spark plug gap

smokensteve · 01-21-2008, 09:51 PM

What are peoples opinion on pre gapped spark plugs...had an argument with a friend about them...I always gap my plugs when putting them in an engine..also, what are some things that can happen to an engine with the wrong plug gap?....thanks for any info

gmtech · 01-21-2008, 09:54 PM

I'm with you always check and adjust gap. biggest problem with not checking the gap is when it is too small you have improper spark and can cause a misfire

junior3382 · 01-21-2008, 09:57 PM

Timming in todays motors are so percise that the gap is very important. Off my a bit can cause a significant lag in timing and power. As for pregapped plugs, it depends on the plugs. Like the Bish Platinum +4's, you do not have a choice but to get them pregapped. in that case, I have noticed a difference in performance, but not enough to justify the cost. If it is a single prong plug though, I woul gap my own, just because I would be **** enough to make sure it was done right.

smokensteve · 01-21-2008, 10:05 PM

yes... It doesn't make sence to me "pre gapped" unless all engines that that paticular plug fits, all have the same gap, how can they say they are pre gapped...like I'm sure the pre gapped plug will fit several engines not just one...so all those engines would have the same gap

o3shortbed · 01-22-2008, 08:45 PM

i always regap my plugs. the platinum plugs tend to last so long (100k on my 03 chevy) that it makes since to try and keep them as close to the specs. as you can

lonestar1128 · 01-24-2008, 09:53 AM

in my personal opinion, the bush +4 (4-pronged plugs) aren't woth the money. in addition they are "pre-gapped" but not necessarily properly gapped. I change my plugs once a year, needed or not, and i've been thru several sets of plugs that claim to be pre-gapped. However, i've never bought a full set of 8 that were all correct.

My recommendation: ALWAYS check them yourself, and don't waste money on plugs like the +4 that you can't fit a gapper in. Most auto parts stores sell plug gappers for $0.75, too cheap and easy not to do it.

Edit: A properly gapped plug will be wide enough to burn hot, but not so wide that it skips or misses at high speeds, causing that cylinder to drag, or the engine to begin to rattle. -Wikipedia
Spark plug - Wikipedia, the free encyclopedia

fbhart@wk.net · 01-26-2008, 09:28 PM

lonestar1128:

You change plugs every year, I have 79K on my 350 engine and have never changed plugs.

Old truck still starts and runs good, however, I was wondering how difficult it is going to be removing the plugs. Maintenance schedule says 100K I think.

What is best plug to replace with, ones currently in truck have been good.

If I replace plugs should I also replace wires and distributor cap, rotor, etc:.

Also, what about shocks, they have never been replaced, how long do they usually last?
Truck is a 3/4 ton and rides like a log wagon anyway, so who would know if they need replacing.

Thanks, for suggestions;

1979_4x4_Plow · 01-26-2008, 09:56 PM

i use ac delco plugs in my truck, but i think the truck had original plugs in it from when it was new in 1979. either way, the truck is happier and sounds & runs better

if you do plugs, get wires and a decent cap that has brass tips. i go with accel cap and rotor kit sice it is better quality and cheaper to get t than the cap and rotor separate.

01-21-2008, 09:51 PM	#1
smokensteve Senior Member Join Date: Jan 2007 Location: North Vancouver BC Posts: 86	spark plug gap What are peoples opinion on pre gapped spark plugs...had an argument with a friend about them...I always gap my plugs when putting them in an engine..also, what are some things that can happen to an engine with the wrong plug gap?....thanks for any info

01-21-2008, 09:57 PM	#3
junior3382 Senior Member Join Date: Mar 2007 Location: I live in south central PA, but grew up in Maine Posts: 2,937	Timming in todays motors are so percise that the gap is very important. Off my a bit can cause a significant lag in timing and power. As for pregapped plugs, it depends on the plugs. Like the Bish Platinum +4's, you do not have a choice but to get them pregapped. in that case, I have noticed a difference in performance, but not enough to justify the cost. If it is a single prong plug though, I woul gap my own, just because I would be ** enough to make sure it was done right. __________________ Lets get some mud on the tires...eh?!?!? OWN:** 1998 Chevy Blazer ls 4x4 4.3l Vortec V6 1998 Mazda B3000 SE 4WD 3.0L V6 3" lift 31x10.50 Liberator A/T's

