Spark Plug Question
Thread Starter
Melting Slicks
Joined: Apr 2005
Posts: 2,777
Likes: 105
Spark Plug Question
I have read a lot of good things concerning the NGK Iridium spark plugs in performance engines. Many are running them is race motors....Has anyone used them in a high performance Big Block? And with MSD Ignition? 
Thread Starter
Melting Slicks
Joined: Apr 2005
Posts: 2,777
Likes: 105
Its funny - I just installed a set of these in my highly modified BB and it idles a bit higher and smoother.
The acceleration and overall performance is actually better.....Im also running MSD Ignition.
Maybe I'm crazy but this is the best this motor has run in decades!
The acceleration and overall performance is actually better.....Im also running MSD Ignition.
Maybe I'm crazy but this is the best this motor has run in decades!
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
If your car runs a bit better, it's likely not the spark plug design that caused it. It's probably due to the plugs being new and gapped properly compared to the old plugs. In my '69 L71 I have AC Rapid Fire plugs with the gap opened a bit for the MSD 6A. It starts a bit easier and gets slightly better gas mileage (still bad w/4.11 gears), but I ascribe that to the MSD and maybe the bigger plug gap for more complete combustion.
I found out several years back that you really don't need the exotic spark plugs unless that's what the car manufacturer calls for. Maybe the more expensive plugs might last longer, which means the car may maintain its level of performance longer before replacements are necessary. I once tried one of the more expensive spark plugs...SplitFire. The car ran no different and within a few months, two of them cracked their ceramics. I replaced them with oe plugs and the car ran just as fine and no problems.
I've just come to believe if you buy whatever spark plug you like, in the correct heat range and gap it properly, and maintain the entire ignition system properly, your car should run optimally. It's no better than its weakest link.
I found out several years back that you really don't need the exotic spark plugs unless that's what the car manufacturer calls for. Maybe the more expensive plugs might last longer, which means the car may maintain its level of performance longer before replacements are necessary. I once tried one of the more expensive spark plugs...SplitFire. The car ran no different and within a few months, two of them cracked their ceramics. I replaced them with oe plugs and the car ran just as fine and no problems.
I've just come to believe if you buy whatever spark plug you like, in the correct heat range and gap it properly, and maintain the entire ignition system properly, your car should run optimally. It's no better than its weakest link.
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
If your car runs a bit better, it's likely not the spark plug design that caused it. It's probably due to the plugs being new and gapped properly compared to the old plugs. In my '69 L71 I have AC Rapid Fire plugs with the gap opened a bit for the MSD 6A. It starts a bit easier and gets slightly better gas mileage (still bad w/4.11 gears), but I ascribe that to the MSD and maybe the bigger plug gap for more complete combustion.
I found out several years back that you really don't need the exotic spark plugs unless that's what the car manufacturer calls for. Maybe the more expensive plugs might last longer, which means the car may maintain its level of performance longer before replacements are necessary. I once tried one of the more expensive spark plugs...SplitFire. The car ran no different and within a few months, two of them cracked their ceramics. I replaced them with oe plugs and the car ran just as fine and no problems.
I've just come to believe if you buy whatever spark plug you like, in the correct heat range and gap it properly, and maintain the entire ignition system properly, your car should run optimally. It's no better than its weakest link.
I found out several years back that you really don't need the exotic spark plugs unless that's what the car manufacturer calls for. Maybe the more expensive plugs might last longer, which means the car may maintain its level of performance longer before replacements are necessary. I once tried one of the more expensive spark plugs...SplitFire. The car ran no different and within a few months, two of them cracked their ceramics. I replaced them with oe plugs and the car ran just as fine and no problems.
I've just come to believe if you buy whatever spark plug you like, in the correct heat range and gap it properly, and maintain the entire ignition system properly, your car should run optimally. It's no better than its weakest link.
Couldn't agree more! 
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
If your car runs a bit better, it's likely not the spark plug design that caused it. It's probably due to the plugs being new and gapped properly compared to the old plugs. In my '69 L71 I have AC Rapid Fire plugs with the gap opened a bit for the MSD 6A. It starts a bit easier and gets slightly better gas mileage (still bad w/4.11 gears), but I ascribe that to the MSD and maybe the bigger plug gap for more complete combustion.
I found out several years back that you really don't need the exotic spark plugs unless that's what the car manufacturer calls for. Maybe the more expensive plugs might last longer, which means the car may maintain its level of performance longer before replacements are necessary.
I found out several years back that you really don't need the exotic spark plugs unless that's what the car manufacturer calls for. Maybe the more expensive plugs might last longer, which means the car may maintain its level of performance longer before replacements are necessary.
I too am using the MSD HEI ignition system (used the same MSD for both plugs).
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
I disagree.. I replaced my new stock AC Delco's with NGK Iridiums in my 75 new crate engine and my car runs MUCH, MUCH better....idle, pick up, gas mileage...just over all performance...I can definitely feel the difference!!! I too am using the MSD HEI ignition system (used the same MSD for both plugs).
I too am using the MSD HEI ignition system (used the same MSD for both plugs).
