Not Logged In Log In   Sign Up   Points Leaders
Follow Us    11:05 PM

Message Forum - Read Message

Category: All Things Ethanol > Topics Add to favorite topics   Post new topicPost New Topic
Author Topic: What E85 good for? Back to Topics
Bonito

Champion Author
Dayton

Posts:19,396
Points:3,755,660
Joined:Jun 2004
Message Posted: Mar 24, 2007 8:17:31 PM

The stations I see are charging the same or more for E85, SO WHO WANTS IT? So we are using less oil -- big deal! E85 will not fly in the US unless we ARE REQUIRED to use it or IT'S CHEAPER!
REPLIES (newest first) Post a Reply
Profile Pic
jonjax14
All-Star Author Jacksonville

Posts:879
Points:174,770
Joined:Dec 2014
Message Posted: Apr 18, 2015 4:37:47 PM

ok
Profile Pic
nru
Champion Author Twin Cities

Posts:7,267
Points:1,876,125
Joined:Feb 2006
Message Posted: Apr 18, 2015 2:04:10 PM

Nope - a gallon of ethanol has 80k BTU and weighs 6.59 lb. A gallon of gas weighs less than ethanol (6-6.5lb) and has 115K BTU. the amount of air that can be delivered to most cars is limited by intake system (generally done In cubic feet per minute). If your math was correct my yellow car would be a much quicker car on ethanol than gas, it ain't (slightly, but it does not get a 30% gain in power by any means). Neither is anyone else who runs in the same class as me - sorry Soylent - defending ethanol with hooey is not a good thing. I support the idea, but you need to be careful running it. My yellow car last summer ran 1172 RWHP on ethanol and 1132 RWHP on 108 av gas. We have full control of fuel (pressure/pulse start/pulse width) and spark (timing/plug gap/voltage rise etc) - and these are the numbers for real and at full throttle - car can run either fuel with only computer and plug changes - as can others who race in my class and have very similar results. My intake is also fully capable of up to 2K hp - but I'm not a good enough driver to even handle what I have.

I would love it if we would engineer the U.S. Fleet for ethanol and thumb our noses at Putin and the terrorists, it's not there yet,

[Edited by: nru at 4/18/2015 2:06:30 PM EST]
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Apr 18, 2015 12:25:44 PM

you need to deliver about 50% more fuel (by weight or volume) to get the same power

Wrong, a pound of ethanol delivers about the same amount of hp as does a pound of gasoline. Because less air is required to burn the same amount of fuel more can be delivered through a fixed diameter intake. Thus, 30% more horse power in the same engine. (yes, different jets and or fuel pump pressure).

But, the same physics applies to passenger cars; at wide open throttle, more ethanol can be delivered than gasoline. So, more horsepower.
Profile Pic
nru
Champion Author Twin Cities

Posts:7,267
Points:1,876,125
Joined:Feb 2006
Message Posted: Apr 18, 2015 11:43:49 AM

And Soylent, in order to run ethanol/alcohol as a fuel, you need bigger injectors and I run higher fuel pressure - you need to deliver about 50% more fuel (by weight or volume) to get the same power - energy density by weight or volume is LESS in ethanol. It just has a higher octane, so I can run timing up. This generates higher cylinder pressures which get more power.
Profile Pic
nru
Champion Author Twin Cities

Posts:7,267
Points:1,876,125
Joined:Feb 2006
Message Posted: Apr 18, 2015 11:04:04 AM

Higher octane fuels produce more power in an engine because they allow more spark advance. Why some of us run alcohol in cars. Regular grade (89 octane or so) fuel will not develop more power with ethanol unless the octane rating is higher. It's just a matter of advance and cylinder pressure

Your horsepower can be made higher in a car with higher octane fuel. You cannot make more power with 89 octane gasoline than 89 octane gasahol. Just physics. If you were to buy 89 octane pure gas (no ethanol) and add 10% ethanol to it, you will get more power from an octane increase. Buying 89 octane gasahol means you are buying 87 octane gas with 10 percent ethanol most of the time. My mustang has been on the dyno many many times, and the difference between 108 octane av gas and 114 octane straight ethanol is about 3.3% on the rear wheels - higher octane allows you to get more power.

