Flex Fuel?

[Dyno247365]

I'm planning a big project with my Auto Club to build a car towards some type of charitable goal. I want to do a green car to get awareness out there for alternative fuels. Long story short, a Mobil 1 is providing E85 to flex fuel cars soon. What kind of engine uses flex fuel? Is there a conversion to build a gasoline/bio diesel/any engine not flex fuel to use E85? What are the requirements a flex fuel car needs? Thanks a lot!

[Steel]

flex fuel means it has to run on multiple fuels. Ford does a lot with those, i'm sure you can find one of their engines and us it.

I personally prefer biodiesel to ethanol. The compression otto cycle is inherently more efficient than that of gasoline, because first of all, those are very high compression motors ranging anywhere from 16:1 up to 22:1 (off the top of my head) and also the fact that since diesel is compression ignition, the air/fuel ratios vary wildly and isn't stuck in a set range as with gasoline or alcohol fired engines. For example, the stoich ratio for gasoline is 14.7:1 A/F, and with ethanol its ~6:1. You could run them leaner, but then they preignite, ping, and damage the engine, whereas a diesel ranges from (again off the top of my head) 8:1 at full load all the way to 80:1 at idle. There you can see that the engine is only using as much fuel as needed. When you see a diesel engine billowing out black smoke, that means that the fuel is not being completely burned in the cylinders. It's quite literally raw diesel coming out the tailpipe mixed with some soot. Now, some people modify their diesels for maximum power where the injectors dump tons and tons of fuel into the cylinders. Of course a lot of it doesn't get burned and henceforth the thing will be laying down a thick black cloud of smoke, but the purpose of running it so rich is that more fuel will be burned, its just that the cylinders don't have time to burn it all.

Anyway, back to the subject of green, i also feel that biodiesel is a much greener fuel source than ethanol production. With algae farm technology on the rise, and the inherent efficincies of the diesel engines, I think this is the best direction for the world to go in for future fuel needs. I don't know if biodiesel is available for you to use for Mobil's sake. In terms of building a car though, converting a regular diesel engine to a biodiesel engine (so long that its a relatively new engine, not something form 1967) is easy - just put in biodiesel in the tank, add some winterizing agent if its cold out, and drive. Heck, there are some diesels out there that run on waste vegetable oil. People quite literally take the used fryolator oil from McDonalds, filter it to get the bits of fries out, and do a couple of small modifications to the fuel injection system and BAM! you're car is running on fryolator oil. Which is free.

So, in the end, you should go do some research on your own into ethanol/biodiesel engines. You can obviously see my bias, so don't take my word as gospel, but keep your mind open. Both systems are viable alternatives, though i honestly believe that biodiesel is the way to go.

[Dyno247365]

There's something I just don't like about using fryoil...I can't put my finger on it, mostly because I've never seen anyone do it before, but it bothers me. I'll research what i can on both alternatives but in the meanwhile, how new do these Ford engines have to be? Any idea of cost?

[UncleBob]

its waaaay easier to make a butt load of power with E85. The very moment its availible in my area, I'm converting one of my turbo'd bikes to E85 and bumping the boost up to 25 psi

fry oil though, has simular limitations to diesel fuel. You can make power with it of course, but not as easily (IE cheaply)

[curtis73]

This is a subject of both mass confusion and mass misinformation.... which means Curtis is getting on a soapbox.

I personally LOVE biofuels of any kind. For any emissions they put out, they've first had to clean them from the air which means effectively zero net emissions. That sure beats dragging greasy hydrocarbons from the bowels of the earth and forcing them into the atmosphere. So, I must say, Dyno, a huge thank you for campaigning any vehicle that prevents humans from ignorantly digging hyrdrocarbons from below the ground and callously depositing them in the atmosphere. I fully laugh at how rich-types drive their gas SUVs while criticising the Mercedes biodiesel driver simply because the old Benz makes black smoke. More on that bullsh** below.

Now... you all know that I'm a diesel freak, but I'll try to remain unbiased here. I lean strongly toward the biodiesel for several reasons.

1- diesel is compression ignition which means a stable, safe fuel
2- compression ignition also means the elimination of the entire ignition system on an engine
3- diesel has a higher compression which translates to more BTUs being released from the fuel as BMEP pressure in the cylinder
4- as a result of #3, diesels typically return 30% or more greater MPG
5- biodiesel (or regular diesel for that matter) requires far less byproduct and fewer emissions to produce
6- biofuels could make use of the 34% of the agricultural waste that is normally discarded in the US. The stuff that is unfit for us to eat is prime fodder for two things: harvesting its oil for diesel, and fermenting it for ethanol.

I also have to disagree with UncleBob on one little point... diesel power is often so much cheaper than gas/ethanol. Ethanol is pretty much a wash in street engines. Methanol makes great power in race engines, but the 30% lower BTUs contained in ethanol compared to gasoline is balanced out by the 30% more fuel you have to burn for stoichiometric mixes. The bottom line is that diesel (in any form) has decidedly more BTUs per pound and per gallon than gasoline, methanol, or ethanol. I will agree that in forced induction the added octane equivalent of ethanol is very beneficial, but that opens up the debate of forced induction on spark igntion versus compresson ignition which is like comparing apples to farts. Both sides of the argument are equally valid, but you can't really make a decision on which is better. UncleBob is is wise enthusiast and I respect his knowledge, so I won't argue his apples against my farts... wait, what did I just say???

To convert a gas engine to ethanol takes considerable changes. Converting a diesel to bio requires... (get ready)... putting biodiesel in the tank, period. Its important to note that gasoline is a specifically regulated fuel consisting of federally regulated components. Diesel fuel (by law) is a class of fuels in which any fuel with the same energy and burn characteristics can exist, the government dictates. Kerosene, Jet-A fuel, and heating/fuel oil all have very similar BTU contents and all will operate very similarly in a diesel engine.

I personally feel that if you wish to campaign a mass-appeal embassador vehicle, you have two options:
1- campaign an ethanol/flex fuel vehicle that will appeal to the republican masses but has the lower environmentally beneficial impact. -or-
2- campaign the biodiesel vehicle which will have limited appeal due to americans' misinformation about diesel, but will have the greater environmentally beneficial impact.

I have stacks of factual information about it. If you want to chat, PM me and we'll talk outside of the subjective realm. The fact is, people see black smoke from modified diesels and assume that diesel is bad, but the truth is... that black stuff you see is 94% harmless by weight. Compare that to gasoline in which (as of 2006 EPA numbers) a full 84% of the invisible exhaust has been labeled either dangerous to the environment or to humans directly. The EPA and the CARB have successfully bowed to the dolphin-hugging lobbyists who have falsely ascribed danger to diesel emissions based on their appearance. The smartest bumper sticker I've seen is one that said, "just because you can see my exhaust doesn't make it bad. Just because I can't see yours doesn't make it good." The other fact that uneducated american drivers tend to overlook is that torque is what makes street-driven vehicles fun, but for 70+ years auto manufacturers have forced HP numbers down our throats. HP is an important number, but we are lead to believe that HP is the ultimate number in the retail wars. Diesels excel at torque production, MPG, and reliabillity, yet people buy advertised HP, exclusivity, and warranties. Its a huge factor in the import "horsepower per liter" argument that the young ones like to purport in the tuner scene. While I have the ultimate respect the specific output of any engine, the retail commercialism of the word "horsepower" has skewed the majority of the public who are willing to listen to retail advertisement without researching the actual facts before buying a car.

If you really want to look at specific engine output possibilities, look to diesel. A good comparison can be found in the last issue of Diesel Power Magazine. (http://www.dieselpowermag.com) They put two simiilar-displacement engines (one gas, one diesel, same make, same year) against each other. They spent equal dollar amounts on performance parts for both. After all the modifications the gas engine couldn't even make the same power or torque as the STOCK diesel engine made.

Put it this way. An LB7 Duramax diesel in a Chevy truck with an aftermarket air filter, aftermarket exhaust, and a simple programmer will make just shy of 1000 lb-ft of torque to the rear wheels with 6.6L. Compare that to the torquiest GM gas engine (8.1L) with the same modifications that can only muster about 400 lb-ft at the rear wheels. With the diesel, that's an incredible 250% of the torque with 19% less displacement. I'd say that's significant.

