E 85 fuel in a High Compression Engine

[Garys1969RR]

Was wondering if anyone has tried using E 85 fuel in their engine. I heard about a guy at the local drag strip that runs it in a 451 and his 1/4 mile times are around 11.5 sec et. And this is at 5400 feet! I have a 451 at 12.5 to 1 C/R and have access to the Holley metering blocks that allow use of this fuel. It is rated at 105 octane. The Holley guy that supplies these says that the engine will produce as much power with E 85 (when properly tuned) as it will on Race fuel. Since it is readily available in my area, and is less cost than regular gas, I would like to try it out. I ran it in an old Toyota that was built to run on gasoline for awhile, and no problems. But the MPG dropped. Any first hand experience is appreciated. :eusa_think:

 

[RCAddict]

Quick Fuel & a bunch of other carb companies are selling E=85 carbs
I've read some posts on another site where the racers are using E-85 with success.
I went to a Pontiac Nationals event & there was a guy there that I watched fillup with E-85 with my own eyes at the station outside the track
The car ran a 11.30 1/4 mile on the whitewall Walmart tires that he drove to the track with & 9.70 1/4 mile on 10" Drag Radial
His 472" Pontiac in his Catalina he said had 14 to 1 compression & he said that he drives it to work daily

 

[67 B-body]

I've been told they run considerably cooler too!!! I would love to try it, but don't have the extra coin to spend on a test right now..

 

[Meep-Meep]

If you want to get the most out of E85 you must raise the compression. You will also use more fuel in the process but if making power is the goal then have at it. E85 as I understand it is corrosive to some fuel system parts so do some research on that. You can probably get away with running a tank then refilling with gas after to flush it out.

 

[Garys1969RR]

How high of C/R are you talking about, Meep Meep? Like 14 to 1? I'm running 12.5 to 1

 

[RustyRatRod]

Just remember the air fuel ratio is a lot different. But then....you probably ain't lookin for mileage. lol

 

[Garys1969RR]

No, just lookin for $3.00 a gallon fuel as opposed to $7.50 a gallon. Then I could cruise more in it. I knew this would be an issue when I built the motor. And I do like to experiment with different combinations. So if I can get good power with E 85, then will use that for awhile, see what kind of drivability I get. I understand that MPG drops with this fuel, was hoping for more miles driven per dollar spent! Lol Guess the best way to find out is to try it. Will post results here in the future.

 

[Garys1969RR]

Right now getting about 12 miles per gallon. At 7.50 a gallon, that equals .63 cents a mile. Even with Av gas at 5.20 a gallon, comes to .43 cents a mile. If I get 10 MPG with E 85, that comes to .30 a mile! So will do some experimenting and see what actual real world results are.

 

[67 B-body]

I used to run a fuel conditioner in the drum of alchohol for our Late Model "dirt track" race car, and the stock car too.... It was supposed to aid in preventing corrosion and also provide a lubricant for that dry alchohol...... I wonder if it would work in E-85 fuel?

 

[lxmodguy]

There is an awful lot of mis-information out there about E85. I am not the foremost expert. I done a lot of research and tuned my fair share of e85 cars. E85carbs has a lot of good info.

You dont have to run higher compression to take advantage of e85. You can run more timing and make more power. It is especially good for boosted engines as it does run significantly cooler than gas and the higher octane keeps detonation away. It does roughly take 30% more e85 that it would if you ran gas. stoich ratio is different by about that same 30%. Do your research. e85 is an amazing fuel. As long as your fuel pump, filters, and carb are setup for e85 it has minimal effect on equipment longevity. New gen hemi's can run e85 with an injector change in most cases.

 

[Garys1969RR]

So main jet size increases by 30%, and more idle screw opening. Does the power valve channel restriction also need to be opened up by 30%? I would think so. This is with a Holley carb being used. What else has to be changed far as carburetion goes?

 

[Meep-Meep]

How high of C/R are you talking about, Meep Meep? Like 14 to 1? I'm running 12.5 to 1

I'm no E85 expert but the alcohol fuels seem to respond well to compression. 12.5:1 is a nice number but there are people running 14:1 in pure race engines. I'd keep it as is and tune around it for the most power.

