Ehtanol Fuel vs. Pure Fuel

[jsawduste]

Michigan like most states runs 10% ethanol at the pump. No matter what grade it all has 10%.

Doing a bit of digging I found pure-gas.com that lists stations that sell non ethanol laced fuel. Lucky because of my proximity to the lakes means there is quite a few Marinas that sell straight gas. Mostly 90-92 Octane and about .75 to a buck more per gallon. Problem is that the boat docks/pumps don`t reach the parking lot. So a fuel caddy or a bunch of 5 gallon cans would be the options. Not real practical for normal usage.

Bit more digging and I stumbled on a Clark station about 15 miles from home that has actual pumps you drive up to. About .20 more a gallon then premium and 91 Octane. Filled up with just shy of 10 gallons in a 15 gallon tank. Roughly a 33% mixture.

Have driven about 30 miles thus far and the difference in performance is simply amazing. A/F ratios are running a bit richer especially in open loop. Pulls down low harder and really comes alive when up on the cam. Took a couple of my daughters to dinner and let the stroker stretch its legs a bit. Both the girls were asking me what I had done to the Jeep as it has never pulled so hard.

About this time last year I ran a series of dyno pulls with the standard Mobil 93 octane ethanol fuel. Going to put it back on the rollers but this time with a tank of ethanol free fuel. If the butt dyno is any indication we ought to see some pretty good gains.

Searching and getting edumacated about ethanol fuel has convinced me that it is nasty stuff. Not only to performance but the fuel system as a whole. It would be worth your time to get a grasp on what ethanol fuel is. The additives that are advertised as cure all`s and the corrosive properties of this fuel. Lot`s of good information here http://www.fuel-testers.com/index.html but that site is only the tip of the iceberg.

[SilverXJ]

Yah, ethanol is crap for an engine not built for it. And when I say build for it, and engine with high compression to utilize E85. I usually try to avoid it just because if its corrosive effects on the fuel system. There is a Pure station near me that I usually fill up at. Its about .20 more expensive.

[turbostroker]

I have run my first Engine on Ethanol for 4 year and then I dissamble it, the Engine was like new no grime or soot in the chambers and cylinderhead, no not normal wear outs. The bad reputation Ethanol got is just for the people who mix pure fuel and ethanol because then the Engine go lean and at abnormal work temp. Pure Ethanol burns cooler and have higher octan soo it is a perfekt race fuel but then you mix fuel and ethanol the Engine go lean and the fuel stands for the heat. My new stroker Engine runs on Ethanol, CNG, HHO, and fuel, but every fuel have of course differnt fuel/air mixture. Soo I agree with SilverXj if you should run Ethanol (over 15% mixture/the most ECU kan adjust upp too that) build the Engine for it and too take advantage of Ethanol you should have higher compression ratio.

[Cheromaniac]

Filled up with just shy of 10 gallons in a 15 gallon tank. Roughly a 33% mixture.

Have driven about 30 miles thus far and the difference in performance is simply amazing. A/F ratios are running a bit richer especially in open loop. Pulls down low harder and really comes alive when up on the cam. Took a couple of my daughters to dinner and let the stroker stretch its legs a bit. Both the girls were asking me what I had done to the Jeep as it has never pulled so hard.

Ethanol has a higher octane rating (108 RON) than premium gasoline so is consequently more resistant to detonation, but the downside is that it produces about 1/3 less energy per gallon of fuel when burnt so power output is lower. To compensate, engines built to run on ethanol have much higher compression ratios.
You're still running a lower compression ratio designed for a pure gasoline engine so when you're running the E85 (or any other) blend, performance is reduced. I'd be interested to see the difference in your dyno results with pure premium gas.

Michigan like most states runs 10% ethanol at the pump. No matter what grade it all has 10%.

The use of bioethanol in fuel blends is becoming increasingly common to reduce air pollution and reduce our dependency on fossil fuels. A good thing provided that engines are designed to run on the blend but our dinosaur-age 4.0L engines (and their stroker derivatives) can't make the most efficient use of it without some modification.

[Landon]

Hi all,
No pure fuel here in Austin, it's all 10% ethanol. Would this be a case for a stroker with stock 4.0 pistons? Would that make the right compression ratio? Maybe a cam with a little more duration to bleed off the pressure?

[Cheromaniac]

Maybe a cam with a little more duration to bleed off the pressure?

Actually the opposite is what's needed. With ethanol you can run a higher cylinder pressure without detonation so you could build a modified poor man's stroker (IC944 pistons, 4.0L rods, stock cam) with the block deck shaved to zero deck clearance (quench height = 0.043" HG thickness) and a compression ratio of ~9.8:1.

[FlyinRyan]

I compensate for E10 in all of my calibrations.