I'm truly dumbfounded by the reluctance of Americans to grasp the benefits of diesel. The new diesels (prepare yourself for a crazy thing..) actually emit cleaner air than they ingest. I'm not kidding. As of 2008 (some of them are already on the road), diesel engines will exhaust air that is cleaner than what they ingest. The EPA has manufacturers successfully jumping through ridiculous hoops to meet [what many feel are] insanely unrealistic emissions goals and STILL americans believe that diesel is a "dirty" fuel.

I challenge you with this, Dyno. If you are up to it, please help the environment and the education of us dumb humans and campaign the biodiesel. Both Ethanol and Biodiesel are pretty much equally friendly from the tailpipe, but biodiesel has such a more widely universal impact from the supply side. Biodiesel is a direct product, either by simply using waste vegetable oil recycled from food service or lubrication recovery, but also as an easy transesterification directly from first-use or recycled agricultural oil. Ethanol requires more processing and waste by-product.

Think of it like this... biodiesel can be made from recycled oil without consequence. Ethanol is a single-purpose fuel. Its made to burn. Biodiesel can be made from a product that has already been used, like the oil in a restaurant's fryer. Two uses with no degradation of the final product. Ethanol must be manufatured with complexity and can only be used once.

I know I get on a huge soapbo, but in all fairness there is equal validity in both alternate fuels. Diesel is what I see as the scientifically logical choice, but you can't grab society by the nuts and drag them to the end. Ethanol is an equally valid and if its a necessary step in the journey I embrace it. I would be ecstatic if every gas and diesel vehicle on the road today were replaced with ethanol and biodiesel... its just that the switch to biodiesel is incredibly simple compared to an entire manufacturing shift required for ethanol.

Ok, I promise... shutting up now. Counterpoints anyone? I'm sure MagicRat has something to say about this...

[curtis73]

Originally Posted by Dyno247365

What kind of engine uses flex fuel? Is there a conversion to build a gasoline/bio diesel/any engine not flex fuel to use E85? What are the requirements a flex fuel car needs? Thanks a lot!

To answer the questions (now that I'm off the soapbox )

Flex fuel usually is a term applied to an engine that burns either gasoline or ethanol. Here is a cut-and-paste from a website I found:

1 U.S. Gallon of gasoline contains 114,132 btu
1 U.S. Gallon of no. 2 diesel fuel contains 138,000 btu
1 U.S. Gallon of ethanol contains 76,000 btu
1 U.S. Gallon of methanol contains 56,800 btu
1 U.S. Gallon of propane contains 84,500 btu
1 U.S. Gallon of compressed natural gas contains 19,800 btu

when switching between gas and ethanol, two basic things need to happen: 1) the computer and sensors need to be capable of calibrating the mixture for both fuels, and capable of knowing which one is present. and 2) the physical components themselves need to be capable of delivering the proper amounts of fuel. Spark-ignition EFI engines are limited in their range of how much gross fuel the injectors can deliver at peak demand versus how accurately they can deliver small pulses of fuel at idle. Flex-fuel vehicles shine when they can deliver the required 30-ish% increase of flow at peak demand on Ethanol while being able to accurately meter small amounts of gasoline flow at idle when it requires precision during short injector pulses. The truth is, every fuel has ideal engine parameters. Designing an engine for two fuels of different BTUs requires compromises so that you have to shoot for the middle. Spark-ignition engines rely on very specific parameters. On the other hand compression ignition (diesel) engines get air and fuel. More air + more fuel = more power regardless of how many BTUs the fuel has. That means that diesel engines operate almost identically without any changes regardless of what fuel they burn. Designing a flex fuel engine requires engineering that even the major manufacturers have just begun to perfect. Designing a biodiesel engine has been done since 1920.. the same diesel engine will burn bio diesel. A spark-ignition flex-fuel engine means re-designing the engine. Making a biodiesel engiine means filling the tank with biodiesel.

So... (back on the soapbox) you could take a random diesel engine, fill the tank with Biodiesel, or a heated tank of corn, soy, hemp, olive, or nearly any other oil and burn it as-is with no sensors or computers since they all have similar BTU contents, and reap the benefits of compression ignition without consequence. Low on fuel? Stop at a fuel station with diesel... or at any grocery store or restaurant with oil to spare and refill your tank.

