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1989 Civic DX
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418 Posts
Discussion Starter #1
Materials Required:



Spark plugs of choice, NGK BCPR6E-11 or Denso PQ20TT for the D16A6 pictured here, anti-seize lubricant and dielectric grease. It is very common to go through 2, 3, or even 4 sets of spark plugs to get the right position on all cylinders.


Tools Required:



Speeder wrench, spark plug socket.


Procedure:

1. Open the hood, and carefully remove one spark plug wire one at a time. Remove the old spark plug and place the new spark plug in the socket situated where the opening of the spark plug gap is pointing towards the elbow bend in the speeder wrench.



2. Apply a small amount of anti-seize to the threads of the spark plug and insert it into the head. Turn the wrench counter-clockwise until you hear/feel a 'click'. This insures proper threading of the spark plug into the cylinder head.



3. Now, turn the wrench clockwise until the crush washer has been crushed. The first two pictures are acceptable positions for the spark plug while the last is the preferred position.





If the spark plug is pointed in any other direction don't use it for that cylinder. Get another one and repeat steps 2 and 3. Apply dielectric grease to the spark plug wire boot before re-installing.

Rinse and repeat.
 

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90 CRX Si
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3,866 Posts
Nice, may have to try this...BTW have you ran those Denso TT plugs? I work at an advance and keep wanting to try them, I just don't have a need to right now.
 

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1989 Civic DX
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418 Posts
Discussion Starter #3
Nice, may have to try this...BTW have you ran those Denso TT plugs? I work at an advance and keep wanting to try them, I just don't have a need to right now.
Not just yet. I have the V-Power plugs in there now. I'm waiting to install the Denso plugs after my manifold/throttle body swap.

For $1.99 ea. I had to try them.
 

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94 civic si
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613 Posts
Cool I'll have to try this!

BTW that poster in your avatar is badass.

Not just yet. I have the V-Power plugs in there now. I'm waiting to install the Denso plugs after my manifold/throttle body swap.

For $1.99 ea. I had to try them.
 

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1989 Civic DX
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418 Posts
Discussion Starter #8
Cool I'll have to try this!

BTW that poster in your avatar is badass.
No poster, graffiti.

Good write-up.

However, why do you have the gap facing the intake valves?
The theory is to "aim" the ignition spark towards the fuel and air mixture for a cleaner, smoother burn.

There are other things that are done to spark plugs in order to optimize the spark for a specific setup, like gapping and side gapping. There have been a few pioneers that have drilled their plugs also.. this I'm not too familiar with so I won't endorse it.
 

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my name says Guest, but Im really a MEMBER
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10,488 Posts
actually, its not facing the air fuel mixture when its time to burn the mixture. The spark doesn't fire when the valve is open and the mixture is coming in. it ignites as its being compressed into the combustion chamber where the ground electrode is always going to have ................


The whole 360 degree circumfrence of the combustion chamber is where the fuel and air is. the spark plug is always going to be facing the air fuel mixture.


I really don't see it helping a pentroof design like are honda's have much. maybe on a wedge head design or other 2 valve combustion chamber designs.
 

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The theory is to "aim" the ignition spark towards the fuel and air mixture for a cleaner, smoother burn.
actually, its not facing the air fuel mixture when its time to burn the mixture. The spark doesn't fire when the valve is open and the mixture is coming in. it ignites as its being compressed into the combustion chamber where the ground electrode is always going to have ................


The whole 360 degree circumfrence of the combustion chamber is where the fuel and air is. the spark plug is always going to be facing the air fuel mixture.


I really don't see it helping a pentroof design like are honda's have much. maybe on a wedge head design or other 2 valve combustion chamber designs.
Yep, Guest nailed it. If anything, I would aim the gap toward the exhaust valves, since they can transfer more heat energy to the mixture, which might increase initial flame speed/propagation.
 

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Brokedick Millionaire
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40,579 Posts
enjoy your .5 whp for nothing.......

but then again I sorta killed this myth years ago.
 

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1989 Civic DX
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418 Posts
Discussion Starter #13
actually, its not facing the air fuel mixture when its time to burn the mixture. The spark doesn't fire when the valve is open and the mixture is coming in. it ignites as its being compressed into the combustion chamber where the ground electrode is always going to have ................


The whole 360 degree circumfrence of the combustion chamber is where the fuel and air is. the spark plug is always going to be facing the air fuel mixture.


I really don't see it helping a pentroof design like are honda's have much. maybe on a wedge head design or other 2 valve combustion chamber designs.
That was the same thing I was thinking.. so why does this still work?

Why is there a power increase when "aiming" the spark towards the intake?

I've always noticed a difference, the dyno noticed the difference.. I guess some people are going to do this and some aren't.

That' cool with me.
 

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3,452 Posts
post the before/after dyno sheets
Also, what engine was used, and how were the plugs originally aligned?

If the gain was under 1/2 hp, it's more likely due to the quantization error and instrument resolution/accuracy than the spark plug indexing.
 

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I also agree that spark plug indexing won't do much benefit, if any.

I also believed that spark plug indexing was for race engines with huge compression pistons for clearance purposes.
In our engines I see almost no point of directing the electrode to a fully functioning 360 degree chamber.
Aiming the Intake ports for what? coz when the piston compress the mixture the chamber is pregnate with the mixture.

ELECTRICITY doesn't matter where the intake and exhaust are.
 

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waste of money in a dd car. this is shit thats used in KART racing and other small engine vehicles where half a hp does somthing.

but good write up, its an oldy.
 

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MuthaFuckaUppa
2009 Civic Si Sedan
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571 Posts
i always set mine so the opening on the plug faces the exhaust valves. But that makes perfect sense, by the time the ignition fires the intake valves are already closed.
i feel stupid for aligning my plugs now.
dynos can easily vary a 1/2 hp or more between runs even if you try to make everything perfect.
 

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Brokedick Millionaire
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40,579 Posts
1% error on dynos was the norm, that is about 1.0-.15 whp for use. Now down to about .5% error.

INDEXing plugs on a V8 with the plugs coming in at an angle is a good idea, but also gives more clearance of the ground strap to piston top. Nothing like hitting 7500 rpms and a stretching rod shuts the ground strap down killing spark in one cylinder.

With our near center placement of spark plugs, it is of little issue.
 

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Thanks for all your replies and supporting remarks. I was ready to go pop the hood on my car until I read what you guys were saying. You have the background info to support your remarks. I love it!

Peter
 
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