12a with Nikki carb running premix + e85?
 

Ok I searched and read a few posts but they all sounded like they wanted to run e85 exclusively. However I've had acouple of guys come into my work and mention that they are running 1/3 e85 2/3 gas and were very enthusiastic about it. They said it burns cleaner, gives their car a lil more get up and it's usually a lil cheaper than gas. Also one of the guys I work with said that because of the higher octane rating you can run more advanced timing. Is any of this true? And does anyone run an e85 mix in their Nikki carb'd 12a? And would there be any issues with mixing marine 2 cycle with it?

I've heard that E85 eats through certain types of rubber fuel lines. Depends on what type of rubber base it is. Based on how it really seems to make no difference if we run premium or not I would say its probably not going to give you any real perks. It also kills your mileage a bit too

and i've heard that it takes more of the e85 to get the same power so even tho it's cheaper ur really not saving anything.

Not worth the time Joe. The issue you'll have with the 1/3 + 2/3 idea is that you will never be filling up with the exact same amount of fuel, so your tune will always be a little bit off. Just stick with good old 87 octane and be done with it.

I agree with all the responses. It will kill your gas mileage. You MUST jet up your carb to run it. Fuel pump, fuel lines, etc. would have to be upgraded. Then the time you are traveling and can't find E85, and you run 87 octane....you will be pig rich and it will be doggy.

Not to mention, government FINALLY has realized this ethanol for fuel is a farce and is pulling all subsidaries for it's production. Soon you will see e85 prices going up.

NOW, there is an exception!!! If you are supercharged or turbocharged.... then this is the wonder fuel for you!!

I am considering changing my 2010 Subaru WRX over to a tune running E85. The power production is incredible when running E85 in a "boosted" situation.

You really need to stop listening to the piston-heads =P

Turbo rotaries seem to really like this stuff however...

on a turbo engine the alcohol, helps in 2 ways. the first is just that its high octane, the second is that the alcohol removes a lot of heat from the engine.

on an NA you don't need the octane. the cooling helps a little, but not much.

and the bad part, is that its got less energy density, so you need 40% more of E85 vs gasoline

I have also been told by a forum member here that runs E-85 that it takes a special type of premix. Apparently 'regular' premix doesnt mix correctly in the higher alcohol leveled fuels. Cant remember the name or type of premix he said to use (didnt really need to remember sonce I dont run it).

Alcohol belongs in my martini shaker, not in my RX-7.

Lower power density, both per liter volume and per kilogram mass.
Lower peak specific impulse.
Corrosive exhaust mixture for most anything other than stainless steel.
Hydrophilic and subject to phase separation under long storage.
Solvent to several types of elastomers still in use in 1980.

https://upload.wikimedia.org/wikiped...gy_density.svg


If I could buy street fuel with 0% ethanol, I would. Gleefully.

It's a great fuel for engines designed for it, which NA 1st-gen rotaries are not.

What everyone forgets about the energy density thing is that ethanol has a MUCH richer stoich point than gasoline. Yeah, you have to burn a large amount of fuel, but the energy output at stoich is higher than gasoline, even without the octane and cooling benefits. (Fun fact: for E10 gasoline, the stoich point is no longer 14.7:1. It's closer to 14.1:1. Widebands still read the same, since they go off of lambda readings, not actual mass flow rates.)

This is the same reason that hydrogen as an ICE fuel sucks despite its huge energy density: stoich for hydrogen is like 34:1! Given that ICEs are generally airflow-limited, burning hydrogen in them thus makes very little sense. The hydrogen-fuelled RX-8 only made 120 HP.

That said, I probably wouldn't bother with E85 for an NA car. The tradeoffs aren't worth the benefits with such a low compression ratio. Besides, E85 would probably confuse the crap out of the stock Nikki, and you'd have to do some mods to make it drive well. Though I've never tried it myself. Plus, there are some issues with premixing and E85, I understand.

