Indexed Sparkplugs -- Note...Difference In Plugs

[oldguysrt10]

Some time in the past there was a thread indicating a possible performance improvement from indexing plugs due to the design of our combustion chamber. Seemed reasonable to me so I bought 20 new plugs per suggestion on the thread and went at it. Having learned on my Hemi that more expensive on plugs wasn't necessarily an improvement, I stayed with regular class plugs and bought NGK ZFR6F-11G V-Power plugs. After installation I compared the spare new plugs to the old (Champion RC12ECC) OEM plugs. The thread length of both plugs was identical but the ceramic part of the plug that extends into the cylinder was ca. 3/16" longer on the Champion than on the NGKs. I ran about 8,000 miles on the NGKs, couldn't get comfortable with the shorter electrode, (assumed DC had a reason for how the OEM plugs were configured, concerned about the spark not being as deep into the cylinder, and concerned about the reduced mass/minimal compression ratio reduction in the combustion chamber) so I bought 20 new OEM plugs and indexed/installed them yesterday. May just be my imagination but it seems to start just a little quicker now, and have a tighter/smoother idle.

Primary reason for the post is just to say there are some surprising (electrode length this time) differences in plugs that I would have assumed to be identical excepting a v-groove on the NGKs.

Yep, probably being anal but little things sometime add up and make a difference.

oldguy

 

[TNVIPER]

I am not sure what you mean by "indexing"?....is this why you buy the extra 10 plugs?..:dontknow:

 

[Blaine@PSI]

indexing the plugs was an OLD cirlce track trick that WORKED and a N/A car would usually pick up around 10-15hp which was great due to the constraints of the rules. Anyway what you doing indexing the electrode to point direct at the exhaust valve to insure quicker faster burn. results are free hp.

 

[TNVIPER]

indexing the plugs was an OLD cirlce track trick that WORKED and a N/A car would usually pick up around 10-15hp which was great due to the constraints of the rules. Anyway what you doing indexing the electrode to point direct at the intake valve to insure quicker faster burn. results are free hp.

Now it comes back..I remember that from many moons ago..thanks..

 

[JRSVIPR]

indexing the plugs was an OLD cirlce track trick that WORKED and a N/A car would usually pick up around 10-15hp which was great due to the constraints of the rules. Anyway what you doing indexing the electrode to point direct at the intake valve to insure quicker faster burn. results are free hp.

So would that be, Electrode pointing to 12:00 or? I'm a dumbass.

 

[Blaine@PSI]

Now it comes back..I remember that from many moons ago..thanks..

No problem my dad taught me those tricks not so long ago as I am just a wee one young wippersnapper.

 

[Blaine@PSI]

So would that be, Electrode pointing to 12:00 or? I'm a dumbass.

well idealy you want it to point at the center of the combustion chamber and just using the exhaust or intake valve as reference. If it is pointed at the chamber wall then you can see the ill effects it can have.

 

[JRSVIPR]

well idealy you want it to point at the center of the combustion chamber and just using the exhaust or intake valve as reference. If it is pointed at the chamber wall then you can see the ill effects it can have.

Thanks.:dontknow:

 

[Black1]

I used to do this in my go-karts. :rock:

Great idea, guys! :burnout:

 

[rottenronnie]

Some time in the past there was a thread indicating a possible performance improvement from indexing plugs due to the design of our combustion chamber. Seemed reasonable to me so I bought 20 new plugs per suggestion on the thread and went at it. Having learned on my Hemi that more expensive on plugs wasn't necessarily an improvement, I stayed with regular class plugs and bought NGK ZFR6F-11G V-Power plugs. After installation I compared the spare new plugs to the old (Champion RC12ECC) OEM plugs. The thread length of both plugs was identical but the ceramic part of the plug that extends into the cylinder was ca. 3/16" longer on the Champion than on the NGKs. I ran about 8,000 miles on the NGKs, couldn't get comfortable with the shorter electrode, (assumed DC had a reason for how the OEM plugs were configured, concerned about the spark not being as deep into the cylinder, and concerned about the reduced mass/minimal compression ratio reduction in the combustion chamber) so I bought 20 new OEM plugs and indexed/installed them yesterday. May just be my imagination but it seems to start just a little quicker now, and have a tighter/smoother idle.

Primary reason for the post is just to say there are some surprising (electrode length this time) differences in plugs that I would have assumed to be identical excepting a v-groove on the NGKs.

Yep, probably being anal but little things sometime add up and make a difference.

oldguy

Yup, that was my thread.
Indexing works more on some engines than others. For example the old 426 Hemis ignored indexing (for obvious reasons). I don't know if the Strikers will benefit from indexing.
I will continue to index plugs on the o.e.m. heads. You can look at the porcelain on the "far side" of a plug pulled from our engines and see how it is masked from combustion by looking at the burn shadow..
Hell, if the guys running NASCAR and other high end racing divisions pay attention to the really little stuff, who am I to argue?

 

[rottenronnie]

I am not sure what you mean by "indexing"?....is this why you buy the extra 10 plugs?..:dontknow:

The plugs all have threads that "start" in a different location, Buy purchasing more than you need, your chances improve when indexing.
Some used to use washers to accomplish the same thing. (DON'T).

 

[TNVIPER]

The plugs all have threads that "start" in a different location, Buy purchasing more than you need, your chances improve when indexing.
Some used to use washers to accomplish the same thing. (DON'T).

Thanks.....