And there is nothing about density in your Tahoe Soylent. When your truck starts, the computer advances the spark until the knock sensors hit and then runs timing back a degree or so. Fuel pulse width in the injectors is controlled by your primary (before cat) oxygen sensor(s) - they just look to lean you out for fuel mileage. Unless you are actively programming your engines computer(s), you have no control over pulse width, the computer is just looking at the oxygen sensors to adjust mixture.

[Edited by: nru at 4/18/2015 11:07:10 AM EST]
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Apr 18, 2015 9:22:39 AM

" I have more power in the car also."

That's your imagination getting the best of you. Ethanol will and does produce more horsepower, not less. Partly because of the higher octane and, mostly, because the fuel air mixture requires less space per pound of fuel with ethanol. That means at full throttle, you get more fuel which translates to more horsepower. That's why alcohols, including ethanol, are used as racing fuels.

As far as mileage, I've been driving a route between eastern Iowa and the Chicago suburbs for almost 40 years: E10 one way regular or premium gasoline the other for most of that time. When we drive the same speed, take the same coffee stop, and wind conditions are the same, I've never seen a measurable difference between regular gasoline and E10. E85 is even too close to call.

Needless to say, in the 13 years we have owned our 2002 Tahoe, it has had a concentration of ethanol that has approached 85%. No fuel system issues.
Profile Pic
hopewell2005
Rookie Author Toronto

Posts:9
Points:3,020
Joined:Mar 2011
Message Posted: Apr 18, 2015 8:53:28 AM

true
Profile Pic
GuitarmanB4U
Rookie Author Orlando

Posts:4
Points:71,295
Joined:Mar 2007
Message Posted: Apr 18, 2015 5:54:47 AM

I am anti Ethanol, myself. It does harm the fuel system of you automobile. Mechanics and tuners and also automotive tech's have told me this. I also get better gas milage with non ethanol gas, which I call Pure Gas, then if I use the Corn Gas. I have more power in the car also. I only run Non Ethanol gas in mine and my wife's cars. It also saves me on mechanics bills in the future. But we all have our ideas and I'm glad that I again have this option and the state of Florida gave me back my option. Good luck on your decision with this subject.
Profile Pic
Alexi7
Champion Author Ohio

Posts:1,112
Points:26,990
Joined:Jul 2011
Message Posted: Apr 18, 2015 5:04:03 AM

Jayburt: Leno is an entertainer, hardly an authority on automotive engineering. And you're making the rest of us in NW Ohio look dim.
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Apr 16, 2015 9:39:58 AM

What's a "shrill"?
Profile Pic
sonbuule
Veteran Author Houston

Posts:419
Points:156,525
Joined:Jan 2015
Message Posted: Apr 16, 2015 9:10:07 AM

nothing
Profile Pic
Jayburt
Champion Author Toledo

Posts:4,471
Points:723,905
Joined:Jun 2009
Message Posted: Apr 16, 2015 4:36:48 AM

Just because he has been working on vehicles since he was young, and has owned and currently owned more than you or I will ever own, and has worked on them, he is a qualified source for knowledge about the effects (and damage) of ethanol. To say he's not is ludicrous and shows how desperate you shrills are to further your losing cause
Profile Pic
Alexi7
Champion Author Ohio

Posts:1,112
Points:26,990
Joined:Jul 2011
Message Posted: Apr 16, 2015 2:19:32 AM

Jay Leno, automotive engineer? Just because you collect cars doesn't mean you know anything about the engineering involved to produce one.
Profile Pic
Jayburt
Champion Author Toledo

Posts:4,471
Points:723,905
Joined:Jun 2009
Message Posted: Apr 16, 2015 1:10:20 AM

"...hanging your hat on an a poorly edited op-ed by a comedian." LOL, thats all you can come back with
You mean Jay Leno the guy who has worked on vehicles since he was 17 yrs. old? The guy who owns over 280 vehicles and is known for being hands on with them to the point he has his own car show? What a reach! And thanks for showing exactly what I stated in that comment ;)

Poorly edited piece? By autoweek, one of the most respected automobile publications in existence.. Jays line in the subheader of the article sums up what this thread is about--"Can't we just get rid of ethanol?"
Profile Pic
davidc2015
Rookie Author San Francisco

Posts:18
Points:10,250
Joined:Apr 2015
Message Posted: Apr 15, 2015 4:09:15 PM

hmmmm
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Apr 15, 2015 10:05:31 AM

"None of your bs will change that..and really your just making yourself look intelligently challenged by trying to."

