what is needed to set up a 1981 corvette to run only E85?
I have a Holley double pumper if that helps.

 

Other than a misguided or misinformed attempt at saving the planet, there is no advantage to running on E85. The cost of replacing the entire fuel storage and delivery system to resist an 85% concentration of ethanol, plus the cost of engine recalibration to recoup the 30-33% drop in available energy will be staggering.

Since is E85 costs more to operate per volume than pure gas, you'll never make your money back.

Why bother?

 

100%

But if you really want to do it for no good reason, you need to get rid of the Holley gasoline carb and buy an alky carb. Then jet it down slightly and change bleeds, IFRs and PVCRs. A gasoline carb won't flow enough through the fuel circuit to work with 85% alcohol. To dial it in, you need to run the engine on an engine dyno to assure that mixtures and calibration changes end up correct across the power range. With the carb, fuel system mods, dyno time, and other issues, you're looking at at least a $2500 mod, with a resultant massive drop in fuel economy and power (unless you run custom pistons to take advantage of the higher "octane" of the 85%).

Lars

 

Due to corrosion issues, all new cars that run E85 use plastic or stainless fuel related parts. ie tank, lines. Check with holley, they can suggest the parts toi be replaced and new jetting. Jets will be larger so you're gas mileage will go down.
IMHO, it's only practical for high compression or boosted engine for the higher octane rating.

 

I'm still thinking very hard about going to E85 myself. Not for no good reason though! My 11.8 to 1 406 was happy on the 93 octane fuel available when the engine was in my 80 Vette. Since that time 93 octane fuel has almost disappeared here. I know of 1 BP station about 10 miles from me that has 93 in a dedicated pump. There are however E85 pumps in my neighborhood and about everywhere I ever go. Minnesota has the highest number of E85 pumps in the country. All the states surrounding me also have lots of pumps. We have had ethanol mandated in our fuel for decades in this part of the country. Not much of the sky is falling stuff I've heard about gasohol was ever a large problem. A lot of the problems people have had with ethanol is it's strong cleaning properties. It loosens up gum and dirt in the fuel system and you can imagine what that will do. Some accelerator pumps, didn't like it either. For the most part though, we didn't have much problems when the switch to gasohol came over 30 years ago.

E85 is not as corrosive as Methanol and there are a lot of racers in this part of the country that use it. The main thing is keeping the water out of it. It is hygroscopic, so it really likes to pull water out of the air. It is when water is introduced with the ethanol that corrosion becomes an issue. Care in setting up a venting system is needed to help minimize this. You also need to build a drain system so if the vehicle is going to sit for a while, you can quickly drain the E85 and pour in some gas to flush the system. I raced with nitromethane cut with methanol for years. Talk about corrosive! It makes ethanol look like a preservative, so I am well versed in dealing with the corrosive properties. I've talked with quite a few people running E85, as well as a couple of the E85 carb builders, and they say the corrosion is no where near what people claim or believe it is.

In my case I am replacing the complete fuel system in my car from tank to carb anyway, already have all the parts, so there is no added expense involved. I've built the added flow capacity into the system and everything is ethanol compatible.

As far as carbs, a methanol carb does not work as well as a gas carb modified for ethanol. All the passages in the metering blocks need to be drilled larger along with changes to the emulsion/air bleeds, PVC, idle feed, needle and seat, etc..., but not as large as a methanol carb needs. The boosters need to have at least a .180" fuel passage too.

For the difference in price of premium to E85 here, you can run the 20 to 30% loss in fuel mileage and still run the car about 15% cheaper per mile. E85 loves compression and boost. More power is available without the detonation problems of pump gas and the engines run much cooler with E85, and the great thing is the higher the compression is, the better the fuel mileage will be. E85 makes better bottom end and mid range power than gas and it cleans up the combustion chamber, valves and ports instead of depositing carbon like gasoline will. There are more upsides than downsides to E85. It does take some extra work and handling, but nothing ever comes for free!

 

I want to help save the seals so i can use their skin for my seats later down the road. I kid. 12:1 comp is the reason for the E85. All we have round these parts is 91* and lots of E85

 

$2500 was a little more than i planned to spend. I was ready for maybe half that. Recommend a Good N/A meth kit?

http://www.snowperformance.net/product.php?pk=77

 

i dont see an hygroscopic fuel as a problem in minnysoota as a problem in winter with mike and lars

 

ME 2.....

 

I don't drive my Vette in the Minnesota winters. The car will be put to sleep for the winter with gas in it's veins. I'm setting up the car to be able to quickly and neatly drain the fuel to change it for storage.