 

[oldguysrt10]

I bought 20 OEM plus had 10 of the original OEM that had less than 5,000 miles on them. From the picture posted on the original thread about indexing, appears there was a dead spot pertinent to electrode location on the top side of the head between the valves. I aligned the opening on the electrode pretty much center of the intake valve on all cylinders. I marked a line up the side of the socket and extension and inserted the plug so the electrode lined up with the line. Consistent with the instructions with the plugs I tightened each plug 1/2 turn after making contact to compress the new metal gasket. So, when contact was made 180^ out from where I wanted the electrode to be, I just tightened 1/2 turn more. On a couple of cylinders I got a plug that worked by the 2nd and 3rd try. On a couple of cylinders though I got the position I needed on plug 12 and 15. Considering how cheap plugs are and my time being free, seemed worth the effort to gain a few free hosepower.

oldguy

 

[rottenronnie]

I bought 20 OEM plus had 10 of the original OEM that had less than 5,000 miles on them. From the picture posted on the original thread about indexing, appears there was a dead spot pertinent to electrode location on the top side of the head between the valves. I aligned the opening on the electrode pretty much center of the intake valve on all cylinders. I marked a line up the side of the socket and extension and inserted the plug so the electrode lined up with the line. Consistent with the instructions with the plugs I tightened each plug 1/2 turn after making contact to compress the new metal gasket. So, when contact was made 180^ out from where I wanted the electrode to be, I just tightened 1/2 turn more. On a couple of cylinders I got a plug that worked by the 2nd and 3rd try. On a couple of cylinders though I got the position I needed on plug 12 and 15. Considering how cheap plugs are and my time being free, seemed worth the effort to gain a few free hosepower.

oldguy

Are you at or near sea level?

 

[SANCHOBA]

good idea! how about a simple diagram to show where the valves are located? and where you would align the electrode.

 

[oldguysrt10]

Are you at or near sea level?

Yep, I live in Orange, Texas. Tracks I run at are Houston Raceway Park and Ben Bruce Memorial (Evadale). Both are near sea level, and I only go to the track when conditions are optimum for a new best time. It's not uncommon to go just after a cold front pushes through and get a very good and sometimes even a negative DA. My best run/12.8201 / 108.75mph was at Ben Bruce with air temp at 67^ but with a 17mph tailwind out of the North. We have a prevailing South wind in our area (ca. 70% of the time) and Ben Bruce was once an airport with the track running North to South for landing into the wind. My best at HRP was a 12.830 / 107.5mph into a 7mph headwind (track runs South to North) but with a negative DA and an air temp of 47^.

oldguy

 

[rottenronnie]

Yep, I live in Orange, Texas. Tracks I run at are Houston Raceway Park and Ben Bruce Memorial (Evadale). Both are near sea level, and I only go to the track when conditions are optimum for a new best time. It's not uncommon to go just after a cold front pushes through and get a very good and sometimes even a negative DA. My best run/12.8201 / 108.75mph was at Ben Bruce with air temp at 67^ but with a 17mph tailwind out of the North. We have a prevailing South wind in our area (ca. 70% of the time) and Ben Bruce was once an airport with the track running North to South for landing into the wind. My best at HRP was a 12.830 / 107.5mph into a 7mph headwind (track runs South to North) but with a negative DA and an air temp of 47^.

oldguy

I have a QC as well.
These trucks are quite sensitive to good air/bad air and temperature. It would be VERY tough (impossible?) with my QC without some substantial mods to run the MPH range you are in, at our local track.
I am going to a low level track in a couple of weeks and should run 106+ with the current mods I have. Then next year with mods...we will see...
Our trucks share aerodynamics with most apartment buildings; and even a bit of a headwind can really make them struggle.

 

[oldguysrt10]

I have a QC as well.
These trucks are quite sensitive to good air/bad air and temperature. It would be VERY tough (impossible?) with my QC without some substantial mods to run the MPH range you are in, at our local track.
I am going to a low level track in a couple of weeks and should run 106+ with the current mods I have. Then next year with mods...we will see...
Our trucks share aerodynamics with most apartment buildings; and even a bit of a headwind can really make them struggle.

Best of luck when you head to the track. I plan to head to HRP whatever first Friday night the temp. dips below 60^...probably October. Since last season I've added a JMB CAI, picked up some drag radials/lighter rims, and am getting bands on my tranny adjusted next week and a shift kit installed. I'm hopeful for a lower time this season. Absolutely no doubt I benefit most from having a track near sea level. Seems the normally aspirated vehicles are affected more by air temp. and barometric pressure than those with forced induction. No doubt they're affected also, just doesn't seem to result in nearly as big of swings in their times.

Again, best of luck.

oldguy

 

[rottenronnie]

Best of luck when you head to the track. I plan to head to HRP whatever first Friday night the temp. dips below 60^...probably October. Since last season I've added a JMB CAI, picked up some drag radials/lighter rims, and am getting bands on my tranny adjusted next week and a shift kit installed. I'm hopeful for a lower time this season. Absolutely no doubt I benefit most from having a track near sea level. Seems the normally aspirated vehicles are affected more by air temp. and barometric pressure than those with forced induction. No doubt they're affected also, just doesn't seem to result in nearly as big of swings in their times.

Again, best of luck.

oldguy

The forced induction guys are affected but like you say, not like we are. As an average, dropping from our altitude to sea level provides a 10% gain. So, in my case 50 horsepower. It is like adding a 2 p.s.i. supercharger.

Good luck to you as well, and have fun!

 

[rottenronnie]

good idea! how about a simple diagram to show where the valves are located? and where you would align the electrode.

Point the electrode somewhere between 10 and 2 o'clock. Not between 8 and 4.
My apologies if you are young and only understand digital time.
Good photos of our heads at:
http://www.performancecylinderheads.com/Viperpage.htm