You make this assertion after hanging your hat on an a poorly edited op-ed by a comedian. Sorry, that doesn't cut it.
Profile Pic
Jayburt
Champion Author Toledo

Posts:4,471
Points:723,905
Joined:Jun 2009
Message Posted: Apr 15, 2015 5:23:52 AM

"check the bottom of your article" = "Published in the May 2008 issue of Popular Mechanics."

March 2015 Jay Leno authors an article with the big bright headline of, and I quote

Jay Leno hates ethanol no matter what bs spin you try to put on it
he shows as a car owner of over 280 vehicles, and a mechanic who works on his own vehicles, that it is garbage.
None of your bs will change that..and really your just making yourself look intelligently challenged by trying to.
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Apr 14, 2015 10:02:33 AM

"Check the bottom of your article.."

IL: "Unlike gasoline, ethanol burns 100 percent, so it leaves behind no nasty residue. Without any leftover gunk to clog these key components, E85-powered engines tend to operate smoother and require less maintenance. Now you can see why Indy Cars run on E100 and the American Le Mans Series runs on E85. Ethanol helps clean up racing without sacrificing any performance. So ends the sermon for this issue.

By Jay Leno"

From the 2015 Autoweek article: "Last week, I went to start up one of my Duesenbergs. When I pulled out of the spot where it had been parked for about a month, I saw a huge pool of gas. I looked at it while it was running and saw gas just pouring out. “OK,I’ve got to buy another fuel regulator.” I pulled it out and opened it up. The fiber diaphragm was eaten right through."

And next to the quote; a picture of a torn up rubber impeller. Frist, the impeller is not a "diaphram". Second, the type of damage pictured would be from turning the impeller dry, as in letting the car sit for months at a time. Third, gasoline is more damaging to most rubber materials than ethanol.

However, if you have doubts, fill your Dusenbergs with premium gasoline. Shouldn't be much of an issue for the rest of the several hundred million cars on US highways. Really, I don't see establishing a national fuel standard, just to accomodate Jay Leno's dusenbergs.

[Edited by: SoylentGrain at 4/14/2015 10:03:37 AM EST]
Profile Pic
Alexi7
Champion Author Ohio

Posts:1,112
Points:26,990
Joined:Jul 2011
Message Posted: Apr 14, 2015 4:20:19 AM

Got 23.88 mpg in our 2014 Chevy Equinox on the highway. E-85 was $1.679 for an even 7 cents/mile. My '03 Acura CL gets better mileage(26.87), but that's on E-15 priced at $2.239, or 8.3 cents/mile.
Profile Pic
Jayburt
Champion Author Toledo

Posts:4,471
Points:723,905
Joined:Jun 2009
Message Posted: Apr 14, 2015 1:21:30 AM

so you bring a 2008 article where Jay showed one can be done "Published in the May 2008 issue of Popular Mechanics." Check the bottom of your article..
but want to ignore a March 2015 article where he clearly states http://autoweek.com/article/car-life/jay-leno-hates-ethanol, and not only says it causes fires using E10, but SHOWS pictures of the actual parts being ruined by gasohol? Ok.. your obvious turn of his Real feelings of it 7 yrs. later will convince everyone....smh

Although I love OnsiteComputers's take on it ;)

[Edited by: Jayburt at 4/14/2015 1:22:49 AM EST]
Profile Pic
nru
Champion Author Twin Cities

Posts:7,267
Points:1,876,125
Joined:Feb 2006
Message Posted: Apr 13, 2015 10:17:21 PM

I love the Leno car - and you can aftermarket most newer cars for straight ethanol or E-85. My yellow mustang (not street legal) cost me less than $1500 to modify for straight alcohol several years ago. It would run E-85 as well, but I have never tried

Iron heads, block
Hard coated intake manifold and pistons
Bigger injectors 160 versus 96 lb jobs
Viton seals in fuel system (fuel pump was already good for alcohol)
New regulator (higher fuel pressure required)
Computer reprogrammed

You still can't run your non-flex fuel vehicle on ethanol or E-85, and you need to make sure you take care of seals and aluminum if you convert, but it's good fuel if you know what you're doing. It's burning food, but denying terrorists and Putin funding.
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Apr 13, 2015 9:09:29 PM

"Jay Leno is talking about being forced to use e10, no where does he say he would use that 85crap."

