Running ethanol

Jonny69

Jonny69

Jonny69

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Apart from the obvious change of jetting to swap from petrol to ethanol does one have to do anything else to the engine like run a special oil or anything? I know with methanol you have to use a special oil that doesn't soak up the methanol and change the fuel lines to something that isn't corroded away by methanol.

Before anyone asks, yes I am thinking along the lines of blown top alcohol engine on the street ;)
 
Sorry, missed the question there as well.

It's things like rubber hoses and perishable seals that are attacked normally, so stripping and rebuilding the carb/s/injectors with suitable seals would do the trick - if any are availiable for ethanol applications yet (RE the carbs, more...)

Blower seals too, if it's a draw-through application.

Timing probably need changing.
 
Oil won't need to be special for 100% ethanol. Ethanol boils at 78C so any that gets into the oil will simply evaporate.
 
BigglesPiP said:
It's not that you "have" to run higher compression, it's that you "can", the ethanol cools the combustion chamber rather well.
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Ethanol has a lot less energy per volume than petrol, so a higher compression ratio should be used to get the best power output from the fuel. It's not so much that you "can", but that you are not getting the most out of the fuel if you dont
 
Lower calorific value but higher Octane...So you can run higher boost (;)) and less ignition advance...

...I think...

*n
 
volospian said:
Ethanol has a lot less energy per volume than petrol, so a higher compression ratio should be used to get the best power output from the fuel. It's not so much that you "can", but that you are not getting the most out of the fuel if you dont
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Ethanol needs a lot more fuel in the combustion chamber as it burns lean if you do not alter the fuel flow. Approx 50% more.

So the energy content in the engine is similar and power output is. However 100% Ethanol has an octane of 129. So increasing the compression and running more ignition advance are options.

Increasing the compression helps the burn speed however it is not always required. Advancing the ignition will allow complete combustion.

The cooling effect of ethanol as it changes from a liquid to vapour state also helps improve engine performance
 
Yep I mean n/a I'll be looking at about 14:1 compression or more and I think you advance the ignition loads. Ultimately a smallblock will be able to run an 8/71 blower cranked up to the max if you use ethanol because it can take about 30:1 compression as far as I know. Would need some serious hadgaskets but imagine that on the street :D

Edit: Penski I ran my bike on 100% toulene and it bloody stinks :D
 
Simon said:
So the energy content in the engine is similar and power output is.
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Yes, as you have more volume. My comments were more based on the theory that if you kept the same amount of fuel, you would have to reduce the airflow to compensate, so "pound for pound" it produces less power (meaning that you need to use more fuel to obtain the same power, which is what you said)

However, running the much higher compression that Ethanol allows provides more power than a conventional compression ratio, which goes some way to making up for the drop in efficiency.

I suppose my point is about the MPG, not the specific power outputof an engine running ethanol, which makes it a fairly moot point anyway as I doubt Jonny is that fussed about economy :D
 
Jonny69 said:
Yep I mean n/a I'll be looking at about 14:1 compression or more and I think you advance the ignition loads. Ultimately a smallblock will be able to run an 8/71 blower cranked up to the max if you use ethanol because it can take about 30:1 compression as far as I know. Would need some serious hadgaskets but imagine that on the street :D

Edit: Penski I ran my bike on 100% toulene and it bloody stinks :D
Click to expand...

lol, sounds serious :D

Although is there a decent supply of ethanol in this country??
 
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