It's good you did the math about fuel usage. I was wondering the same thing (then saw your replay) because you will use more fuel to get the job done. Now you have me thinking... E85 is not falling out of the sky in my area but I bet I can find some if I look.

 

[egrand1508]

There is an awful lot of mis-information out there about E85. I am not the foremost expert. I done a lot of research and tuned my fair share of e85 cars. E85carbs has a lot of good info.

You dont have to run higher compression to take advantage of e85. You can run more timing and make more power. It is especially good for boosted engines as it does run significantly cooler than gas and the higher octane keeps detonation away. It does roughly take 30% more e85 that it would if you ran gas. stoich ratio is different by about that same 30%. Do your research. e85 is an amazing fuel. As long as your fuel pump, filters, and carb are setup for e85 it has minimal effect on equipment longevity. New gen hemi's can run e85 with an injector change in most cases.

Funny thing about E85 is that it is not always 85% ethanol. It can be anywhere between 51% and 85% and vary from station to station. It can change with the time of year and the price of ethanol. So, if you're trying to fine tune for E85 you may not always get consistant mileage or results.

Ethanol is just another name for denatured alcohol, which is a solvent/parts cleaner/paint thinner. It will eventually eat up rubber and aluminum. So, you have to make sure your fuel system is compatible.

I have a Flex-fuel car and have tried E85 a few times. It does have a very noticeable kick in the pants for perfomance. However, my normal average mileage is 28-30 mpg with E10. Each time I used E85 it went down to 22-23 mpg. That is about a 20-25% drop. Regular E10 gas here is about $3.39 a gallon. Even at 20% that is 68 cents, or $2.71 a gallon to be equal. I checked at the local station tonight and E85 was $3.06. That is the typical difference. It is not cost effective for daily driving.

 

[Mesopic]

guy i know used to build/race evo's. Ran them on e85, he always drained the tank after each race since it so corrosive he said drain it or buy a new one.

 

[Garys1969RR]

Alot of good info online about E 85, including where to get it. I found some stations close by I didn't know they had it. Definitely worth pursuing this remarkable alternative to high cost race fuels.

 

[Garys1969RR]

Yes, Meep Meep I don't plan any more major engine work right now. Just tuning for E 85. I understand that total timing may need to be advanced 3-4 degrees. Running 36 total with 100 Sunoco at this time. 12.5 to 1 C/R. Doesn't ping at all until the engine starts to run warmer on a hot day. Then only under full power about 3500 to 4500 RPM, I have noticed a barely audible ping, and I immediately let up the throttle. Thanks for all the good info every body!

 

[lxmodguy]

The quality of e85 does vary a bit from station to station. I would agree it isn't the best daily driver fuel. It makes great race gas for half the price and the engine runs a lot cooler.

 

[Meep-Meep]

Yes, Meep Meep I don't plan any more major engine work right now. Just tuning for E 85. I understand that total timing may need to be advanced 3-4 degrees. Running 36 total with 100 Sunoco at this time. 12.5 to 1 C/R. Doesn't ping at all until the engine starts to run warmer on a hot day. Then only under full power about 3500 to 4500 RPM, I have noticed a barely audible ping, and I immediately let up the throttle. Thanks for all the good info every body!

Just for the sake of gathering data, what is your cranking compression? Did you CC it and arrive at 12.5:1 or educated guess?

 

[Garys1969RR]

My compression as checked with a gauge is 180 to 195 on all cylinders. But my gauge seems to be reading on the low side. I computed the C/R with the Keith Black Pistons online calculator, before I built the engine. These are the specifications I used. Bore: 4.3750 Stroke 3.75 Gasket diam 4.375 Gasket thickness .020 Chrysler Steel shim, Ross dome pistons P/N 99500, with 14 cc dome. Pistons at .017 below deck. 906 heads cut .010. Didn't cc the chambers, but at 88 cc C/R computes at 12.11 to 1. At 85 cc it is 12.53 to 1. So this is an educated guess. Would like to go to Stealth or Eddy heads some day, at 84 cc chambers. Plus would have better squish/quench. Thats how I came up with 12.5 to 1 C/R.

 

[Garys1969RR]

Also I live in the rarified air of Lakewood, Colorado. About 5400 feet MSL. Would not have built that kind of C/R into a street engine if I was running it below about 2000 to 2500 feet elevation.