Jay Leno's E85 powered 2006 Corvette Z06
Profile Pic
OnsiteComputers
Rookie Author Arkansas

Posts:43
Points:187,520
Joined:Jun 2011
Message Posted: Apr 13, 2015 7:30:50 PM

I get 900 miles to a gallon of Smirnoff on my bike

[Edited by: OnsiteComputers at 4/13/2015 7:31:25 PM EST]
Profile Pic
barryo62
Rookie Author Iowa

Posts:86
Points:2,490
Joined:Oct 2012
Message Posted: Apr 13, 2015 3:40:44 PM

Phpearso what is making ear corn higher priced?
Profile Pic
moxxor54
Veteran Author Missouri

Posts:416
Points:397,225
Joined:May 2012
Message Posted: Apr 13, 2015 8:37:11 AM

Corn is not for fuel, waste gas, poor gas mileage !
Profile Pic
phpearso
All-Star Author Indiana

Posts:530
Points:849,515
Joined:Mar 2004
Message Posted: Apr 13, 2015 2:19:19 AM

making ear corn higher priced.
Profile Pic
Jayburt
Champion Author Toledo

Posts:4,471
Points:723,905
Joined:Jun 2009
Message Posted: Apr 13, 2015 2:04:47 AM

rumbleseat you need to check your reading comprehension, Jay Leno is talking about being forced to use e10, no where does he say he would use that 85crap. Gasoline didn't make parts fail in 6-8 months so they could start fires..again read the article, and don't miss the pictures where they show closeups of the parts that e10 eats away.
Ethanol does not reduce any of the oil we buy from foreign countries, since we are exporting oil currently, and egas takes more volume to get the same distance and power so we use more.
Profile Pic
barryo62
Rookie Author Iowa

Posts:86
Points:2,490
Joined:Oct 2012
Message Posted: Apr 12, 2015 1:38:45 PM

SoylentGrain has a very good point about buying foreign oil and the oil money going to fund terrorist that hate us and want to kill us.
Profile Pic
rumbleseat
Champion Author Winnipeg

Posts:26,423
Points:3,926,960
Joined:Oct 2002
Message Posted: Apr 12, 2015 12:24:01 PM

"The problem with high ethanol content fuel is that most cars are not engineered for it."

So what? The use of E85 isn't forced on anybody! If your car isn't flex-fuel, and you don't want to try splas blending to see what level it will tolerate, you can ignore the E85 pump, it is as simple as that. My car isn't engineered for diesel, so I don't use it, but I don't worry about it. Just as the availability of diesel isn't a threat to me, the availability of E85 isn't a threat to you.

[Edited by: rumbleseat at 4/12/2015 12:32:36 PM EST]
Profile Pic
nru
Champion Author Twin Cities

Posts:7,267
Points:1,876,125
Joined:Feb 2006
Message Posted: Apr 12, 2015 11:46:58 AM

The problem with high ethanol content fuel is that most cars are not engineered for it. The materials have been chosen to accommodate a gasoline fuel in the past, and are starting to be better for ethanol, but unless you purchase a flex fuel vehicle, most warranties are rendered invalid with use of E-85. This will change, but I run straight gasoline in my 1975 and 1961 vehicles - the others run on E-10 fine.
Profile Pic
rumbleseat
Champion Author Winnipeg

Posts:26,423
Points:3,926,960
Joined:Oct 2002
Message Posted: Apr 12, 2015 11:31:22 AM

If one fills up an older vehicle with E85, without experimenting and carefully working up to what the vehicle can handle, whatever happens is his/her fault. Stupid is as stupid does.
"Its good for fires in your older vehicles,"
Gasoline has burned up a lot of vehicles.
Profile Pic
redhornet
Champion Author Minnesota

Posts:3,342
Points:1,604,240
Joined:Dec 2009
Message Posted: Apr 12, 2015 11:23:12 AM

It makes America strong and it is cheap to buy $1.44
Profile Pic
nru
Champion Author Twin Cities

Posts:7,267
Points:1,876,125
Joined:Feb 2006
Message Posted: Apr 12, 2015 11:04:52 AM

Soylent -,they fund putin as well
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Apr 12, 2015 10:01:57 AM

"As one of Adolf Hitler's closest associates and most devoted followers, he was known for his zealous orations and deep and virulent antisemitism, which led to his strongly supporting the extermination of the Jews when the Nazi leadership developed their "Final Solution""

Have you really thought of what your oil dollars are going towards? Iran, ISIS, and most of the other "states" that are motivated by extermination of Jews are funded by oil. When you fill your tank with ethanol, that money benefits US citizens and keeps funds out of the hands of muslim religious fanatics who are determined to exterminate Jews and US citizens.
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Apr 12, 2015 9:30:52 AM

"I believe that you don't understand what you are saying. "

Come on. you know hat he is talking about: repeating baseless lies.