[UncleBob]

your point of cost is only important if you are only considering mpg. I was not refering to mpg, but IMO, if you're attempting to make as much power as cheaply as possible, you won't beat E85.

Granted, if you did a cost comparison over 200K miles, I have no doubt the bio-diesel would eventually win. Interesting, but defiinitely not important to me. Although I like to own things for a long time, the realistic time frame for such a toy, is not likely to see that many miles.

[curtis73]

Originally Posted by UncleBob

your point of cost is only important if you are only considering mpg. I was not refering to mpg, but IMO, if you're attempting to make as much power as cheaply as possible, you won't beat E85.

Respectfully disagree. Let's compare two trucks, both cost $20k. One is an LB7 6.6L duramax with 100k and the other is an 8.1L gas chevy with 50k. Spend $1000 on performance parts for each one; lets say, cold air intake, complete exhaust, and a power programmer. The LB7 will end up with nearly 1000 lb-ft to the wheels, while the 8.1L will probably only make 400 and change. The LB7 will put close to 500 hp to the rear wheels, but the 8.1 closer to 300. Given the same care, I would also venture that the duramax has another 200k in it, while the gas only another 150k at best. You also will get nearly double the MPG in the diesel, plus a higher resale value at the end. Plus you get those incredible gains without altering or affecting daily driving. You aren't altering the cam or flow qualities, so part throttle and idle characteristics remain unchanged.

Making diesel power is super simple and not very expensive. Here's a link to a 5.9L dodge 12v cummins that makes 2131 lb ft to the wheels on a dyno, daily driven.

Hard to believe, I know but it happens all the time. Many of those smokeless, quiet diesels beside you at the light are concealing 10-second, 7000-lb workhorses capable of towing and racing and you'd never know it.

I do agree with you though... E85 is alot cheaper to build. If I were setting out to build a vehicle that made cheap easy power, the E85 would also be my choice, but if I were campaigning a green ambassador vehicle, biodiesel is the clear winner for me.

[UncleBob]

not sure what the point of all the torque numbers are, thought we were talking about power.

None of your points address the cost of making a high-hp E85 engine. Although the work is more involved, its quite possible to make 1000+ hp for ~$2000. I bet the 2100+ ft/lb example makes just over 1000hp, and I also bet he has waaaay more into it.

[Steel]

I <3 curtis.

And remember, people buy HP but drive torque!

And making more power, if torque is equal mens that the engine is just turning faster. Lets not forgot who's been winning the LeMans recently

[UncleBob]

awww...steel, you don't want me to beat you up over that again, do you?

They are winning in lemans because the rules were massaged enough so they had a chance. Same with most race sanctions that want to attempt to get even competition when the playing field is uneven. Just like 2 strokes vs 4 strokes, twins vs 4 cylinders, NOS vs forced induction vs NA, etc. There has to be compromises to make it competitive.

[Dyno247365]

I don't know why...because curtis made such good points, but I'm still on the ethanol side. I can't be convinced and I have to decide for myself.

But, Peugeot is running a diesel LMP1 against the Audi, and they're the fastest cars to date in LeMans. Why are they diesels? I can't explain that one. Looks like I need to do more research, but diesel is interesting, but you're right, no one ever really liked it.

[curtis73]

There are many valid arguments for both spark ignition and compression ignition, but all I'm trying to do is remove some of the misinformation regarding diesel. Being diesel in America is a lot like being gay in Texas. People assume that is wrong, bad, satan, whatever... but the truth is, if you educate yourself about it, diesel is just as viable an option as any other fuel... and in my opinion since it has higher BTU, easier to make bio, and more simple/reliable construction, diesel is the clear street choice for me.

I can understand the rest of you being reluctant to come to the dark side

[UncleBob]

I like how you dismiss my points by indirectly calling me gay curt. The points I made were quite valid. Diesel definitely has its place. I personally don't think any and every situation demands it. I also think some people hype diesel way beyond reality in some areas

[curtis73]

Originally Posted by UncleBob

I like how you dismiss my points by indirectly calling me gay curt.

Not at all... I was merely making a comical analogy about how the misinformation purported by the masses leads to prejudice about a topic. I would never refer to an AF member like that

Your points are very valid and I always appreciate good discussions. Especially when the other guy is smarter, or at least smart enough to realize that I'm always right