reading spark plugs after using gasohol

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Ian in Mississauga

Senior Member
I put in new Champion W16Y plugs last week before going on tour with the club. The car ran fine , the gav was closed, most times we drove between 40 & 50 mph. When I got home 300 mi. later I pulled the plugs and the porcelains were still white. The old plugs would usually show a bit of soot. A buddy suggested that maybe gasohol burns cleaner. Your thoughts?
TIA, Ian
 
You said the gav was closed! I think you are running it to lean. Try running with the gav cracked open about a eight to a quarter turn open!!!
 
I have done some testing on the dynomometer that was used for emission testing in NJ, when it was first installed i ran my car --before they changed the gas, I just recently ran the car again, the emissions were lower, before I could close the GAV all the way and still be somewhat rich, now I need to open the GAV slightly so I am not too lean.
With the GAV closed I could get emission levels that are good for cars in the 1990s, but it was too lean to have good power on the road, 1/8 turn up to 40 mph, 1/4 turn above 40 gives me a good mixture that will give a light tan burn on the plugs, the emissions of a late 70s car and good power, and 1/3 -1/2 for over 55. I am using 3X plugs, and can burn them white if i close the gav.

Having the GAV makes the model A very adaptable to different fuels, you just have to learn the feel of too rich, or lean.
 
Good points, all. Ethanol chemically leans the fuel-air mixture by bringing oxygen in with the fuel (thus reducing carbon monoxide emissions). Turning the GAV counterclockwise to richen the mixture is the right thing to do with an ethanol fuel. As mentioned, each Model A runs a little differently than the next and you have to find your sweet spot.
 
Old182 said:
Ethanol chemically leans the fuel-air mixture by bringing oxygen in with the fuel (thus reducing carbon monoxide emissions). Turning the GAV counterclockwise to richen the mixture is the right thing to do with an ethanol fuel. As mentioned, each Model A runs a little differently than the next and you have to find your sweet spot.
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I'm not sure it brings oxygen in with the fuel but rather it requires MORE alcohol to achieve the same power as gasoline. (About 30% more.) That's why it's necessary to increase the main-jet size for carbureted vehicles running alcohol. Modern E85 vehicles simply vary the pulse width of the fuel injectors to feed more fuel. Opening up the GAV is simply increasing fuel flow which would be needed to run alcohol or high alcohol content gasoline. In either case, it takes more fuel so fuel mileage goes down. But it does burn cleaner. :cool:
 
CCWKen, love your avatar; what kind of car is that? Reminds me of a '57 Studebaker Golden Hawk, but isn't that, I know.
re: the topic, I run premium non-oxygenated gas exclusively in m 30 coupe, and I have a hard time telling any difference when I close my GAV completely. I've checked my rebuilt Zenith and the GAV needle DOES close off the port (checked by blowing with a straw, etc... per one of the rebuild book's instructions), and I can just barely tell the difference when idling if I close it completely. But driving, I can turn it 'off' and not see any power loss. Do you think this is due to the premium gas? I remember my Tillotson was much more sensitive to closing the GAV, but have not run the Tilly since I got the Zenith 10 years ago.
 
CCWKen: It's the 35% oxygen in ethanol (CH3CH2OH) that reduces mileage (no heat energy in O). Ethanol chemically leans the mixture because of its oxygen, and helps the combustion reaction go all the way to CO2 instead of stopping at CO (an EPA-regulated pollutant). There's more, but it gets nerdy. :o
 
Old182 is correct. Gasoline containing ethanol is also known as "Oxygenated Gasoline" which means it is contains oxygen. The oxygen or oxygenates are in the ethanol.

The environmental Libs decided that oxygenated gasoline would reduce carbon monoxide emissions as compared to conventional gas. Oxygenated gas requires less oxygen from the air for compete burning than the same volume of conventional gas. Adding oxygenate is like adding more air. So for the same carb setting, using oxygenated gas produces a less rich mixture and therefore generates less carbon monoxide when it burns.

So the common man breathes better and since the government sends him a free monthly check anyway it's no problem for him to buy and burn more gas than he would have with conventional gas to cover the same amount of miles.

Yep, the environmentalist knows what's best for you and me .... but while he's smoking a doobie or two, the carbon monoxide inhaled by the environmentalist does not seem to be an issue.


Larry B.
 
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Ian in Mississauga said:
I put in new Champion W16Y plugs last week before going on tour with the club. The car ran fine , the gav was closed, most times we drove between 40 & 50 mph. When I got home 300 mi. later I pulled the plugs and the porcelains were still white. The old plugs would usually show a bit of soot. A buddy suggested that maybe gasohol burns cleaner. Your thoughts?
TIA, Ian
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Ian, I wouldn't pay much attention to the exact GAV settings discussed by the other posters. The GAV will vary from one engine to the next.

Always set the GAV to wherever YOUR engine runs the best regardless of the fuel choice. Then run a heat range test on the plugs.

Now concerning your white spark plug if you idled the engine or drove the car slower, the color of the electrode is not a true indication of the heat. The heat will be less than what it is when you are cruising. You need to run a proper heat range test to be sure. If the plug is bright white after idling or slow driving more than likely it's too hot for your particular engine set up and driving habits.


Larry B.
 
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Barry in St.Paul said:
CCWKen, love your avatar; what kind of car is that? Reminds me of a '57 Studebaker Golden Hawk, but isn't that, I know.
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It's a 1951 Chrysler K310. I'm building one! Or will one of these days when I can get all the other projects out. I have a 51 Chrysler Imperial with the first Hemi that I plan on using for the chassis and running gear just like Chrysler did. The body, for the most part, will be hand made. It was a Ghia design and I really like the "Rolls" look about it.

I have a 56 Silver Hawk and 57 Golden Hawk. That's part of the "other projects". :cool:

Old182 - I stand corrected. I never pay much attention or keep up with the new-fangled fads. :D
 
Gasohol which is water absorbing alcohol in gasoline to stretch the Nation's gas supply and as a concession to corn and other plant producers does nothing for gasoline, especially in a low compression engine like our 'A's. Water absorbed and burned just comes out as water and regular exhaust.

Since your burning lean I'd say that why she's not sooted up.

skip.
 
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