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We have a picture and a video from credible sources (Eli and Peter) that show what several ICN members believe to be the correct orientation of the spark plug electrode/gap when installed into the cylinder head.



(rotated screen capture from peter's video in http://www.insightcentral.net/forums/problems-troubleshooting/18738-new-spark-plug-indexing-7.html#post230214



Based on the designation of the non-VTEC and VTEC-E valves from above, the valves are therefore labeled:



This matches your labeling of the valves.



With the valves labeled this way, it appears the properly torqued spark plugs have their gaps facing the VTEC-E valve, contrary to what several others believe to be the correct orientation, that being the gap facing the non-VTEC valve.

Anyone want to work through this (again) and see if I missed something? Is it just the semantics of designating the valves?
 

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I've more or less just repeated what others have most strongly asserted about which valve was the non-vtec and where the open side of the electrode is supposed to face. So it looks like the non-vtec valve is actually what INO and davenm describe above, and it seems probable that the open side of the electrode does face the vtec valve... I was thinking 'why?' and started thinking that maybe the swirl of the charge and the timing of 'it all' makes it better to place the most unobstructed spark toward the vtec valve, but maybe more simply, just in that area, kind of like ignition timing and spark advance... I then looked for an image of 'the swirl' and found this page: Honda Worldwide | CIVIC Hybrid

Not 100% support but a little more info nevertheless. Here's the 'swirl' image:

Maybe someone else can put it all together...

Here's another image of the swirl for vtec-e, 4 valves:

Perbezaan1

Here's some of the exact text on vtec-e from the above webpage:
A novel implementation of VTEC in SOHC engines is the VTEC-E implementation (E for Economy). VTEC-E uses the principle of swirling to promote more efficient air-and-fuel mixing in the engine chambers. VTEC-E works by deactivating one intake valve. Examine the diagram below [above].
In the SOHC VTEC-E implementation, only one intake cam-lobe is implemented on the camshaft. Actually it is really a flat "ring". In operation this means the relevant rocker arm will not be activated causing the engine to effectively work in 12-valve mode. This promotes a swirl action during the intake cycle. VTEC is used to activate the inactive valve, making the engine work in 16-valve mode in more demanding and higher rpm conditions. Honda was able to implement air-fuel mixture ratios of more than 20:1 in VTEC-E during the 12-valve operating mode.


So, if I'm understanding this correctly, the left valve in the diagram above is the non-vtec valve and operates always, the right is the vtec valve and operates only in vtec mode, and the open end of the spark plug electrode faces 'away' from our viewing angle, roughly 270 degrees from where the air-fuel mixture enters the combustion chamber. Now what would help is something telling us why that general area/location is best, like a diagram showing the richness of the mixture in different parts of the combustion chamber...
 

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spark plugs

In the end of it all lets remember that the engineers that designed this car were at the high-end works in Japan . That being said there was a reason for indexed spark plugs. Any perceived saving is to me a waste of energy/brain cells and money.Now if a Honda Japan factory engineering said you can use mars unobtainum plugs then there might be some credibility until then spend the money and get the right plugs. Great reading though.
 

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Plug Qs

That diagram does not show and is not meant to show the plugs as they are in the cylinder head when properly indexed. It's just an exploded view.

This is what properly indexed plugs look like from the combustion chamber side:



Again, the open end of the electrode needs to face the non-VTEC intake valve.

I'm installing plugs for the first time in my 2002 Insight and wouls like to know a few things.
First what is A B C D ect mean in terms of spark plugs? and what brand is best for best results?
how do I index the plugs in relation to the Non V TEC intake vales?

Thank you in Advance :)
 

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^That encyclopedia article is a little 'thin'...

how do I index the plugs in relation to the Non V TEC intake vales?
The quick answer is that you buy the NGK plugs with the same indexing letter on them as what's stamped into your cylinder head. They'll all be either A, B, C, or D, most commonly B. Then when you torque them to spec they should clock correctly in the spark plug bore...

The correct 'clocking' is with the open side of the ground electrode facing the secondary valve, the VTEC valve - or roughly in that vicinity.

Insightgeo in a recent post* incorrectly interprets a Honda article that states that the closed-side of the electrode shouldn't block the primary intake valve - Insightgeo misinterprets this to mean that the open side should face the primary intake valve (having the 'closed side not blocking' and having the 'open side facing' are two different things). The sleuthing in older posts above show that the open side faces the VTEC valve. How exact this needs to be who knows... It's just what the evidence shows...

*https://www.insightcentral.net/forums/problems-troubleshooting/123539-location-spark-plug-index-letters.html#post1427703

With the open side facing the VTEC valve, the closed side isn't blocking the primary intake valve, so that fits with the Honda article. Beyond that I guess it's more important to have the open side facing the VTEC valve for its intermittent operation, to help with power, better combustion during VTEC mode, etc., rather than having the open side facing the primary intake valve during constant, normal operation...

When you look at that 'swirl' diagram above, it's plausible to think that the air-fuel mixture will be richest around the arrow diagram, that is, the side opposite from where air intake starts - which is where the open side of the spark plug electrode would be located if it were facing the VTEC valve. That's normal operation or lean burn operation. But, when the VTEC valve opens, air will be pulled into the combustion chamber from that valve and disrupt the 'swirl' - and then the open side of the spark plug - the spark - is right there in its path... Maybe that part doesn't matter too much, since the air-fuel mixture is stoichiometric at this point. The more important part, I think, is the swirl, where the richest mixture is during single valve operation...
 
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