e85/alcohol friendly fuel system

[switchblade327]

I've done my searches here and on the 'net in general and I know this isn't first time e85 has come up here but the questions I have haven't really been covered.

The big debate seems to be how much modification is necessary to make your car run on e85 without corroding your fuel system or running like crap. Now if two different engineers in a previous thre couldn't agree on that, I won't expect a clear resolution to that one.

My situation is this: I'm setting up my bel air with an lt1 so I need a complete new fuel system *anyway*. And I want to be running the car for a long time so I'd like to make sure that at least the fuel system is 100% compatible with e85 or even pure ethanol. So rather then debate how severe the changes need to be in the fuel system, I want to know what every could agree is bulletproof alcohol-compatible fuel system; not just the minimum of what I'd have to modify. I want to know how the guys running methanol big blocks plumb their fuel systems and perhaps more importantly, where they get the parts to do it. I want to spend the extra now to make sure I'm still able to enjoy driving my car when gas is $10 a gallon.

I want overkill. Well, within financial reason.

I already know to avoid rubber, brass and aluminum and I plan to run stainless lines the whole car, leaving a section in the line to place the e85/gasoline sensor at a later date. A stainless tank is also in the plans but if there's another material for a tank or fuel cell that is *definitely* alcohol-resistant, I'd love to hear about it. Likewise, I need to find TPI fuel pump (preferably in tank) that is alcohol compatible.

I know this has been done for ages on race cars but I can't find much info on how these guys do it where they get the parts so I thought I'd pick the brains of all the smart people here.



Thanks in advance.

[BADVELLE]

I don't know why you are worried about E85. Until they figure out how to manufacuturer and transport this fuel that is cost efficient, you will never see if nationwide. Plus, I have read alot on the subject and if our natural resources are you main concern, great, but don't run it for fuel mileage, I just dont' buy it. If you are going to pay $1.00 less for this 85% ethanol fuel, but you generally burn alcohol v. regular gas at a 2:1 basis, I don't see the savings in economy. Anyway, I no I am no help here, just a rant, but I would not waste time nor money on this endeavour.

[switchblade327]

Well I don't have a crystal ball and I can't predict the future but I have done a lot of homework on e85 and I don't think it's quite that hopeless. But I'm not here to wave the flag of ethanol or debate a subject best left to scientists and engineers. That debate is all over the rest of the internet and other threads here anyway.

The point is if I'm replacing all my lines and tank anyway, what's the harm in spending a bit more to make it as future-proof and flexible as possible? I already know WHY I'm doing it. I just want to know HOW.

[RobM]

methanol is that 2:1 ratio.... ETHANOL with is in E85 is prettly close to gasoline, not to mention its wayyyy cheeper than race fual with the same octane. its a good thing for our hobby people

[EFI69Cam]

If the engine was built with the compression to take advantage of the 105 octane, the increased efficiency would make up for some of the difference in energy content. The problem with economy is because flex fuel vehicles are being built with gasoline friendly comp ratios.If there was a e85 station closer to my house I would not hesitate to swap the pistons in my 540 and run e85.

[Fuelie Fan]

Ethanol can be fun on an engine with higher compression ratio, but that will do little to save your economy. Also, Ethanol is "closer" to gasoline in A/F ratio than methanol, but I still wouldn't go so far as to call it "close"

stoich A/F of gasoline: 14.7
stoich A/F of E85: 9.8

difference: 33%

Effect on efficiency by raising compression ratio from 9 to 12: 5%

You're still down 25+%. As Rob said, the fun factor may warrant it on some applications, so if you want to go for it, the go for it!

You should use stainless or plastic fuel lines and probably the same for the tank. Check with your injector manufacturer for compatibility as well. When we ran our formula SAE car on E85, the o-rings that were alcohol compatible was a very common and cheap material, I think buna-N? It's been a while, sorry

[EFI69Cam]

Ethanol can be fun on an engine with higher compression ratio, but that will do little to save your economy. Also, Ethanol is "closer" to gasoline in A/F ratio than methanol, but I still wouldn't go so far as to call it "close"

stoich A/F of gasoline: 14.7
stoich A/F of E85: 9.8

difference: 33%

Effect on efficiency by raising compression ratio from 9 to 12: 5%

You're still down 25+%. As Rob said, the fun factor may warrant it on some applications, so if you want to go for it, the go for it!