All good points there guys..... most everybody is spot on. I actually dyno -tune cars for a living so I'm very familiar with E85 and what it takes to run it safely and properly on a vehicle. It does take roughly 30-40% more fuel to make the same power on E85, so the first thing you have to address is your fuel pump. You need to be able to supply enough fuel flow and still keep duty cycle levels in the safe range, below 85%. This can sometimes be tough to do on a single fuel pump.

I do a lot of big boost Mustangs that run E85... some turbos, some PD blowers, just did a compound induction GT500 with twin 50mm turbos pumping into a Whipple 3.4L blower. Made 893 hp on 93 octane pump gas, and 1181 hp on E85. This car had a triple fuel pump set up with 0 awg wire feeding the fuel pump driver module and a Kenny Belle Boost-a -Pump that cranks pump voltage up to 17-18 volts. -8 lines from the tank to the rails and high flow billet rails feeding 160 lb/hr injectors. This crazy fuel system was just barely enough to feed that beast. So, it's usually a pretty involved process to switch to E85.

It is a great fuel, comparable to C16 race gas... it just doesn't cost $13.50 a gallon. But it's still has it's limitations. It will still detonate, but is usually less catastrophic than gasoline since it has a lower BTU content.

Once I get my turbo build running and broken in I'll probably be setting up the jetting for running E85 at some point. Unfortunately, the only station that carries it near me is about 10 miles away. Being carbed makes it a simple swap of the jets if I need to switch back and forth between pump gas and E85. BTW I'm using an OER for this. I wouldn't dream of trying E85 on a carb like the Nikki that offers very little in terms of jet selection. The carb will need to be "jetted up" on all circuits. Idle, transition, and main.... and you just don't have that tunability in a stock nikki.

Soooooooo, long story short Joe, save the corn fuel for the boosted guys and stick with 87 while you're NA.

^^... & enjoy not having to fill your tank every 120 miles.

any updates on folks who have actually used e85 on a carbed engine?

no "i heard" bs..

I heard if you saw your right foot off with a jagged piece of glass, it will hurt a lot.
Published literature based on previous research agreed.
Sound theory based on well-understood physics also made it clear that it would negatively impact my driving ability.
So I decided to skip experimenting with it myself.

i heard the 787B makes more power on pump gas vs race gas. they also published the fuel and mileage from the actual race and its approx 12mpg.

Basic E85 facts.

stoch for gas `14.7:1 stoch for e85 about 9:1 (depends on mix, it changes based on temp in the region, most you will see is 75-80% ethanol)

power mix for gas 11-12.5:1 (depends on setup), power for e85 5-7:1

BTU per gallon is higher for gas than e85 (how much power is possible for any given amount of fuel), and Im not sure what this number is off the top of my head, but e85 makes about %20 less power per gallon.

that being said under power, youve got 30-40% MORE FUEL in the combustion chamber. So for any given NA engine, you will make 5-10% more power running e85.

Now if you got a turbo, or a high compression engine designed for Alchohol then the difference can be substancially higher.

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Yes, e85 is corrosive (as is any alcohol, especially methanol) but not as bad as you think. Any car built since about 95-2000 has a fuel system that should have no problem. Before that, rubber and certain plastic parts need to be changed.

In a first gen with a carb, my guess is you would need to replace pretty much every fuel item in the car, and rebuild the carb with high quality parts and rejet.
This includes the fuel tank, as its coating on the inside is not compatable, and the e85 is going to clean the shit out of it and clog up everything else.


unless you got a turbo, i doubt its worth it, and e85 is difficult to tune for in carbs, and causes cold start issues below 50deg.


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Normal premixs DO NOT WORK with ethanol. THe only 2-cycle ethanol oils are made from Castor oil (as in castor beans, which is also used to make poisons, such as Ricin, and are restricted) the stuff is expensive and you have to use about twice as much as regular premix.