01-24-2008, 09:53 AM	#6
lonestar1128 Full Member Join Date: Jan 2008 Location: Salt Lake City, UT Posts: 44	in my personal opinion, the bush +4 (4-pronged plugs) aren't woth the money. in addition they are "pre-gapped" but not necessarily properly gapped. I change my plugs once a year, needed or not, and i've been thru several sets of plugs that claim to be pre-gapped. However, i've never bought a full set of 8 that were all correct. My recommendation: ALWAYS check them yourself, and don't waste money on plugs like the +4 that you can't fit a gapper in. Most auto parts stores sell plug gappers for $0.75, too cheap and easy not to do it. Edit: A properly gapped plug will be wide enough to burn hot, but not so wide that it skips or misses at high speeds, causing that cylinder to drag, or the engine to begin to rattle. -Wikipedia Spark plug - Wikipedia, the free encyclopedia __________________ 73 K20 4spd manual 6" w/35x12.50 BFG's 95 Tahoe LT 2dr/4WD 6" w/35x12.50 BFG's

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Spark plug wiring diagram	Detailer054	Chevy Truck Forum	8	01-10-2008 11:37 PM
1992 5.7 TBI #1 Spark plug fouling	cplnorton	Chevy Truck Forum	7	11-09-2007 08:37 PM
spark plug wires help	braggent	Chevy Truck Forum	5	06-17-2006 06:44 AM
spark plug	project88	General Truck Forum	8	05-08-2006 10:09 AM
One fouled spark plug on 95 K1500	tackepj	Chevy Truck Forum	9	05-05-2006 12:17 PM

01-21-2008, 09:54 PM	#2
gmtech Senior Member Join Date: Dec 2005 Location: farmville Va Posts: 342	I'm with you always check and adjust gap. biggest problem with not checking the gap is when it is too small you have improper spark and can cause a misfire

01-21-2008, 10:05 PM	#4
smokensteve Senior Member Join Date: Jan 2007 Location: North Vancouver BC Posts: 86	yes... It doesn't make sence to me "pre gapped" unless all engines that that paticular plug fits, all have the same gap, how can they say they are pre gapped...like I'm sure the pre gapped plug will fit several engines not just one...so all those engines would have the same gap

01-22-2008, 08:45 PM	#5
o3shortbed Senior Member Join Date: Jan 2008 Location: L-burg KY Posts: 314	i always regap my plugs. the platinum plugs tend to last so long (100k on my 03 chevy) that it makes since to try and keep them as close to the specs. as you can

01-26-2008, 09:28 PM	#7
fbhart@wk.net Senior Member Join Date: Mar 2007 Posts: 86	lonestar1128: You change plugs every year, I have 79K on my 350 engine and have never changed plugs. Old truck still starts and runs good, however, I was wondering how difficult it is going to be removing the plugs. Maintenance schedule says 100K I think. What is best plug to replace with, ones currently in truck have been good. If I replace plugs should I also replace wires and distributor cap, rotor, etc:. Also, what about shocks, they have never been replaced, how long do they usually last? Truck is a 3/4 ton and rides like a log wagon anyway, so who would know if they need replacing. Thanks, for suggestions;

01-26-2008, 09:56 PM	#8
1979_4x4_Plow Senior Member Join Date: Dec 2007 Posts: 98	i use ac delco plugs in my truck, but i think the truck had original plugs in it from when it was new in 1979. either way, the truck is happier and sounds & runs better if you do plugs, get wires and a decent cap that has brass tips. i go with accel cap and rotor kit sice it is better quality and cheaper to get t than the cap and rotor separate.