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Pro
Joined: Jan 2006
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From: New York
....I don't know about his case but I do believe we are conned bigtime into buying what Madison ave. tells us we should use.......By the way I use Bosch for my BB........Jerrylee///
Thread Starter
Melting Slicks
Joined: Apr 2005
Posts: 2,777
Likes: 105
I disagree.. I replaced my new stock AC Delco's with NGK Iridium's in my 75 new crate engine and my car runs MUCH, MUCH better....idle, pick up, gas mileage...just over all performance...I can definitely feel the difference!!! I too am using the MSD HEI ignition system (used the same MSD for both plugs).
I too am using the MSD HEI ignition system (used the same MSD for both plugs).Roughrider - The regular NGK's I pulled out had 70 miles on them and were gaped exactly the same as the new Iridiums, so your assumption regarding old plugs and plug gaps is not valid.
The heat tolerance of the Iridium electrode is far better than any other plug out there, read the specs.
All I can say is, try em, you'll like em......
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Its Your Money,
If your car runs a bit better, it's likely not the spark plug design that caused it. It's probably due to the plugs being new and gapped properly compared to the old plugs. In my '69 L71 I have AC Rapid Fire plugs with the gap opened a bit for the MSD 6A. It starts a bit easier and gets slightly better gas mileage (still bad w/4.11 gears), but I ascribe that to the MSD and maybe the bigger plug gap for more complete combustion.
I found out several years back that you really don't need the exotic spark plugs unless that's what the car manufacturer calls for. Maybe the more expensive plugs might last longer, which means the car may maintain its level of performance longer before replacements are necessary. I once tried one of the more expensive spark plugs...SplitFire. The car ran no different and within a few months, two of them cracked their ceramics. I replaced them with oe plugs and the car ran just as fine and no problems.
I've just come to believe if you buy whatever spark plug you like, in the correct heat range and gap it properly, and maintain the entire ignition system properly, your car should run optimally. It's no better than its weakest link.
I found out several years back that you really don't need the exotic spark plugs unless that's what the car manufacturer calls for. Maybe the more expensive plugs might last longer, which means the car may maintain its level of performance longer before replacements are necessary. I once tried one of the more expensive spark plugs...SplitFire. The car ran no different and within a few months, two of them cracked their ceramics. I replaced them with oe plugs and the car ran just as fine and no problems.
I've just come to believe if you buy whatever spark plug you like, in the correct heat range and gap it properly, and maintain the entire ignition system properly, your car should run optimally. It's no better than its weakest link.
One can disagree all they want, it`s their money. But all thats necessary is in this statement. I also had both Autolite and Champion racing division confide to me that there all the same, some just cost more than others. BTW, both companies provided me with spark plugs no charge .
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
vetteguy75 - Thank you for backing me up here.....I see the same difference. I'm running the original 11:1 compression with aluminum, L88 closed chamber heads, a cam that has 262@.050 duration, modified tri-power carbs (550 CFM 4412 in the middle) amongst many other tweaks and ther is a remarkable difference in performance with the NGK Iridium plugs. I've owned my car since new so I can tell the difference, I have tried them all. Overall NGK's have worked the best for me.
Roughrider - The regular NGK's I pulled out had 70 miles on them and were gaped exactly the same as the new Iridiums, so your assumption regarding old plugs and plug gaps is not valid.
The heat tolerance of the Iridium electrode is far better than any other plug out there, read the specs.
All I can say is, try em, you'll like em......
Roughrider - The regular NGK's I pulled out had 70 miles on them and were gaped exactly the same as the new Iridiums, so your assumption regarding old plugs and plug gaps is not valid.
The heat tolerance of the Iridium electrode is far better than any other plug out there, read the specs.
All I can say is, try em, you'll like em......
Racer
Joined: Jan 2008
Posts: 291
Likes: 15
From: Virginia Beach VA
I also use and like NGK's... is there really that much of a price difference? I haven't run the numbers but I don't remember feeling like I was paying more for them than say Autolite or Bosch... NGK also has a very informative website and when I asked them for a plug recommendation they got back to me within a few hours with a plug and explanation...
And yes their marketing worked on me as well with their whole "V-power" thing... even if I know the spark will take the path of least resistance... lol... it just sounds cool.
And yes their marketing worked on me as well with their whole "V-power" thing... even if I know the spark will take the path of least resistance... lol... it just sounds cool.
Thread Starter
Melting Slicks
Joined: Apr 2005
Posts: 2,777
Likes: 105
I also use and like NGK's... is there really that much of a price difference? I haven't run the numbers but I don't remember feeling like I was paying more for them than say Autolite or Bosch... NGK also has a very informative website and when I asked them for a plug recommendation they got back to me within a few hours with a plug and explanation...
And yes their marketing worked on me as well with their whole "V-power" thing... even if I know the spark will take the path of least resistance... lol... it just sounds cool.
And yes their marketing worked on me as well with their whole "V-power" thing... even if I know the spark will take the path of least resistance... lol... it just sounds cool.
As far as the cost of the NGK V power plugs they go for around$2.49 each. The Iridium IX's (top of the NGK line) go for $8-$9 each.
