E85Forum.com

Volvo-Berti · Joined: 24 Oct 2005 Posts: 16 Location: Germany

hi folks,

does anyone know if the temp in the engine using ethanol is higher or lower than driving pure gas?

my information is that ethanol burns at a higher temp, but the water in it cools the engine. will this cause a permanent driving below the optimal engine water temperatures??

thx a lot

regards

Volvo-Berti, apologizing for the english again Embarassed

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greets
Berti

BURNALCOHOL · Joined: 19 Oct 2005 Posts: 50 Location: Raymond,NE

Volvo-Berti,
Only if the fuel air mixtures are set too lean will the engine run hot on ethanol. Ethanol (without water in it) at the right mixture will burn cooler than regular gasoline. Some web sights I have looked at even suggest a hotter thermostat to help the ethanol burn better.

Jeremy Nicholls
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Jeremy Nicholls

specialgreen · Posted: Mon Nov 07, 2005 11:01 pm Post subject:

I have to wonder about the "hotter thermostat". Until the engine reaches recommended operating temperature, then the thermostat should just stay fully closed. Moving to a hotter thermostat should not get the temperature up to operating temperature faster; it should just cause the engine to stabilize at a higher tempreature than recommended (for gasoline).

Not that thermostats have ever done what they are supposed to do. They are very fickle. Also, running the engine hotter than normal may make the intake manifold hotter, which will have a positive effect on getting a good burn. But there are more direct ways to get the intake manifold hotter.

hotrod · Joined: 19 Apr 2005 Posts: 872 Location: Colorado

My data logging showed the engine ran about 10-15 degrees cooler (coolant temp) all else being equal on 100% E85 vs Gasoline. I run a 180 deg F. thermostat in the winter when the stock thermostat is a 172 deg F. It makes a small but noticable difference in drivablility during warm up and gives me slightly better heater output. In very cold weather I also block off most of my radiator opening like the big trucks do to help the engine get up to normal operation temp. As noted in other threads one of the suspected causes of increased engine wear noted in early alcohol fuel tests were due to build up of formic acid in the oil. Pure formic acid has a boiling point of 100.8 deg C so if you consistantly get your oil up to boiling water temperatures you will have no acid build up issues. People who tend to do a lot of short trip commutes and errands with their car should take care to be sure the engine gets up to full temp regularly to keep moisture and such cooked out of the oil.

Larry

Volvo-Berti · Joined: 24 Oct 2005 Posts: 16 Location: Germany

ah, i see

driving with ethanol (with or without water in it) could cause problems in cold weather times, because it needs more time to reach the optimal oil temp.
the more water is in, the slower the temp will rise. is that correct?

but this is in opposition to my investigations. the water temp is reaching the optimum a little bit faster as just running my car with gasoline only. Question

but i`ve never heard about building formic acid by oxidizing ethanol, only acetic acid. but any acid will not be good for my volvo Rolling Eyes

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greets
Berti

hotrod · Joined: 19 Apr 2005 Posts: 872 Location: Colorado

Engine temp behavior would be not be the same with your car and mine as they are probably running different Fuel Air mixtures. Your car may be running a bit leaner than mine was. I didn't see much difference in warm up time because the WRX warms up very quickly (quicker than any car I've ever owned), but I did notice that the coolant temp at highway cruise speeds were just a bit cooler.

Larry

Edi · Joined: 11 Sep 2005 Posts: 14 Location: Germany

In motor oils are alkaline additives inside for neutralizing acids. Therefore one can measure the base number from the oil in mg KOH pro ml oil. These additives are also detergents to clean and dissolve sludge and/or carbon deposits.

http://dc2.uni-bielefeld.de/dc2/auto/motoroel.htm (only in german language)

Thats also right, that ethanol is building only acetic acid, but in ethanol from plants is also very little bit methanol inside, so that formic acid can also be build. But I think these are very, very small amounts.

Volvo-Berti · Joined: 24 Oct 2005 Posts: 16 Location: Germany

@hotrod

at what speed did you recognize the little colder temp? as far as i know your speed limit is at 65mph, that means approx. 105kmh.

here in germany we do not have a speed limit at most of our highways, as you will know.

but this phenomenon you describe i did not see while driving 20 miles at a speed of 70 mph

@Edi
i didn`t know the source of my ethanol, i bought it in a big supermarket. the website of the producing company did not say anything about bio-ethanol. so i think my ethanol is not made of plants or any biological material.
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greets
Berti

Edi · Joined: 11 Sep 2005 Posts: 14 Location: Germany

Volvo-Berti · Joined: 24 Oct 2005 Posts: 16 Location: Germany