spark plug gapping
Thread Starter
Racer
Joined: Dec 2003
Posts: 448
Likes: 1
From: Naples Fl
spark plug gapping
Ok how is every body keeping the gap square? By the time I get the huge .060 gap bent in the plug the electrode is at an angle and not paralell with the plug. My handy dandy snap on plug gap tool used to do it perfectly but it only goes up to .045, so I had to use the old style gapper. Does it really matter all that much anyway? The spark is going to go to the shortest distance right? I got the delco Irridium plugs and I am afraid to damage that tiney tip if I put a .060 feeler gauge and tap the electrode square to it. These cars must have a powerful ignition to fire a gap that size anyway. :steering:
Safety Car
Joined: Oct 2000
Posts: 4,949
Likes: 10
From: Monticello MN
Re: spark plug gapping (jl240z)
Ok how is every body keeping the gap square? By the time I get the huge .060 gap bent in the plug the electrode is at an angle and not paralell with the plug. My handy dandy snap on plug gap tool used to do it perfectly but it only goes up to .045, so I had to use the old style gapper. Does it really matter all that much anyway? The spark is going to go to the shortest distance right? I got the delco Irridium plugs and I am afraid to damage that tiney tip if I put a .060 feeler gauge and tap the electrode square to it. These cars must have a powerful ignition to fire a gap that size anyway. :steering:
Ed
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Re: spark plug gapping (C5XTASY)
I thought these plugs came pre-gapped.
Ed
Ed
I bought a set of NGK-55's. They were gapped @ .050, so I set them to .060. I have about 1500 miles on them with no problems. I found out later that they were pre-gapped to .050. I would guess at that gap you get the best spark with iridium on those plugs. All the info I have gotten regarding this is to leave them at .050.
Having said that, I don't know if the Delco's are pre-gapped, but if they are all .050 it seems obvious. I was going to take mine out and regap them back to .050 but several members here told me not to worry about it. I haven't and 1500 miles later all is still well and I'm still making good power and torque with no misfires. I hope someone with more knowledge of this than me could enlighten us both. :lurk:
[Modified by ArKay99, 12:49 PM 2/4/2004]
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Re: spark plug gapping (C5XTASY)
I thought these plugs came pre-gapped.
Ed
Ed
Having said that, I don't know if the Delco's are pre-gapped, but if they are all .050 it seems obvious. I was going to take mine out and regap them back to .050 but several members here told me not to worry about it. I haven't and 1500 miles later all is still well and I'm still making good power and torque with no misfires. I hope someone with more knowledge of this than me could enlighten us both. :lurk:
Thread Starter
Racer
Joined: Dec 2003
Posts: 448
Likes: 1
From: Naples Fl
Re: spark plug gapping (C5XTASY)
I thought so too. The gap looked large but when I checked they were at about .040-.045. Since the factory service manuel said .060 I opened them up some more. I dont think the manuel considered irridiums when it was written for the 2000 model. I think I will have gene at Fred Beans check into it just in case. I got the plugs from him and he is good about customer service. Ill post if the gap is less than .060. :steering:
Thread Starter
Racer
Joined: Dec 2003
Posts: 448
Likes: 1
From: Naples Fl
Re: spark plug gapping (MDT)
Mark that was my first impulse but on the back of the box it sez under the iridium plug description in bold letters "set gap per vehicle specifications" I was more than happy to follow the manual and the box but the results of bending electodes out to .060 just looks wrong somehow. Im going to wait for an answer from gene culley and then decide. Thanks for your input :steering:
Safety Car
Joined: Nov 2000
Posts: 4,419
Likes: 6
From: Arroyo Grande CA
Re: spark plug gapping (MDT)
jl240z,
The AC Delco 41-985 Iridium plugs come with a pre-gap of .040 in. and are to be run with that gap.
Mark
The AC Delco 41-985 Iridium plugs come with a pre-gap of .040 in. and are to be run with that gap.
Mark
The factory setting for the 2000 is for the original platinum plugs.
The AC-Delco site states to not deviate from the preset gap of .040" on the 41-985's.
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Melting Slicks
Joined: Aug 2000
Posts: 2,248
Likes: 1
From: Newland US
Re: spark plug gapping (2KFRC5)
jl240z,
Per GM bulletin (03-06-04-060) issued in October 03...the 41-985 Iridium plug is called out as the replacement plug in all C5's, '97-'04....LS1 and LS6. It is emphasized to NOT change the gap from the .040 in. preset.
Mark
Per GM bulletin (03-06-04-060) issued in October 03...the 41-985 Iridium plug is called out as the replacement plug in all C5's, '97-'04....LS1 and LS6. It is emphasized to NOT change the gap from the .040 in. preset.
Mark
Drifting
Joined: Sep 2001
Posts: 1,651
Likes: 0
From: Ocean County NJ
Re: spark plug gapping (MDT)
Per GM bulletin (03-06-04-060) issued in October 03...the 41-985 Iridium plug is called out as the replacement plug in all C5's, '97-'04....LS1 and LS6. It is emphasized to NOT change the gap from the .040 in. preset.
Mark [/QUOTE]
That is what I was told by C4C5specialist
Mark [/QUOTE]
That is what I was told by C4C5specialist
Racer
Joined: Aug 2003
Posts: 290
Likes: 8
From: 60 miles from BGKY
Re: spark plug gapping (skidmarc)
Then my feeler gauges must be toasted (I use two different ones for comparison). My Delco Iridiums were gapped wider than that out of the box, and I agree it is very misleading to have the box say 'gap to vehicle specs' while the web site says 'don't deviate'. I read other threads where it was stated gap should be in the mid 50's. I seem to be doing OK with them there. AutoTap numbers look fine.
Le Mans Master
Joined: Oct 2000
Posts: 6,509
Likes: 726
From: Sausalito CA
Re: spark plug gapping (jl240z)
A high quality plug gapping tool is preferred.
However, those $1 round ones from pep boys do work to get one in the ball park.
Also, as plugs wear, the gap increases.
So I question whether .60 is a new plug or a 30K mileage plug. Personally, I go to .55 based on the sentence above.
As for the TSB and .40, that reads to me to mean the setting at new plugs.
However, those $1 round ones from pep boys do work to get one in the ball park.
Also, as plugs wear, the gap increases.
So I question whether .60 is a new plug or a 30K mileage plug. Personally, I go to .55 based on the sentence above.
As for the TSB and .40, that reads to me to mean the setting at new plugs.
Thread Starter
Racer
Joined: Dec 2003
Posts: 448
Likes: 1
From: Naples Fl
Re: spark plug gapping (MDT)
You guys are right, with confirmation of .040 from the vendor and the GM service bulletin info, I will returning the gap to the preset. I am glad I looked here before I put them in with the .060 gap :yesnod: You gotta love this site. At least now I can use my handy dandy snap on gap tool :hurray: Thanks again to all :thumbs:
