Spark Plug Gap?????? 40? 50? 60?
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From: Granby, MA
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Spark Plug Gap?????? 40? 50? 60?
Ok what is up with the spark plug gap for the LS1 engines. I have an 02 and right off of advance autoparts website lists like 3 different gaps for the same car! Depending on maker it can be .040, .050, or .060
A little advice here....I am going to go with the AC Delco Iridium's and they say, they come pre gapped at .040
Thanks Guys
Jeff
A little advice here....I am going to go with the AC Delco Iridium's and they say, they come pre gapped at .040
Thanks Guys
Jeff
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From: San Rafael CA
The AC Delco 49-145 Iridium plugs are CORRECTLY pre-gapped at .040 so check them, but they should all be fine.
The Irridium plugs use a smaller gap than the Platinum plugs did. They work great.
The Irridium plugs use a smaller gap than the Platinum plugs did. They work great.
Pro
Joined: Jun 2007
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From: Joppa AL
I recently put the iridium plugs in my 02 Coupe. Everyone here said they come gapped at 40, mine were 44 but I put them in and it runs great. Here's my question. I always thought the biggest gap the ignition system could handle was best. My old ones were 60 and the new ones 44. I can't tell any difference. Any ignition experts want to jump in here?
Melting Slicks
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From: Silver Spring MD
Iridiums are .040 but check them anyway
BIGHANK
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From: Vancouver Washington
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I put Iridium 41-985 plugs in my 2000 vett.
I don't know if the plugs are the same for the 02.
They do come pre-gapped at .040, but I have read they should be gapped at .042. Is this true?
I also put red performance wires in my. I am very happy. I did make a difference.
Good Luck
C T 00
I don't know if the plugs are the same for the 02.
They do come pre-gapped at .040, but I have read they should be gapped at .042. Is this true?
I also put red performance wires in my. I am very happy. I did make a difference.
Good Luck
C T 00
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The plug gap is determined more by coil output than anything else. If your ignition system can handle a larger gap and therefor put out a more robust spark, go for it. The coil will only put out enough spark to jump the gap, no more.
The LS1 ignition can handle a larger gap. The denso plugs I pulled had a gap of .060+. I put the AC iridium plugs in my 01 and opened the gap to .050. The car runs perfect.
The LS1 ignition can handle a larger gap. The denso plugs I pulled had a gap of .060+. I put the AC iridium plugs in my 01 and opened the gap to .050. The car runs perfect.
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From: San Rafael CA
The plug gap is determined more by coil output than anything else. If your ignition system can handle a larger gap and therefor put out a more robust spark, go for it. The coil will only put out enough spark to jump the gap, no more.
The LS1 ignition can handle a larger gap. The denso plugs I pulled had a gap of .060+. I put the AC iridium plugs in my 01 and opened the gap to .050. The car runs perfect.
The LS1 ignition can handle a larger gap. The denso plugs I pulled had a gap of .060+. I put the AC iridium plugs in my 01 and opened the gap to .050. The car runs perfect.
I recently put the iridium plugs in my 02 Coupe. Everyone here said they come gapped at 40, mine were 44 but I put them in and it runs great. Here's my question. I always thought the biggest gap the ignition system could handle was best. My old ones were 60 and the new ones 44. I can't tell any difference. Any ignition experts want to jump in here?
The larger the gap the higher the voltage needed to "jump" it ... which means the coil needs longer to generate the required power. If you had a 10 foot gap, you'd need to generate a thunderbolt to jump it ... by going with a smaller gap, the spark fires closer to the time the PCM requests it.
In the "old" days a larger gap meant a "better" (hotter) spark to light off the fuel/air mix. Today, engines run much "hotter" than before. The fuel is very close to lighting off even before the spark is fired. It doesn't take much to start the fuel burn, so a smaller gap is sufficient.
Pro
Joined: Jun 2007
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From: Joppa AL
I'm not an expert ... but I did stay at a Holiday Inn last night .... the gap is determined by several things .....
The larger the gap the higher the voltage needed to "jump" it ... which means the coil needs longer to generate the required power. If you had a 10 foot gap, you'd need to generate a thunderbolt to jump it ... by going with a smaller gap, the spark fires closer to the time the PCM requests it.
In the "old" days a larger gap meant a "better" (hotter) spark to light off the fuel/air mix. Today, engines run much "hotter" than before. The fuel is very close to lighting off even before the spark is fired. It doesn't take much to start the fuel burn, so a smaller gap is sufficient.
). Sometimes I keep my mind busy by dreaming up all kinds of weird questions about car stuff. Part of the problem is my experience is mostly with older vehicles. Do you remember magnetos in race cars?
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From: San Rafael CA
Thanks, BlackZ06. That explains a lot (I need to find one of those Holiday Inns ). Sometimes I keep my mind busy by dreaming up all kinds of weird questions about car stuff. Part of the problem is my experience is mostly with older vehicles. Do you remember magnetos in race cars?
). Sometimes I keep my mind busy by dreaming up all kinds of weird questions about car stuff. Part of the problem is my experience is mostly with older vehicles. Do you remember magnetos in race cars?
Instructor
Joined: Nov 2007
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From: Houston, Texas
Speaking of spark plugs, I removed one of my plugs for inspection this past weekend, as my car has some 59,000 miles on the clock. The wear appeared neglible but I noticed that the plug was non OEM. I purchased my '99 FRC in '01 with about 18,000 so, evidently, the previous owner changed the plugs.
Now the interesting part. The plugs are: NGK PTR5C-13. I have not seen this show up as a recommended plug? Is this perhaps an obsolete plug designation?
Thanks,
Jason
Now the interesting part. The plugs are: NGK PTR5C-13. I have not seen this show up as a recommended plug? Is this perhaps an obsolete plug designation?
Thanks,
Jason
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Joined: Jul 2004
Posts: 3,904
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From: Vancouver Washington
Speaking of spark plugs, I removed one of my plugs for inspection this past weekend, as my car has some 59,000 miles on the clock. The wear appeared neglible but I noticed that the plug was non OEM. I purchased my '99 FRC in '01 with about 18,000 so, evidently, the previous owner changed the plugs.
Now the interesting part. The plugs are: NGK PTR5C-13. I have not seen this show up as a recommended plug? Is this perhaps an obsolete plug designation?
Thanks,
Jason
Now the interesting part. The plugs are: NGK PTR5C-13. I have not seen this show up as a recommended plug? Is this perhaps an obsolete plug designation?
Thanks,
Jason
P = Premium Platinum
T = tapered seat
R = Resistor type
5 = heat range about the same as the TR55
C = Special design firing end
13= plug gap of .052
If it's not a recommended plug, it's sure close.
Le Mans Master
Joined: Jul 2005
Posts: 5,328
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Speaking of spark plugs, I removed one of my plugs for inspection this past weekend, as my car has some 59,000 miles on the clock. The wear appeared neglible but I noticed that the plug was non OEM. I purchased my '99 FRC in '01 with about 18,000 so, evidently, the previous owner changed the plugs.
Now the interesting part. The plugs are: NGK PTR5C-13. I have not seen this show up as a recommended plug? Is this perhaps an obsolete plug designation?
Thanks,
Jason
Now the interesting part. The plugs are: NGK PTR5C-13. I have not seen this show up as a recommended plug? Is this perhaps an obsolete plug designation?
Thanks,
Jason
http://forums.corvetteforum.com/show....php?t=1771192
He was the original owner of a '99 FRC and it had the NGK PTR5C-13 plugs in it, too.
I just changed the plugs/wires in my daughters' '99 coupe we bought in 2003 with 40K miles and they were...NGK PTR5C-13 spark plugs.
Obviously, GM used those plugs for OEM installation, I'm sure the previous owner didn't replace the plugs in your car or ours. Now for the best part, he had 110K miles on his plugs and we had 118K miles on ours and they still looked good...if I had known they were in such good shape, I would have left them alone until at least 150K miles maybe 200K. The original spark plug wires are the "spiral core" design with very low resistance and were also in excellent shape. As the miles pile up on this car, it's becoming more and more apparent that it's an easy 200K mile engine with only oil and filter (air and oil) changes. I change the oil strictly IAW the DIC and never before. Yours is still a baby at 59K miles.
PS Yes, we've had the harmonic balancer (once) and oil pressure switch (twice now as of last month) issues and I replaced the water pump and idler pulleys/tensioners last September. Only $400 in engine repairs in almost 120K miles is excellent as far as I'm concerned.
Last edited by glass slipper; Mar 3, 2008 at 11:59 PM.