Home » Public Forums » GMCnet » [GMCnet] spark plug questions, please
| [GMCnet] spark plug questions, please [message #133508] |
Wed, 06 July 2011 12:56  |
Ek_Lektro
Messages: 167
Registered: March 2011
Karma: 2
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Senior Member |
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Well, its been a while.... and its definitely time for a new set of plugs!
not sure which ones to buy...
When i pulled a few of the old ones out, the gaps on them ranged from .45 to .70...
no wonder it was running crappy? (Can the gap change that much over time?
or is it more likely that the previous mechanic botched the gapping job?)
So i checked the cross reference on my GMC Motorhome International Parts Interchange Index (circa 1998!)
and for my '76 455, these are all listed as compatible:
AC R46SX with .80 gap
Bosch WR10FCZ with .80 gap
Champion RJ18YC6 with .60 gap
AutoLite 847 with no gap spec listed
in this same index, i can see that for other GMC years, the recommended gap can range from .40 to .80...
Considering that this '76 engine was supposedly rebuilt back in 2002,
is it safe to assume that they rebuilt the same engine, and that the same spark plug specs apply?
Bottom line, what's the conventional wisdom say about best plugs to use,
(and/or which to avoid), and of course, the recommended gap spec?
OK, thanks much for any info....
Greg
SolarSonic / LosAngeles
PS: No surprise, I've noticed that some of the parts numbers in this '98 index are starting to become obsolete
at AutoZone, etc. Wondering if this is mainly due to the parts in general getting more scarce over the years,
or if perhaps its just time for a new Parts Interchange Index?
Anybody know if GMCMHI has been keeping the parts index up to date?
If so, i think it'd be time to subscribe again... $30 or so....?
Sure got my money's worth out of the last one.. LOL...!
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| Re: [GMCnet] spark plug questions, please [message #133515 is a reply to message #133508] |
Wed, 06 July 2011 14:01  |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
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Senior Member |
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| Ek_Lektro wrote on Wed, 06 July 2011 12:56 |
Anybody know if GMCMHI has been keeping the parts index up to date?
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My copy (arrived in the mail a few days ago) says "Spring 2011, supersedes Spring 2010", so YES to that.
There are 30 or so replacements listed, depending on year and engine. I'm guessing you have a 455, 1975-1977...
The new AC part number is R46SZ (0.080 gap).
The Champion and Bosch numbers are still listed as current.
The Autolite number is still current, still no gap listed.
Also, NAPA Champion (CHA) 0.080 gap, part # 66.
1973 Sequoia 260 (since 2011)
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| Re: [GMCnet] spark plug questions, please [message #133522 is a reply to message #133508] |
Wed, 06 July 2011 14:56 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Greg,
You can look at an application on the GMC photo site.
http://tinyurl.com/2dnjlgv
| Ek_Lektro wrote on Wed, 06 July 2011 12:56 |
Well, its been a while.... and its definitely time for a new set of plugs!
not sure which ones to buy...
When i pulled a few of the old ones out, the gaps on them ranged from .45 to .70...
no wonder it was running crappy? (Can the gap change that much over time?
or is it more likely that the previous mechanic botched the gapping job?)
(and/or which to avoid), and of course, the recommended gap spec?
OK, thanks much for any info....
Greg
SolarSonic / LosAngeles
PS: No surprise, I've noticed that some of the parts numbers in this '98 index are starting to become obsolete
at AutoZone, etc. Wondering if this is mainly due to the parts in general getting more scarce over the years,
or if perhaps its just time for a new Parts Interchange Index?
Anybody know if GMCMHI has been keeping the parts index up to date?
If so, i think it'd be time to subscribe again... $30 or so....?
Sure got my money's worth out of the last one.. LOL...!
|
Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] spark plug questions, please [message #133529 is a reply to message #133508] |
Wed, 06 July 2011 16:09 |
powerjon
Messages: 2446
Registered: January 2004
Karma: 5
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Senior Member |
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Here is a listing of plugs that can be used with the GMC. It is
mostly current, but I need to update again with the latest numbers.
http://www.gmcmhphotos.com/photos/data/5237/Spark_Plug_Application_Gu.pdf
JR Wright
On Jul 6, 2011, at 1:56 PM, Ek_Lektro wrote:
> Well, its been a while.... and its definitely time for a new set of
> plugs!
> not sure which ones to buy...
> When i pulled a few of the old ones out, the gaps on them ranged
> from .45 to .70...
> no wonder it was running crappy? (Can the gap change that much over
> time?
> or is it more likely that the previous mechanic botched the gapping
> job?)
>
> So i checked the cross reference on my GMC Motorhome International
> Parts Interchange Index (circa 1998!)
> and for my '76 455, these are all listed as compatible:
> AC R46SX with .80 gap
> Bosch WR10FCZ with .80 gap
> Champion RJ18YC6 with .60 gap
> AutoLite 847 with no gap spec listed
>
> i
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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
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| Re: [GMCnet] spark plug questions, please [message #133550 is a reply to message #133508] |
Wed, 06 July 2011 18:50 |
shawnee
Messages: 422
Registered: February 2004
Location: NC
Karma: 0
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Senior Member |
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| Ek_Lektro wrote on Wed, 06 July 2011 13:56 |
Well, its been a while.... and its definitely time for a new set of plugs!
not sure which ones to buy...
When i pulled a few of the old ones out, the gaps on them ranged from .45 to .70...
no wonder it was running crappy? (Can the gap change that much over time?
or is it more likely that the previous mechanic botched the gapping job?)
