How Do Your Spark Plugs Look.... Checked Lately.... If Your Burning 10% Ethanol..??
11-24-2015, 09:44 PM
#1
Le Mans Master
Thread Starter
How Do Your Spark Plugs Look.... Checked Lately.... If Your Burning 10% Ethanol..??
Just curious if any one has looked at their plugs lately if you 've been running that 10% gack in your gas. My friends plugs have shown much more blackest soot around the plug.
I know their are many factors in plug color such as heat rang ..Blah ..Blah.
Some states don't use it ..How about your state...?
I know their are many factors in plug color such as heat rang ..Blah ..Blah.
Some states don't use it ..How about your state...?
11-24-2015, 10:03 PM
#2
Instructor
Mass has 10% ethanol, plugs have 2500 miles. Plugs have a light tan color.
That's on a 64 327 300hp. Premium gas. Been using the 10% for 15 years with out
problems.
Bob D.
That's on a 64 327 300hp. Premium gas. Been using the 10% for 15 years with out
problems.
Bob D.
11-24-2015, 10:11 PM
#3
Le Mans Master
Thread Starter
Lets me change the A/F Mix ant the touch of a Button.
My bud's 350 CID looks sooty as heck. It's carbed ..so somethings wrong.
11-24-2015, 10:46 PM
#4
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St. Jude Donor '13-'14-'15-'16
Perfect... Sounds right..Nice tan color on the center electrode.. I'm running 93 Octane (Shell V-Power) 10% Gack. Using the MSD Atomic EFI system. Got the same color.
Lets me change the A/F Mix ant the touch of a Button.
My bud's 350 CID looks sooty as heck. It's carbed ..so somethings wrong.
Lets me change the A/F Mix ant the touch of a Button.
My bud's 350 CID looks sooty as heck. It's carbed ..so somethings wrong.
11-25-2015, 11:43 AM
#5
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All we have in CA where I am is the alky fuel. It won't cause plugs to blacken....just the opposite. It causes leaner operation. The only thing that'll blacken the plugs is what vetsvette stated: rich or engine wear.
11-25-2015, 12:07 PM
#6
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Mine look about the same. It doesn't seem to be a problem at all. I can remember many years ago when you could still buy leaded premium everywhere, the plugs only lasted about 3,000 miles or 1 year. Now I only change them every 3 years or so just because they've been in there so long. They usually look as you described on my big block and small blocks.
11-25-2015, 01:29 PM
#7
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I thought my 60 was running rich , so this summer I pulled a couple plugs and after looking at em I just put my jet box away. I patted it on the air cleaner and called it a "good girl " The plugs were just a nice tan color w/just some white on the insulator. Just the way I like em !
11-25-2015, 02:43 PM
#8
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2000 miles on California premium (E10, 91 octane)
11-25-2015, 03:55 PM
#9
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E10 has about three percent oxygen by mass, so with more oxygen available compared to straight gasoline, excess carbon deposits on the plugs should not be an issue if everything is to OE spec on an OE engine.
As stated excess carbon deposits on plugs are due to other issues such as excess oil consumption, modifications that alter the OE A/F ratio, and too cold spark plug heat range.
The light tan color previously described means everything is okay, and the plugs should provide good service for at least 15K miles and easily double that.
Lead fouling due to too cold OE plugs and the high amount of TEL in vintage gasoline is why plug life was short back in the day.
Duke
As stated excess carbon deposits on plugs are due to other issues such as excess oil consumption, modifications that alter the OE A/F ratio, and too cold spark plug heat range.
The light tan color previously described means everything is okay, and the plugs should provide good service for at least 15K miles and easily double that.
Lead fouling due to too cold OE plugs and the high amount of TEL in vintage gasoline is why plug life was short back in the day.
Duke
Last edited by SWCDuke; 11-25-2015 at 03:58 PM.
11-25-2015, 04:18 PM
#10
Le Mans Master
Thread Starter
E10 has about three percent oxygen by mass, so with more oxygen available compared to straight gasoline, excess carbon deposits on the plugs should not be an issue if everything is to OE spec on an OE engine.
As stated excess carbon deposits on plugs are due to other issues such as excess oil consumption, modifications that alter the OE A/F ratio, and too cold spark plug heat range.
The light tan color previously described means everything is okay, and the plugs should provide good service for at least 15K miles and easily double that.
Lead fouling due to too cold OE plugs and the high amount of TEL in vintage gasoline is why plug life was short back in the day.
Duke
As stated excess carbon deposits on plugs are due to other issues such as excess oil consumption, modifications that alter the OE A/F ratio, and too cold spark plug heat range.
The light tan color previously described means everything is okay, and the plugs should provide good service for at least 15K miles and easily double that.
Lead fouling due to too cold OE plugs and the high amount of TEL in vintage gasoline is why plug life was short back in the day.
