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DougB Samba Member
Joined: January 09, 2007 Posts: 1076 Location: Falls Church, Virginia, USA
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Posted: Thu May 19, 2016 7:49 am Post subject: Ethanol and our FI engines? |
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Hello all,
I know a general question about Ethanol's effects on VWs wouldn't be right for here, but I did want to specifically ask about how an increase in the Ethanol percentage in blended fuels might affect our FI bus engines (mine's a '75). Around me it's nearly impossible to find pure gasoline, and everything has 10% Ethanol. Not it sounds like the EPA is considering increasing the percentage (I added a bunch of info about it in this General/Chat forum thread:
http://www.thesamba.com/vw/forum/viewtopic.php?t=5...highlight=
Just wondering how this might affect our engines, e.g. if it went up to E15.
Thanks in advance!
- Doug _________________ '75 Campmobile (tin-top to SpaceRoof)
'73 Fastback
'52 BMW R67/2
'41 Zundapp KS600
'55 Puch SGS250
A very, very understanding wife |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Thu May 19, 2016 8:33 am Post subject: Re: Ethanol and our FI engines? |
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Ethanol is:
5 Hydrogen
2 Carbon
1 Oxygen
when burned it would be 5 H2O, 2 CO2
Gasoline is a combination but something typical like:
6 Hydrogen
6 Carbon
When burned I believe it would be 6 H20 and 6 CO2
If I count right, Ethanol only needs 5 oxygen to burn completely with one free hydrogen left over. The benzene needs 15 oxygen to burn completely. The ethanol burns leaner and produces a lot less power per molecule.
What that means is (1) more of the smaller molecule will evaporate thru rubber lines unless one has the Gates Barricade. (2) your fuel mileage will be less (3) Alcohol can absorb water so some unscrupulous folks who work there can fill their cars for free, add that many gallons of water to the big tanks and still pump the same number of gallons of gas but it has a higher water content.*
*At 60F 3.8 teaspoons of water can be dissolved into a gallon of E10 gasoline without it separating out. In a station's 20,000 gallon tank that is 3.8 teaspoons X 20,000 gallons = 76,000 teaspoons of water. 76,000 / 768 teaspoons per gallon = 99 gallons of water that can be added to the 20,000 gallons which will dissolve into the E10.
We see about a 5 - 7% reduction in mileage between 100% gasoline and E10 when we are on vacation. When we hit a station that has probably been cut with water we see mileage drop significantly. The plugs are cleaner today that 30 years ago. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin
Last edited by SGKent on Thu May 19, 2016 8:48 am; edited 2 times in total |
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Amskeptic Samba Member
Joined: October 18, 2002 Posts: 8568 Location: All Across The Country
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Posted: Thu May 19, 2016 8:43 am Post subject: Re: Ethanol and our FI engines? |
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DougB wrote: |
Around me it's nearly impossible to find pure gasoline, and everything has 10% Ethanol.
Just wondering how this might affect our engines, e.g. if it went up to E15.
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I have not had any issues with ethanol over the past 18,000 gallons or so.
The only recommendation I can come up with is keep a close eye on the condition of your fuel hoses if they are not spefically designed for high ethanol concentrations, as they seem to age more quickly.
Other than that, I hardly notice the loss of combustion efficiency., and I appreciate the cleaner spark plugs.
Colin _________________ www.itinerant-air-cooled.com |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50336
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Posted: Thu May 19, 2016 12:04 pm Post subject: Re: Ethanol and our FI engines? |
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SGKent wrote: |
The plugs are cleaner today that 30 years ago. |
The plugs are certainly cleaner than they were and there are fewer carbon deposits inside the combustion chambers and up into the intake manifold to the locations of the injectors, don't know if this is due to ethanol or other changes in the fuel. The one big negative to ethanol laced fuel is that if you let your rig sit for prolonged periods, when you start running it again you can get a build up on you valve stems that can cause the stems to hang up in the guides and thus cause engine damaging interference between the valves and the pistons. |
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