So i checked the cross reference on my GMC Motorhome International Parts Interchange Index (circa 1998!)
and for my '76 455, these are all listed as compatible:
AC R46SX with .80 gap
Bosch WR10FCZ with .80 gap
Champion RJ18YC6 with .60 gap
AutoLite 847 with no gap spec listed
in this same index, i can see that for other GMC years, the recommended gap can range from .40 to .80...
Considering that this '76 engine was supposedly rebuilt back in 2002,
is it safe to assume that they rebuilt the same engine, and that the same spark plug specs apply?
Bottom line, what's the conventional wisdom say about best plugs to use,
(and/or which to avoid), and of course, the recommended gap spec?
OK, thanks much for any info....
Greg
SolarSonic / LosAngeles
PS: No surprise, I've noticed that some of the parts numbers in this '98 index are starting to become obsolete
at AutoZone, etc. Wondering if this is mainly due to the parts in general getting more scarce over the years,
or if perhaps its just time for a new Parts Interchange Index?
Anybody know if GMCMHI has been keeping the parts index up to date?
If so, i think it'd be time to subscribe again... $30 or so....?
Sure got my money's worth out of the last one.. LOL...!
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Gene Dotson
74 Canyonlands
www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
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| Re: [GMCnet] spark plug questions, please [message #133555 is a reply to message #133550] |
Wed, 06 July 2011 19:47 |
Len Novak
Messages: 676
Registered: February 2004
Location: Las Vegas, NV
Karma: -3
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Senior Member |
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From a fellow GMCer....
This is a list of plug that I have found that should work in the 455 & 403
engines. If you have others that work you can add to the list.
Brand 455 Eng Style 403
Eng
Style
AC/Delco R46SZ Std. Same
AC/Delco 41-818 Plt. Same
AC/Delco AC#7 Plt. Same
Autolite AP847 Plt.
847
Std.
Bosch 4023 Plt.
4022
Plt.
Bosch 7921 Std.
7920
Std.
NKG 4536 Std. Same
NKG 7293 Iridium Same
--
J.R. Wright
GMC Great Laker
GMCMHI
TZE Zone Restorations
77 Eleganza II (For Sale)
75 Avion (Under going Frame up Restoration) On Location at Florida Space
Coast _______________________________________________
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Len and Pat
78 Kingsley, The Beast II with dash lights that work
Fallbrook, CA
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
www.bdub.net/novak/
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Gene Dotson
Sent: Wednesday, July 06, 2011 4:51 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] spark plug questions, please
Ek_Lektro wrote on Wed, 06 July 2011 13:56
> Well, its been a while.... and its definitely time for a new set of plugs!
> not sure which ones to buy...
> When i pulled a few of the old ones out, the gaps on them ranged from .45
to .70...
> no wonder it was running crappy? (Can the gap change that much over time?
> or is it more likely that the previous mechanic botched the gapping job?)
>
> So i checked the cross reference on my GMC Motorhome International Parts
Interchange Index (circa 1998!)
> and for my '76 455, these are all listed as compatible:
> AC R46SX with .80 gap
> Bosch WR10FCZ with .80 gap
> Champion RJ18YC6 with .60 gap
> AutoLite 847 with no gap spec listed
>
> in this same index, i can see that for other GMC years, the recommended
gap can range from .40 to .80...
> Considering that this '76 engine was supposedly rebuilt back in 2002,
> is it safe to assume that they rebuilt the same engine, and that the same
spark plug specs apply?
>
> Bottom line, what's the conventional wisdom say about best plugs to use,
> (and/or which to avoid), and of course, the recommended gap spec?
>
> OK, thanks much for any info....
> Greg
> SolarSonic / LosAngeles
>
> PS: No surprise, I've noticed that some of the parts numbers in this '98
index are starting to become obsolete
> at AutoZone, etc. Wondering if this is mainly due to the parts in general
getting more scarce over the years,
> or if perhaps its just time for a new Parts Interchange Index?
> Anybody know if GMCMHI has been keeping the parts index up to date?
> If so, i think it'd be time to subscribe again... $30 or so....?
> Sure got my money's worth out of the last one.. LOL...!
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
--
Gene Dotson
74 Canyonlands
www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
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_______________________________________________
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Unsubscribe or Change List Options:
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Len and Pat Novak
1978 GMC Kingsley
The Beast II with dash lights that work and labels you can see!
Las Vegas, NV new email: B52sRule@Gmail.com
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
www.bdub.net/novak/
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| Re: [GMCnet] spark plug questions, please [message #133634 is a reply to message #133632] |
Thu, 07 July 2011 09:33 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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| philipswanson wrote on Thu, 07 July 2011 09:26 |
The new #7 is not the same plug as before. It has the old Champion style tip....... garbage. Try to find the old #7s much better plug.
Phil Swanson
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I have heard that but have never seen one. I put some in several years ago and will not worry about ever changing plugs again. I heard Dick Paterson is recommending a new plug by a different manufacturer. I do not know what that one is.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] spark plug questions, please [message #133671 is a reply to message #133632] |
Thu, 07 July 2011 14:22 |
Don A
Messages: 895
Registered: October 2008
Location: Dallas, TX
Karma: 0
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Senior Member |
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Anybody have a picture of the old #7 tip?
| philipswanson wrote on Thu, 07 July 2011 09:26 |
The new #7 is not the same plug as before. It has the old Champion style tip....... garbage. Try to find the old #7s much better plug.
Phil Swanson
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Don Adams Dallas, TX
'76 26' Glenbrook, '90 Sidekick
rebuilt by R Archer, powered by J Bounds, Koba
[IMG]http://www.gmcmhphotos.com/photos/data/6109/G2.jpg[/IMG]
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