E85Forum.com

Ripper · Joined: 28 Aug 2006 Posts: 1

I've been reading the forums and picking up bits here and there, but not being a professional mechanic or a hard core tuner ( rather, someone with resaonable mechanical knowledge....) and I was wondering if anyone knows of how to convert a normal fuel injected car to run on ethanol and gas, but explain it in a simple framework of tasks (step 1, step2, step3...etc ) and importantly *why*.

Anyone keen to put together a basic framework of what to do to allow an auto to run on both E85 AND normal gas?

I figure that way, if normal gas becomes super expensive, I can run on E85 sourced from many different spots ( maybe even a "home grown" version )
Wink

So any takers?

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

Just a quick breakdown.

1) If its a Honda, forget it.
2) Older cars need nearly everything replaced. Reconsider unless you know what you are doing.
3) Grab a magnet and see if it sticks to your fuel tank and fuel lines including under the car and in the engine bay. If it sticks, you have mild steel lines and tank otherwise, you need to swap that part out or do more research on that part for your car and its compatibility to ethanol.
4) Research the web and see if someone is selling a ECU programmer for your vehicle.
5) Get a Duty Cycle capable multimeter and hook it with your fuel injectors. Run the car at full throttle somewhere safe and try to get a good peak reading. This will give you an idea of how much injector your car is using and how much leeway you have. If you can add 30% to the duty cycle number and stay under 90% Injector Duty Cycle you can probably run E85 on that car without further changes.
5a) or Put 30% ethanol in your car.. Run it for 2 tanks. If everything is ok. Try upping it to 50%, run it for 2 tanks. Then go to 60% and see if your check engine light comes on. And so on. This may be the easiest option as it allows you to run cheaper fuel and not have to change anything.
6) Your options at this point are to hook up an adjustable fuel pressure regulator or go to larger injectors /w a larger fuel pump.
7) Or you can keep watching this forum until someone with more mechanical skill converts over a car like yours.
8 ) Give it up and go buy a certified flex fuel vehicle.

Due to quality control issues, it is not recommended that you run home grown ethanol in a car.

jdorff · Joined: 01 Aug 2006 Posts: 25 Location: RTP NC USA

The FlexTek E-85 approach is spelled out here: http://www.flextek.com/guide.htm

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

Or just read this:

http://forums.nasioc.com/forums/showthread.php?t=803341

ben · Joined: 30 Aug 2006 Posts: 1 Location: Rock Creek, MN

Hi guys,

I'm new here, but have been trying to find info on converting a carburetor engine to e85. Sounds like basically I need to up the jet sizes about 25%... and put steel or aluminum lines in. The engine I'm planning on converting is a 392 Chrysler hemi, and I'm wondering two additional things:

1. how high of a compression ratio can I run before detonation?
2. will a poly fuel tank work, or do I need a steel tank?

I'm building this for a truck that I'm building from scratch, so it's not a matter of replacing existing components, but buying e85 compatible, vs. standard stuff.

Also, does teflon (i.e. teflon tape for sealing fuel joints) deteriorate in e85?

Thanks,

Ben

specialgreen · Posted: Mon Sep 04, 2006 9:33 am Post subject:

HDPE (high density polyethylene) is fine, as is teflon. Some people have reported problems with incompatible gasket material on non-metal tanks. If you're assembling yourself, sticking with:
Buna-N, Neoprene, Polypropylene, nitrile, Viton or Teflon gaskets and hoses should be fine. You'll want to read http://e85forum.com/viewtopic.php?p=363#363 and http://e85forum.com/viewtopic.php?t=21

I've read here that compression of 12:1 should be fine for E-85, similar to that used with 105 octane race gas.

The numbers say 20%-30% extra fuel flow should be needed; with stock compression, on my motorcycle, I oversized the main jet diameter by 30%, and the idle jet/pilot by 37%. For some reason, the idle circuit needed more enlargement than the mains. I have not dyno'd or hooked to a tuner, so this is just a ballpark.

My fuel mileage is 83%-85% of what similar bikes get on gasoline, so for 9:1 compression, I think I'm pretty close. I believe that raising compression may require a smaller change to jetting. The folks here with turbos know more about that.

hotrod · Joined: 19 Apr 2005 Posts: 872 Location: Colorado

Ben:

I ran a built 392 (1958) Chrysler Hemi on the street in the late 1960's when pump premium fuel was about 100 octane. It had 10.25 :1 compression ratio in it and I had no problems at all with detonation.

I would be inclined to think you would be good up to about 12.5 and possibly 13:1 compression ratio based on that experience.

Of course part of that depends on your choice of cam shaft and ignition timing. With higher valve overlap you lose dynamic compression in the mid range rpms where detonation is most likely.

So a more agressive cam will allow you to run a higher compression ratio.
I've seen some sources that indicate ideal usable compression ratios for E85 are about 11:1 -- 14:1 but don't know anyone pushing the high end of that range on the street in a daily driver.

Teflon is safe with just about any chemical --- can't go wrong there, except the issue of getting very small shreds of teflon tape inside the lines. So be careful when you do the fittings.

Larry