Being terminally politically correct is much more offensive, to me, than referencing a socialist dictator's technique. Masking ignorance through political correctness is of no value to anyone.
Profile Pic
MikeCapeCoral
Champion Author Cape Coral

Posts:5,791
Points:1,316,215
Joined:Feb 2012
Message Posted: Apr 12, 2015 12:24:51 AM

I tried two tanks in my Flex Fuel vehicle. Very poor mileage.
Profile Pic
PhilnTX
All-Star Author Dallas

Posts:894
Points:1,120,385
Joined:Sep 2011
Message Posted: Apr 10, 2015 10:51:42 AM

"Goldseeker" Are you implying that people posting on this forum are like Goebbels?

As one of Adolf Hitler's closest associates and most devoted followers, he was known for his zealous orations and deep and virulent antisemitism, which led to his strongly supporting the extermination of the Jews when the Nazi leadership developed their "Final Solution".

I believe that you don't understand what you are saying.
Profile Pic
goldseeker
Champion Author West Virginia

Posts:23,991
Points:3,610,055
Joined:Sep 2005
Message Posted: Apr 10, 2015 2:12:35 AM

Joseph Goebell would be proud of a lot of the folks in here.
Profile Pic
Jayburt
Champion Author Toledo

Posts:4,471
Points:723,905
Joined:Jun 2009
Message Posted: Apr 10, 2015 1:04:18 AM

actually rumbleseat Mininana added much more than you did...
Its good for fires in your older vehicles, just like a guy who owns many and works on his own vehicles shows in this article where he gives his opinion on the very question of this thread.
Unbelievable gold that your still spreading your bull all over this forum, like anyone takes anything you have seriously after so many have shown you to be wrong on every aspect of the conversations. All that fact everyone has put in and you still spew nothing but bs,it must be terrible to have no soul.

[Edited by: Jayburt at 4/10/2015 1:06:27 AM EST]
Profile Pic
rumbleseat
Champion Author Winnipeg

Posts:26,423
Points:3,926,960
Joined:Oct 2002
Message Posted: Apr 9, 2015 5:50:01 PM

Mininana says: "to answer the question, it's good for mechanics..."

Not even the slightest attempt to provide a sensible contribution to the thread.
Profile Pic
goldseeker
Champion Author West Virginia

Posts:23,991
Points:3,610,055
Joined:Sep 2005
Message Posted: Apr 9, 2015 2:31:12 AM

No corrosion. No sham. E85 is great stuff.
Profile Pic
ray44512
All-Star Author Ohio

Posts:558
Points:250,440
Joined:May 2007
Message Posted: Apr 9, 2015 1:02:27 AM

Corrosion.
Profile Pic
f64
Rookie Author San Diego

Posts:75
Points:298,925
Joined:Oct 2013
Message Posted: Apr 8, 2015 4:34:46 AM

E-85 is a sham! It is good only for the oil companies that produce it and the politicians who are payed-off.
Profile Pic
Sneakers
Veteran Author Georgia

Posts:409
Points:63,530
Joined:Feb 2003
Message Posted: Mar 9, 2015 1:03:35 AM

To answer the question without the inevitable transportation/efficiency/food conflict debate: E85 is good for diversifying our fuel options, utilizing excess sugar beats/cane/corn and ... perhaps drinking(?) if you get the chemical separation process & associated costs down. I bet some Russian guy is dropping his antifreeze bottle and looking for an E85 pump right now.
Profile Pic
Mininana
Champion Author New York

Posts:1,185
Points:155,635
Joined:Dec 2014
Message Posted: Feb 28, 2015 11:20:27 AM

to answer the question, it's good for mechanics...
Profile Pic
krzysiek_ck
Champion Author Illinois

Posts:9,004
Points:1,500,510
Joined:Apr 2011
Message Posted: Feb 26, 2015 11:41:19 AM

wrote: "Mixed with octane 114 ethanol, & 84 octane base gasoline, to make octane 87 ethanol blends, toluene & xylene most certainly aren't in double digit percentages.....not even near. Even in 87 octane E0, toluene & xylene are still below double digits."

