[runn141]

does anyone know about this fuel yet? what are the requirements of older engines? lower compression? higher compression? and what octane rating is it?

[JerryMopar]

E 85 can be thrown in ANY older engine except for one problem, you have to replace all your rubber parts that get in contact with fuel with urthane rubber parts.(including carb) The reason being is that alchohol will swell up all your rubber hoses after awhile, and cause big leaks.

I know Alky is a very good octane booster. All the renew stations here have E10, E20, and E85, which have all different octane ratings

Jerry

[tnoftsger]

alcohol like compression, lots of it!!!!! 13-14:1 is good... you can run lower compression but you will loose power and mileage. Check out the lower mpg on flex fuel vehicles.Fuel Economy

Not to mention the rubber and aluminum problems like Jerry mentioned.

What is e85 going for around you, here in kentucky it is more expensive. More money and less fuel economy, i think i'll pass until someone gets the prices down.

[JerryMopar]

1.99/gallon here

[Gassman]

E85 can not be used in older engines without major jetting changes. It will take almost twice as much. I don't know how much the loss in power could be made up with more compression. E85 is about 105 octane.

[conestogaman]

To run alcohol in an old engine means the previously mentioned rubber part replacement and feeding it more fuel. With a carb, unless you can manually lean/enrich the fuel mixture (similar to an aircraft carb), you'll need to open up the main jet about 40%. This is something not done easily to enable you to sip gas one day and guzzle alcohol the next.

Also mentioned is that alcohol runs higher octane allowing for higher compression. This also is not something your engine can switch back and forth to on a per fill up basis.

Bottom line is that until there is an adjustable compression engine with a tunable carb/injection system to identify and feed 2 different fuels (or a mixture of both), you will have to set up an engine for either alcohol or gas/gasohol (up to 20% alcohol).

A gas engine 'may' run OK on alcohol, but it'd suck some serious fuel and deliver poor performance compared to gas. An alcohol engine (high compression) can run on gas, but then you'll need to control detonation driving up fuel costs.

Perhaps a supercharger that would 'not work' when feeding gasoline and 'come online' when feeding alcohol, could solve some of the compression problems, but who wants an engine with a supercharger that you couldn't use unless you ran alcohol?

To put it in perspective, an alcohol fed, small displacement, high compression engine can do the same work (horsepower) as a gasoline fed, big displacement, low compression gas engine. Trying to feed that big low compression gas engine alcohol without boosting the compression ratio is a waste of available power. On alcohol, the engine could do so much more!!

Another thing is that alcohol doesn't atomize as easily as gasoline when cold and just runs down the sides of the carb and intake. A converted gas engine, running on anything more than a 20% alcohol mix, will need a cold start device.

Simplest would be a windshield squirter plumbed into the top of the air cleaner shooting straight gasoline down the throat. I like the old VW bug plastic bottles that are pressurized by the spare tire instead of the 12v electric pump American ones that 'could' cause a spark and a fire.

Just my $0.02

[matt167]

I wish I could get E85. 102 Octane for less than 93 octane, why not. A guy on CHR has done variouse tests on BBF's built to run on E85 and there getting very good results with them, over 500 Hp. E85 would be great for street/strip cars, not nessasairly drivers. my '51 Chevy with it's 235 I6 has a comp ratio of 6.7:1 and it dosn't need any more than 87 octane but my '67 Falcon has a 200 I6 that will be turbocharged and have a dynamic comp ratio of 11.25:1, will run ok on 93 but higher would be better, in this case E85 would be better.

[runn141]

so 10.3 to 1 compression will be fine or will it need more? convert to steel braided fuel lines from rubber? will the carburetor need more jetting? would more ignition timing help? is there anything else?

[matt167]

Originally Posted by runn141

so 10.3 to 1 compression will be fine or will it need more? convert to steel braided fuel lines from rubber? will the carburetor need more jetting? would more ignition timing help? is there anything else?

you will have to fatten the jets and convert all gas exposed rubber components to eurethane rubber, you could run more advance because of the higher octane. unlike popular belife you don't need a high compression engine to run E85, it can run a high compression engine tho because it is 102 octane. 10.3:1, 8:1 wouldn't matter

[runn141]

what about the mechanical fuel pump?

