why wherever possible, i fit a standard NGK version plug. No super exotic materials, no need for multiple tips too either really, but you can't always get away from it, and where possible, no R for resistor either, it only reduces the spark strength in an effort to stop the neighbours Lambretta interfering with Coronation Street!

NGK in everything, literally everything for me personally, but as standard as i can find, no fancy stuff.


Now if that sounds similar to the Golden Lodge plug anyway, the final reason i would fit iot os because although there are many new old stock plugs around to buy, how old are they really?

I personally wouldn't like the risk of old fatigued materials, and a plug electrode breaking off ruining the bore, for the sake of originality!

I've seen it happen in a few bike engine over the years, and a couple of car motors too, and its not nice


B7ES i think would be my choice for a Sud Keith.

They come 0.6mm gap i believe, but i don't think 0.7mm would hurt and super plus fuel everytime.




As a final note on the material choice. I try to steer clear of all the exotic plugs such as Iridium, Platinum etc.

These materials are chosen simply for their hardness in comparison to copper, and therefore their durability in resisting spark erosion.

This is why they are a common fit on modern cars, because changing the plugs in many cars is now a half day wrestle match, and because the manufacturers like to guarantee that the plug wont stray from tolerance for 50-60k miles.

BUT, neither Iridium or Platinum have the electric conductivity of copper, and are less thermally conductive too, so tend to run smaller sparks and hotter rather than dissipate the heat away.

these two factors are bad for performance of the plug itself to deliver an ignition spark as and when precisely when and where needed.


the bonus, even in cars that dont do much mileage anyway, is that changing the cheaper plugs more often will result in always having the best spark possible from the other components on your current ignition system, and a far younger more reliable plug installed at all times.

i don't see any con's, only pros



Nology, are punting out silver cored plugs, which materially is a match for copper and some, so i'd be up for a trial of those over an NGK, but nothing else currently.


Hope this essay has some salient points Keith?

WOW !! thanks Shrew,
I get your point about the "NOS" plugs. Hadn't thought about it that way.
I will get myself a set of NGK 's this week.
Got a few jobs to do over the winter on her.
Cheers
Keith

I use B7ES in my modified Sprint with no issues at all. Another plus is the pricetag compared to GL

NGK for me also......the '7' rated one.

Tried the Bosch multi tip but found I had to change them about every 4 races so stuck with NGK (I used to buy them at my local motor bike shop)

I think the last set of NGK cost £12 and the rolling road guru fitted and advocated them also - he had them on the shelf so clearly used them often.

I havnt seen a lodge plug since they were pink, so a long time ago.

Another vote for the B7ES then eh Tim.


Back to the Indexing query Tim, have you ever done that or known anyone who did?

It seems a lot of folk know of it, but have no actual experience of it, myself included.

Never heard of it Shrew.....however I wil mention it to the chief engineer and see if he has come across it

guessing the simplest way to do it is to mark a line on the white outer part of the plug that corresponds with the electrode and keep adding washers until it lines up where you want it?

hmmm, but then youre potentially pulling the spark away from the flame path.


not too hard to do when a plug is new, because the washers are thick and soft, so you can have a good turn on it to get the marks to line up, but once they've been compressed a time or two, you run the risk of them being too lose or over tight to get it aligned.


i still believe its relatively pointless, although the notion itself is practically a sound idea

yes, i too think it's pretty much a dead end with the much higher spark we get nowadays with electronic ignition etc.

not to mention individual coil packs...

Indexing washers come in 3 sizes you don't stack em. Hope Lauren spots this thread cos I'm sure she will have tried this.

Indexing Washers?

now that is a new one on me, never realised thats how they proposed to do it,


learn something new every day.


Dieing to know if its been proven worthwhile still though

Here's something on it

http://speedtalk.com/forum/viewtopic.php?t=5093

Indexing spark plugs does work,.. in fact Mercedes Benz do it even as we speak. Thats reason it is so important that you torque up spark plugs in current Mercedes engines, so you align to electrode and reveal the spark to the combustion charge. the spark plug thread is cut and the electrode positioned so that when its correctly tightened, it all lines up. its frankly scary how many techs i spoke to in my old job about this who did not know you had to do this.. i think the phrase is R.T.F.M. ( i used to be a technical trainer for a certain larger German car manufacturer that happens to have a 3 pointed star as its badge )

For spark plugs that are not thread aligned, you can get indexing rings of different thickness's. .. you mark the out side of the plug to show you where the earth electrode is, then tighten to the correct torque and see where you are.. the kits normally have a little chart that would show how thick a washer you needed for rotational degree change. Often american kits would quote thousands of an inch,. i always went with 40 thou = 1mm

I used to use golden lodge plugs as I did my apprenticeship with alfa romeo, and kind of grew up with them... one day when we could not get some. I thought go with the NGK and see what happens. It was like night and day. never used golden lodge since... I have also used the bosch super 4, they are pretty good too

just my 2 pence worth after 25 odd years of messing about with cars professionally and as a hobby
:O)

Hooray - I feel vindicated. Thanks.

Hey mate, no-one said its not a good idea, and this has certainly become a great thread too, so no need for vindication at all, I'm enjoying the flow of knowledge

Just debatable whether its worth doing, on a road car, under several hundred horsepower?

And i suspect that certain head design, with particular combustion shape, flame path etc would benefit more than others, especially with certain plug positions too.


Is it a practice reserved for the larger merc engines Kam, 500's and up, or do they factory fit aligned /indexed plugs to all petrol engines?

Don't laugh Shrew but I used to do this on a 600cc reliant trying to squeeze any bit of oomph out of it. Used to pop wheelies off the lights if I got it right.

Just to save any confusion, i take it you could pop a wheelie if you dropped the clutch at the sweet revs,


not "Crack a Vert" if you got your Champions lined up right!






and don't worry, no laughing at you owning a robin, I've had two!

Sud 145 wrote:Indexing washers come in 3 sizes you don't stack em. Hope Lauren spots this thread cos I'm sure she will have tried this.

Er... you reckon?

I've still got pink Lodge plugs in my engine, that's how much I know. And I'm still running points ignition on the standard engine, although the Alfatune has been set up for mapped ignition so will change over to that eventually.

As Shrew says, the theory seems fine in principle, but the benefit is likely to be too small to notice. It's the same argument as twin-plug heads, they made sense in 1968, now they are hopelessly outclassed by modern cylinder head design and EFI. But it is fun to drive past stranded Mercs and Beamers knowing that a quick wiggle of a connector is all that is necessary to get going again!

Lauren

Ooh you little rotter lauren! lol!

True enough though, but back to point, im keen to know more from kam on mercs practices on indexing,

Wheres he gone?

Im here shrew!

sorry i do tend to pop in and out of threads and forums in between work...

Yup mercedes v6 and v8, the 276 and 278 engines have indexed plugs, they need this when they run in stratified combustion mode, they also have a clever multi spark trick that sets up an arc over the plug gap rather than a single spark.

would you notice indexed plugs on a 30 year old alfa engine?? .. only way to know is to try it on an engine test bench...
but the original question about indexing is valid, it does work and it does happen

Also found this on the NGK site.. think they will know better than any body about spark plugs....
http://www.ngksparkplugs.com/tech_suppo ... p?mode=nml

petrolhead wrote:Just to save any confusion, i take it you could pop a wheelie if you dropped the clutch at the sweet revs,


not "Crack a Vert" if you got your Champions lined up right!






and don't worry, no laughing at you owning a robin, I've had two!

ROBIN, good grief nothing as new as that 2 Regal vans-as in Del Boy and a saloon.

Regals?


Sweet!