You should use stainless or plastic fuel lines and probably the same for the tank. Check with your injector manufacturer for compatibility as well. When we ran our formula SAE car on E85, the o-rings that were alcohol compatible was a very common and cheap material, I think buna-N? It's been a while, sorry

One of the strategies used in OEM applications is to fatten the mixture before pulling timing when knock is detected. This is another benifit of E85, with its higher "octane" rating it does not cause the PCM to fatten the mixture.

Also if stioch of e85 was 9.8:1 the O2 sensors would not work for both fuels, I would think.

[bigkaboose]

I see lots of advantages they had a article on it in July Popular Hot Rodding. Be able to run 13:1 compression on the street and its cheaper than race fuel why not... Oh and it burns cleaner. It also stated that the octane can be as high as 113 thats all the technical info I can provide.

[MarkM66]

[switchblade327]

I know there are aftermarket kits for flex fuel setups but I don't think any are for sale in the US (Brazil has been running flex-fuel cars for the last 10-20 years, including retrofitted ones.) Apparently these use a seperate computer so they don't require changes to your pcm or o2 sensors. I think it works by having a switch that you flick depending on what's in the tanks; don't ask for details, I'm just regurgiating information.

Anyway, most of this has been discussed/debated before. I've already decided I'm going to build my car to consume alcohol (like father, like son). What hasn't is how to alcohol-proof an EFI fuel system (most specifically, the pump and the tank) and where to get the parts to do it. I know there are tons of race cars running methanol. There has to be some off-the-shelf parts to do this.

[Fuelie Fan]

Also if stioch of e85 was 9.8:1 the O2 sensors would not work for both fuels, I would think.

Sure it will. It's an oxygen sensor, not an A/F ratio sensor. When you're lean of stoichiometric, there's little or no oxygen and so the sensor reads low. When you're rich of that point, it reads high. Doesn't matter what the number associated with stoich is. Even widebands are only really oxygen concentration sensors, the manufacturers then overlay transfer functions so that the numbers are something that you're familiar with.

Switchblade, as i said, look into a stainless or plastic fuel tank. As for fuel pumps, you'll have to call manufacturers, but again it shouldn't be too hard.

[EFI69Cam]

Sure it will. It's an oxygen sensor, not an A/F ratio sensor. When you're lean of stoichiometric, there's little or no oxygen and so the sensor reads low. When you're rich of that point, it reads high. Doesn't matter what the number associated with stoich is. Even widebands are only really oxygen concentration sensors, the manufacturers then overlay transfer functions so that the numbers are something that you're familiar with.

Switchblade, as i said, look into a stainless or plastic fuel tank. As for fuel pumps, you'll have to call manufacturers, but again it shouldn't be too hard.

I realized that the sensor reads oxygen and would not care what fuel or intial mixture little while after writing that. Are you sure on the stoic mixture for e85?

[Fuelie Fan]

Yes. MarkM66's post gives some confirmation. I calculated it from data provided in Heywood, Internal Combustion Engine Fundamentals

[switchblade327]

Thanks Fuelie Fan. I found yesterday that Holley has a whole line of alcohol ready pumps and regulators. I was hoping for an in tank setup but it looks like an in-line pump is going to be my best bet to do this without a lot of expensive, custom work.

[Kenova]

Thanks Fuelie Fan. I found yesterday that Holley has a whole line of alcohol ready pumps and regulators. I was hoping for an in tank setup but it looks like an in-line pump is going to be my best bet to do this without a lot of expensive, custom work.

General Motors has been putting E85 compatible fuel pumps in their Flex-Fuel trucks for a couple of years now. You may be able to use one of them.
The Flex-Fuel fuel tanks are some sort of plastic, but the plastic fuel rails have been replaced with stainless steel. The oxygen sensors used on the Flex-Fuel engines are the same as the gasoline only engines.
Ken

[switchblade327]

I called Holley the other day and it turns out they don't have any alcohol ready pumps for EFI. They referred me to Aeromotive Inc and I talked to one of their techs and he suggested which of their parts I could use. Now I just need to sort out my tank or fuel cell and I should be set!