Duke
11-25-2015, 05:54 PM
#11
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Just curious if any one has looked at their plugs lately if you 've been running that 10% gack in your gas. My friends plugs have shown much more blackest soot around the plug.
I know their are many factors in plug color such as heat rang ..Blah ..Blah.
Some states don't use it ..How about your state...?
I know their are many factors in plug color such as heat rang ..Blah ..Blah.
Some states don't use it ..How about your state...?
I use AC R45S plugs.
Years ago (1960's/1970's) I could foul a set of plugs in anywhere between 2K and 10K miles to the point they'd misfire. It depended on what engine, carb, gears, use of vehilce, etc., and it also a result of using leaded gasoline.
My first daily driver when unleaded gas came along was a 1971 Cheyenne pickup. It had a 151 cam in it, 780 Holley, the dual point 270 distributor, dual exhaust and a few other mods. It was also the first year for the "peanut" spark plugs. Running on leaded gas, the first time I changed plugs was about 10k and it started misfiring a little. I drove the truck to work and back every day. Also pulled heavy trailers with it from time/time.
The next set of plugs and from there on out through almost 180K miles was on unleaded gasoline. The plug change interval went to 40K miles and I guess I can't really say the plugs were fouled or missing. The gap was worn way wide but not crudded up with lead deposits. I can't remember my point change interval but I think it was extended to as the points didn't have to work as hard to fire plugs that weren't fouled/dirty.
Getting the lead out is the best thing that ever happened to daily drivers.
Last edited by MikeM; 11-25-2015 at 05:55 PM.
11-25-2015, 08:51 PM
#12
Le Mans Master
Thread Starter
Mark. The plugs in my 327/360 w/Rochester FI are almost perfectly clean with a slight tinge of tan. Very slight. That's after a couple thousand miles of driving. Last I looked at them was about five years ago. Engine runs the same. Doesn't misfire that I can tell. I'd bet if I pulled them today, they'd look the same as they did several years/miles ago.
I use AC R45S plugs.
Years ago (1960's/1970's) I could foul a set of plugs in anywhere between 2K and 10K miles to the point they'd misfire. It depended on what engine, carb, gears, use of vehilce, etc., and it also a result of using leaded gasoline.
My first daily driver when unleaded gas came along was a 1971 Cheyenne pickup. It had a 151 cam in it, 780 Holley, the dual point 270 distributor, dual exhaust and a few other mods. It was also the first year for the "peanut" spark plugs. Running on leaded gas, the first time I changed plugs was about 10k and it started misfiring a little. I drove the truck to work and back every day. Also pulled heavy trailers with it from time/time.
The next set of plugs and from there on out through almost 180K miles was on unleaded gasoline. The plug change interval went to 40K miles and I guess I can't really say the plugs were fouled or missing. The gap was worn way wide but not crudded up with lead deposits. I can't remember my point change interval but I think it was extended to as the points didn't have to work as hard to fire plugs that weren't fouled/dirty.
Getting the lead out is the best thing that ever happened to daily drivers.
I use AC R45S plugs.
Years ago (1960's/1970's) I could foul a set of plugs in anywhere between 2K and 10K miles to the point they'd misfire. It depended on what engine, carb, gears, use of vehilce, etc., and it also a result of using leaded gasoline.
My first daily driver when unleaded gas came along was a 1971 Cheyenne pickup. It had a 151 cam in it, 780 Holley, the dual point 270 distributor, dual exhaust and a few other mods. It was also the first year for the "peanut" spark plugs. Running on leaded gas, the first time I changed plugs was about 10k and it started misfiring a little. I drove the truck to work and back every day. Also pulled heavy trailers with it from time/time.
The next set of plugs and from there on out through almost 180K miles was on unleaded gasoline. The plug change interval went to 40K miles and I guess I can't really say the plugs were fouled or missing. The gap was worn way wide but not crudded up with lead deposits. I can't remember my point change interval but I think it was extended to as the points didn't have to work as hard to fire plugs that weren't fouled/dirty.
Getting the lead out is the best thing that ever happened to daily drivers.
All excellent points Chief. I've heard your FI run down at BG at the Hotel when you brought it one year along with (***** 1). My other vettes ran nice and clean and had that nice tan color. I use to get plenty of mileage out of the plugs back in the day.
I use to like to see that Nice light gray color in the end of the exhaust pipe. That told me My plugs were tan. But again that was with Lead in the go juice. Glad it's gone and we now have hardened Valve Seats and Valves.
I always liked your FI Vette.... If it ain't broke....Don't fix it
11-27-2015, 10:41 PM
#15
Le Mans Master
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11-27-2015, 10:43 PM
#16
Le Mans Master
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11-28-2015, 12:04 PM
#18
Le Mans Master
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11-28-2015, 12:33 PM
#19
Race Director
11-28-2015, 01:59 PM
#20
Le Mans Master