[conestogaman]

unlike popular belife you don't need a high compression engine to run E85

I didn't say you 'needed' a high compression engine, only that it allows you to get more out of an alcohol fuel. If you are gonna feed an engine twice as much fuel, you might as well get the most out of that fuel.

Ideally, you would downsize your engine and bump up your compression so the HP figures are comparable. You'll get the same fuel mileage and power but you'll tailor your powerplant to the different fuel's properties.

The problem with alcohol is that it has less btu's than gasoline, so it doesn't provide the same power (everything else being equal) as the same engine on gasoline. It will support a heck of a lot of compression though allowing you to make a smaller engine work harder.

In my opinion, if you run a gas engine on alcohol without increasing compression, you are just wasting fuel and potential.

[meschnebly]

"Perhaps a supercharger that would 'not work' when feeding gasoline and 'come online' when feeding alcohol, could solve some of the compression problems, but who wants an engine with a supercharger that you couldn't use unless you ran alcohol?"

Mad Max is running one of those!

[xxllmm4]

This article was VERY interesting to me... they made 1000hp from a turbo charged mustang on E85. It was even more interesting that they claim only a 10-15% decrease in fuel economy http://www.turbomustangs.com/techarticles/e85dyno.php

Jordon

[conestogaman]

That is an interesting article. It looks like they race it occasionally but maybe in a casual affair (aka: street racing for $$$??). Why else would you keep it...

No gauges, no race seats, no cage. All plain jane stock stuff.

They did say 10-15% more fuel consumption, but further down they say the first thing they did was increase WOT fuel supply 40%...

The first thing we did was add 40% fuel to the fuel map under WOT. We also added about 20% fuel in part throttle areas. We were tuning using a regular gasoline wideband air fuel ratio of 14:1 at part throttle. On the dyno the car made the best and cleanest power at 12:1.

Also they give a brief description of the engine but no compression ratios...

Test Car
1995 Mustang GT street car, 331 cubic inch, custom twin turbo system with twin T70 p-trims w/ .58 AR, T56 tranny, solid roller: 242/236, .600 lift, AEM Engine Management System.
Fuel System: 3, 255lph Walbro in line fuel pumps, 160# injectors. We were tuning with an AEM wideband system using a standard gasoline AFR. We weren't using lamda or other multipliers, just gasoline AFR.
No alky, no nitrous, no ice on the intake, etc.

And hp was measured...

At 6 psi of boost and 35 degrees total timing the car made 575rwhp from 6000rpm until 7500rpm

Very impressive. Normally a turbo engine will be mild on compression, but building it to run E85 only may have prompted them to up it a bit over stock.

It makes me wonder...

But the original poster wanted to know about older cars. Chances are that it'd have a carb instead of injected and no turbos so pushing the CR would be a way to get more out of the engine without going all out race. This can be accomplished with a turbo, blower, or cylinder manipulation (aka: shaving the heads).

Also the carb will need the previously mentioned rubber item changes, frequent fuel filter changes (due to the cleansing action of alcohol), and that cold start aid...

Good luck!

[Tech @ BG]

E-85 uses an A/F ratio of about 9:1 vs. 14.7 Stoich for a gasoline engine, or 6:1 for a methanol engine. This equates to requiring about 33% more fuel. On average most fuel injected vehicles loose about 20% of their fuel economy going from traditional Gasoline (E-10) to E-85 since they will run leaner. Most carbureted vehicles will loose about 25 to 30 % of their fuel economy depending on how well they are tuned.

Since the fuel volume requirements go up so substantially it’s not just a matter of putting larger jets in a carburetor in order to get it to run properly. The entire fuel curve (air bleeds, emulsion, etc.) needs to be recalibrated.

So should we use E-85 or not?

Pro’s it’s a little better for the environment. Yes we’re not burning as much fossil fuel while using it, so that is a good thing. However, you burn more of it so that 15% gas mixture is going to be higher, and it takes the burning of fossil fuels to turn it into a usable fuel from corn. So hey if you want to help the environment and don’t mind paying a little more at the pump then go for it!

Here’s the big advantage for us Hot Rodders… If you’ve got a car that is borderline on being able to run on pump gas, it is a heck of lot cheaper than buying real race gas or Av-Gas. But keep in mind it’s not the easiest stuff to find right now. You’re still looking at about 600 stations in the entire country that sell it. Way less that ½ of 1 % of all the gas stations in the country, so if you have to go to 200 gas stations to find 1 that has it, is it worth it to you?