I don't see detonation from poor fuel as a good alternative and I'm not about to pay $10 a gallon for 100 octane unleaded from a gas station 25 miles away! I am not taking the compression out of the 406 either or am I willing to retard the timing and run it richer in an attempt to deter detonation! That would result in a large loss of power and that is 100% contrary to what I built it for. Like I said, there were plentiful stations with 93 octane when I built the engine. They are no longer. There were also several stations close to me that sold street legal 100 octane unleaded. They are no more! E85 is my best shot.

Every person I have talked to was nervous about all the problems they were going to have to deal with running E85. Almost everyone of them said the problems never arose after they made the switch.

I have friends in Brazil. They have had ethanol for almost 40 years. All of their gas has 25% in it. They also have E100 (100% ethanol). My friends are Harley riders, racers, mechanics and tuners. One of them has my old 80 Vette down there. They think nothing of running ethanol, it is the norm. Brazil uses sugar cane for the most part and not corn. Their production is much more efficient than here in the USA and ethanol represents 50% of the fuel use there.

I am not a greeny by any means, and I don't support subsidies to an inefficient technology, but it is here to stay and used properly is a gift to hot rodders! Order up those 13 to 1 pistons or bolt a turbo or blower to a 10 to 1 compression motor and have fun without paying $10 to $15 dollars a gallon for race fuel!

 

E85 typically has a octane rating of 94-96 AKI. Is that enough for your 12:1 compression?

 

While in the process of landing on specs for my 427 redux I've considered E85. Given a few of the issues such as those brought up here, plus the fact I still don't know where to buy E85 in my locale, I then decided to just stick with a mid-10:1 build for < 92 octane. Besides, that will make more torques than my traction limits can transmit to the ground at WOT anyway.

 

E85 is typically around 106 octane (R+M/2) and behaves as if it is higher because it's latent heat of evaporation super cools the intake track. The cooler your inlet temps, the more resistance to detonation. Approximately every 9 degree drop in intake charge temp is equal to adding 1 full point of octane. It is not unusual to see condensation or even frost on the intake of an alcohol engine. 12 to 1 is still a relatively low compression ratio for E85.

 

You can't swing a stick without hitting an E85 pump here!

 

It's interesting the only E85 station within 20 miles of ne closed last year.
Also, no octane ratings on the pump.
But the boosted LSx guys love it. I think the 100+ octane rating is about right based on their feedback. The OP probably will have success with it and his CR.
Betting Holley can direct him to carb mods.

 

If I had E85 in my area I would do the swap. Fuel system needs to flow 30% more so bigger fuel pump lines may be needed. Also bigger injectors if fuel injected.
I looked into this swap extensively, my biggest concern was corrosion but if you talk to anyone experienced using E85 they will tell you its a myth.

 

You may want to look into this a little deeper. This paper is fairly heavy reading but will correct some of the misconceptions of octane vs. E85

http://www.ethanolrfa.org/page/-/rfa...pdatedLogo.pdf

Of importance:

There is no requirement to post octane on an E85 dispenser.
If a retailer chooses to post octane, they should be aware that
the often cited 105 octane is incorrect. This number was
derived by using ethanol’s blending octane value in gasoline.
This is not the proper way to calculate the octane of E85.
Ethanol’s true octane value should be used to calculate E85’s
octane value. This results in an octane range of 94-96 (R+M)/
2. These calculations have been confirmed by actual octane
engine tests.

 

Thanks Mike, I will read it when I get a little time. The thing about E85 is I have been talking to people who actually use it. Some of the racers who were running fuels like VP16 have switched and they have no detonation problems even with 14.5 to 1 compression. It has to be setup correctly of course, but those that have done it correctly have said they matched or picked up their performance and saved them hundreds of dollars in fuel for the season. A lot of street boosted guys are running it too without the issues people generally say it has. I look at it this way. Most of the warnings of doom come from people who don't run E85. People who are running it love the stuff and say most of the issues never came to be. I choose to listen to those who have experience with it and had positive experiences with it.

A friend of mine got some sponsorship from an ethanol production group so we were using E98 ethanol at Bonneville and El Mirage to cut nitromethane. As far as we could tell, the performance was unchanged. That has very little to do with what I am trying to do, but it gets used in some pretty high test racers these days.

I read a long while back a college was doing testing with E85 and they concluded the best efficiency in power and mileage with E85 was at a compression ratio of 12.5. This was for on road use. I will have to scour the internet for that study. It was a long time ago and I can't remember which college did it.