I provided information straight from Marathon 91 Recreational Gasoline Material Safety Data Sheet. Let's see the source of your wild claim.

By the way, Marathon completely disagrees with you. What a surprise. Marathon Regular Unleaded Gasoline MSDS

[Edited by: krzysiek_ck at 2/26/2015 11:45:07 AM EST]
Profile Pic
litesong
Sophomore Author Gary

Posts:173
Points:3,480
Joined:Mar 2012
Message Posted: Feb 25, 2015 9:34:30 PM

krzysiek koughed:
Toluene can be as high as 15% and Xylene as high as 10%.
///////
litesong wrote:
Mixed with octane 114 ethanol, & 84 octane base gasoline, to make octane 87 ethanol blends, toluene & xylene most certainly aren't in double digit percentages.....not even near. Even in 87 octane E0, toluene & xylene are still below double digits. Burned in gasoline engines designed to burn octane 87 E0, t & x produce minimal power output......kinda like.....ethanol.
Since krzysiek loves E10, E15 & probably E20, krzysiek has to be happy with even less toluene & xylene.

[Edited by: litesong at 2/25/2015 9:42:23 PM EST]
Profile Pic
nru
Champion Author Twin Cities

Posts:7,267
Points:1,876,125
Joined:Feb 2006
Message Posted: Feb 25, 2015 7:25:47 PM

Yes, combustion increases the temperature of the gases (energy input from the fuel - btu is a good measure) and results in a pressure increase - direct result of available energy from the fuel. You've argued yourself into a corner - if there is nothing about BTU's there in no available energy to increase the temperature and provide work.

If it had nothing to do with energy density of the fuel, there could be no work done with the motor - it's sciency stuff that you should darn well be aware of, tell me what supplies the energy if not the fuel (and the amount is energy density of the fuel related - you need more of a less energy dense fuel to get the same work out of a motor.

Simple application of the ideal gas law (no deriviitive ) results in zero work - or are you now going to tell us how to get work from a motor without putting in energy - you brought up that there is nothing about BTU's in the ideal gas law. If no fuel is available with enough BTU's, there can be no work Work is directly proportional to input energy - sorry just how a motor works
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Feb 25, 2015 5:30:52 PM

"No, and there is little relation to ideal gas law and a piston engine."

Tell that to the guys at NASA. I'm sure they would like to hear how to correct their website.
Profile Pic
nru
Champion Author Twin Cities

Posts:7,267
Points:1,876,125
Joined:Feb 2006
Message Posted: Feb 25, 2015 5:25:09 PM

No, and there is little relation to ideal gas law and a piston engine. I guess you are still better informed than all the engine guys in the world as to how they work though - and why all those people say the opposite of you
Profile Pic
SoylentGrain
Champion Author Illinois

Posts:1,696
Points:32,220
Joined:Nov 2012
Message Posted: Feb 25, 2015 4:51:54 PM

"you need the rise in something to give rise to pressure, and since the chamber is "sealed" n and R are fixed. So there is an inherent part of how an engine works that you are leaving out - back to why a motor will get more MPG from a high BTU fuel than a low BTU one."

Wrong. Pressure strives to be constant as volume of the cylinder varies. n is a variable based on pounds of fuel aspirated with variable airflow. Temperature is variable based on a combination of fuel mixture, timing, relative compression, and manifold pressure.

What you influence as you drive is n, the pounds of fuel injected into the engine by moving your foot on or off the accelerator determines the moles of combustion product within the cylinder at any given cycle of the piston.

What goes on behind the scenes is timing advance constantly moves varying degrees before top dead center. igniting the fuel sooner creates more pressure on the upstroke, increasing burn rate and temperature.

O2 and knock sensors regulate fuel mixture to provide as much air possible to increase temperature at tdc.

Higher relative compression and manifold pressure (turbocharging) also increase temperature by increasing pressure at tdc. But, of course, timing and fuel mixture would automatically dial back if these two are more aggressive.

Like I said, there aint no btus per gallon in the ideal gas law formulas.

The engine of almost every car on the road is programmed to prevent engine knock and maintain an exhaust gas temperature below a level that will burn valves. both ethanol and gasoline have far more energy than can be used by the volume of combustion gasses in the cylinder. regardless of how much energy is in a gallon of either substance, it gets wasted out the radiator and tailpipe.
Post a reply Back to Topics