Galvanic Corrosion in AFB Carburetor
11-22-2015, 07:25 AM
#1
Galvanic Corrosion in AFB Carburetor
If have been having issues with a fouling carb and now see pits in the fuel bowl that I believe is being caused by galvanic corrosion of the aluminum by ethanol, and by association moisture, in the fuel. There are some discussions on the web that the moisture ethanol introduces to the fuel system can create the potential (pun intended) for current to flow. I am considering coating the bottom of the bowl with Marine TEX resin. Any other ideas?
11-22-2015, 08:05 AM
#2
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1974CorvetteJimCr (11-25-2015)
11-22-2015, 09:00 AM
#4
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I sure wish I'd known not to use E 10 back before E 10 was on the market and I used to take carbs apart that were crusty white inside due to corrosion and some eaten up to the point of being unusable.
That was twenty-five, thirty years or so ago.
Dried, gummy gas deposits and water in the fuel have been around as long as gasoline has been used in cars.
That was twenty-five, thirty years or so ago.
Dried, gummy gas deposits and water in the fuel have been around as long as gasoline has been used in cars.
11-22-2015, 09:15 AM
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I sure wish I'd known not to use E 10 back before E 10 was on the market and I used to take carbs apart that were crusty white inside due to corrosion and some eaten up to the point of being unusable.
That was twenty-five, thirty years or so ago.
Dried, gummy gas deposits and water in the fuel have been around as long as gasoline has been used in cars.
That was twenty-five, thirty years or so ago.
Dried, gummy gas deposits and water in the fuel have been around as long as gasoline has been used in cars.
yes Mike
11-23-2015, 08:30 PM
#6
Race Director
E-10 not the problem. Used it for years in CT in all cars including the'62. Not a hint of any corrosion or other problem even with car sitting for over 6 months at a time.
A few years back I bought a NOS carb for an early 50's car. Still sealed in box. When I opened it it had a lot of corrosion and flaking. Sometimes it's the quality of the pot metal, or some other outside factor. It is not due to use of good quality E-10
A few years back I bought a NOS carb for an early 50's car. Still sealed in box. When I opened it it had a lot of corrosion and flaking. Sometimes it's the quality of the pot metal, or some other outside factor. It is not due to use of good quality E-10
11-24-2015, 06:28 PM
#7
Race Director
I recently had to replace a Holley carb with the shiny coating fora customer. When I called into Holley ( just for the heck of it)...The customer service rep had me give him the numbers off the air horn. They told me that they had a bad batch of carbs with defective coating...and this carb is in that timeline. They sent out a free carb.On another note...I do not use gasoline with ethanol....and here is WHY. There is a tool that you can buy rather inexpensively that will let you know how much ethanol is in your fuel. I had a very good friend/mechanic that was working on a Porsche and when he tested the fuel...ti was at 22% ethanol and the car was running like crap.
And when I got this tool. I tested many Corvettes in my shop because I wanted to see for myself. Most cars were at 8%. BUT that is not what gave me the biggest concern.
What made me shake my head was when I tested some NON-ethanol fuel that I have at my shop...when I preformed the test. The water and fuel separated and BOTH were back to CRYSTAL CLEAR in UNDER one minute.
When I preformed the SAME test with some of the fuel out of a customers car....The water and fuel separated out in about a minute or two...where you could take a reading....BUT...here is what gives me concern....is that it took 6 hours for the two to separate out and BOTH be crystal clear instead of a murky mix of both. SO..this makes me wonder what 'blend' of fuel are they using and then adding alcohol to it to raise up the octane to what they say it is. Becasue as you know...alcohol has a higher octane rating that gasoline...but it takes more of it to provide the same power.
DUB
11-24-2015, 07:54 PM
#8
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In CA, where I am, ethanol-laced fuel is the only fuel available. The cure is not to let the fuel sit too long. Regular driving takes care of that. I don't use any additives in any of my cars, and have not had any issues other than decreased fuel mileage and increased vapor leak issues from time to time in various vehicles. Carbs jetted for regular pure gasoline also tend to run a bit lean on ethanol blends, leading to hotter operating temps and detonation. The stuff is a huge farce.
11-25-2015, 08:48 AM
#9
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I recently had to replace a Holley carb with the shiny coating fora customer. When I called into Holley ( just for the heck of it)...The customer service rep had me give him the numbers off the air horn. They told me that they had a bad batch of carbs with defective coating...and this carb is in that timeline. They sent out a free carb.On another note...I do not use gasoline with ethanol....and here is WHY. There is a tool that you can buy rather inexpensively that will let you know how much ethanol is in your fuel. I had a very good friend/mechanic that was working on a Porsche and when he tested the fuel...ti was at 22% ethanol and the car was running like crap.
And when I got this tool. I tested many Corvettes in my shop because I wanted to see for myself. Most cars were at 8%. BUT that is not what gave me the biggest concern.
What made me shake my head was when I tested some NON-ethanol fuel that I have at my shop...when I preformed the test. The water and fuel separated and BOTH were back to CRYSTAL CLEAR in UNDER one minute.
When I preformed the SAME test with some of the fuel out of a customers car....The water and fuel separated out in about a minute or two...where you could take a reading....BUT...here is what gives me concern....is that it took 6 hours for the two to separate out and BOTH be crystal clear instead of a murky mix of both. SO..this makes me wonder what 'blend' of fuel are they using and then adding alcohol to it to raise up the octane to what they say it is. Becasue as you know...alcohol has a higher octane rating that gasoline...but it takes more of it to provide the same power.
DUB
11-25-2015, 10:19 AM
#10
Pure Gas web site and App
I too do not use gasoline with ethanol in it. Here is the link you can click on to get to the Pure Gas web site, non profit and its FREE. You can also add gas stations to the list when you find one not listed.
http://pure-gas.org/
http://pure-gas.org/
11-25-2015, 11:19 AM
#11
If have been having issues with a fouling carb and now see pits in the fuel bowl that I believe is being caused by galvanic corrosion of the aluminum by ethanol, and by association moisture, in the fuel. There are some discussions on the web that the moisture ethanol introduces to the fuel system can create the potential (pun intended) for current to flow. I am considering coating the bottom of the bowl with Marine TEX resin. Any other ideas?
11-25-2015, 06:48 PM
#12
Race Director
This is the tool I have...SORRY about the video...its not MINE (obviously)...but hopefully this helps fill n any blanks that my writing did not cover.
This tool is quite inexpensive.
DUB