millenniumtree
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| posted on 19/4/06 at 02:12 PM |
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Running on Alcohol
There's a push in the states to using E85 fuel (85% ethanol) I understand that top fuel dragsters and other racing cars also run methanol,
which is similar.
I'm interested in building my car so that it will be a 'flex fuel' vehicle. i.e. able to take both regular gasoline or alcohol.
Currently, in the states, E85 fuel is about 2/3 the price of petrol.
If I understand it correctly, hoses and tanks need to be changed to alcohol-compatible units (no aluminum, for example)
Has anyone had experience with converting a regular engine to alcohol for either racing or economic reasons?
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flak monkey
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| posted on 19/4/06 at 02:28 PM |
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The main difference is the huge octane rating difference. Ethanol has an octane rating of about 107RON (i say about, as it doesnt really have one).
Compare that to the octane rating of the normal pump petrol you have.
A 90% petrol, 10% ethanol mix has an octane rating of about 94RON. Regular US pump petrol is about 91RON, premium is about 95RON.
Alcohol has a higher octane number, but a lower energy content (about 19MJ/L compared to 29MJ/L for petrol).
David
Sera
http://www.motosera.com
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MikeR
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| posted on 19/4/06 at 03:13 PM |
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which means ???
(i'm guessing the car will need rejetting / timing to run on another fuel)
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NS Dev
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| posted on 19/4/06 at 03:24 PM |
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not experience but few bits of info. Yep, you need to change the fuel contacting bits of the fuel system, to what I don't know.
Very good fuel, very slow burning, detonation just is not an issue with it, but you need loads of ignition advance due to its slow properties.
It can also be run very rich without power drop off, which is just as well as you do need to throw a lot of it in! It's specific energy (or
whatever the scientific term is) is very low compared to petrol/gasoline.
Top fuellers do NOT use alcohol, they'd string you up from a tree for saying that! Thye use pure nitromethane (plus nitrous injection and
supercharger of course)
You don't want to be using nitro in a road car, not the safest thing, though you never know there may be a tax incentive
[Edited on 19/4/06 by NS Dev]
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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tks
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| posted on 19/4/06 at 03:41 PM |
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...
Well its seems to be true!
Link
In the dragster world they also add Nitromethane in the mixture to even more speedup the burning speed and to tune up the burning joules...
maybe i´m confused with the nitro.....will do a bit of home work first..sow don´t kill me...
Tks
p.s. you will need 2 mappings in your MCU (motor control unit) to be able to switch from one to another petrol.
offcourse you could self made an aftermarket edit box wich easyly add more time to the injector or stops the injection earlier...
for the timing the same..
[Edited on 19/4/06 by tks]
The above comments are always meant to be from the above persons perspective.
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flak monkey
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| posted on 19/4/06 at 03:46 PM |
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The RON number of alcohol is HIGHER than that of normal petrol. Ethanol is about 107, methanol about 110.
Top fuel dragsters run on a mix of methanol and nitro (nitromethane) and burn about a gallon per second at full tilt.
Both alcohols and nitro burn SLOWER than petrol.
To burn 0.5kg of nitro you only need 0.8kg of air. To burn 0.5kg of petrol you need about 7kg of air!
David
Sera
http://www.motosera.com
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tks
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| posted on 19/4/06 at 03:55 PM |
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..you googled right :D
How are the air figures for methanol and petrol?
in the end david because of the product needing less air, i think it expenses more heat!
else wy wouldn´t they run on petrol??
ok i see its because the higher octane number
Tks
[Edited on 19/4/06 by tks]
The above comments are always meant to be from the above persons perspective.
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flak monkey
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| posted on 19/4/06 at 03:59 PM |
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If i have remembered my chemistry right...
Nitro (nitromethane) already has 2 oxygen atoms in it to assist with the burn once some heat is there as the molecule breaks down when burning. So
less is needed from air, all you need is a bit of heat to get it going. Likewise alcohols have 1 oxygen atom and so will burn with less air than
petrol.
As for why drags run on nitro...
You only need a fraction of the air to burn nitro, so you can cram more nitro per stroke into the cylinder than you would be able to with petrol. It
may have a lower energy content, but if you pack 10times more in then you end up with more energy anyway!
David
[Edited on 19/4/06 by flak monkey]
Sera
http://www.motosera.com
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tks
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| posted on 19/4/06 at 04:10 PM |
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yeah
thats what i also conclude about the topic.
but i´m sure that nitro burns faster as petrol 6x times was told to me on discovery channel..
 we shall seee
Tks
The above comments are always meant to be from the above persons perspective.
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hector
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| posted on 19/4/06 at 04:51 PM |
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Title-"running on alcohol"!!!!!
I cant even walk on alcohol.....
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MikeR
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| posted on 19/4/06 at 05:53 PM |
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oh i can, the only problem is the next morning, i find lots of bruises and sore bits ........ occasionally a bit of hedge or something as well
never seems quite as funny either
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cossey
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| posted on 19/4/06 at 06:17 PM |
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the stoiciometric ratio for petrol is around 14.7 so 14.7 kg of air for 1kg of fuel. ethanol is 9 so only 9kg of air. so if you factor in this with
the less energy per kg of alcohol vs petrol you get alcohol ahead by about 4%. if you add in alcohols higher compression ability then it is alot
further ahead.
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Dale
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| posted on 19/4/06 at 06:42 PM |
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We build crown vics here (police cruisers ect) and some are made flex fuel for e85. I have been looking into it to see what is different on the car
than the staight gas. Different fuel seals , fuel pump (alcohol resistant - higher flow) lines ect. Different engine mapping but thats about it.
I am leaning on going to alcohol injection for cooling the air charge as well as the extra power. Running on homemade ethonal or methanol would be
a nice bonus as a straight fuel. Also you have to have a bigger tank I would suspect as you push almost twice the fuel through for pure
alcohol.
Dale
Thanks
Dale
my 14 and11 year old boys 22
and 19 now want to drive but have to be 25 before insurance will allow. Finally on the road
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NS Dev
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| posted on 19/4/06 at 11:15 PM |
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alcohol is a very kind fuel to use in turbo engines, lets you get away with a lot that petrol won't!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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millenniumtree
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| posted on 20/4/06 at 03:33 AM |
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Wow, this sounds like a real fun option, if all the specifics could be ironed out!
There are only 29 or so stations that sell E85 in the whole state of Wisconsin though, so being able to use regular petrol (up to 10% ethanol) would
be a requirement.
Might be an option to source all injectors, pumps, etc from a flex fuel vehicle and then locate a suitable tank, hoses, and a fancy computer to
control it all...
Might not be lo-cost though... Could get quite expensive. 
Still, could be quite fun with a turbo... Just run low boost on petrol and up the boost to something crazy when you fill up with alcohol.
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02GF74
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| posted on 20/4/06 at 07:06 AM |
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.... and you can always have an instant party if you carry some plastic hose with you..
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