fuel system question

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PEZi
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fuel system question

Postby PEZi » Thu Jan 01, 2009 7:15 pm

i currently have my truck set to run 93 octane... and it runs fantastic so i don't want to drop back down to 91.

the problem: in colorado we can only get 91 so i've been blending a custom race gas with the 91 to make it roughly 93... but this stuff is too expensive. i was thinking of switching the custom blend to E85 which is 105 octane... my current blend is 107 octane but the E85 is significantly cheaper. the densities and octane are close so i wouldn't have to change anything with the engine in that respect.

other details: i will only need a half gallon of E85 per every 5 gal of 91

the question: will running E85 through the fuel lines, fuel pump and most importantly carb hurt the system with the quantity i need? i've heard that the ethanol will eat away certain parts over time when running 100% E85 but i wonder if the smaller amount i'm using will cause major problems or not. i know that most gas station pumps currently have 10% ethanol and there are no symptoms of part failure from that yet and there has been 10% ethanol at the pumps here as long as i can remember.

please discuss


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breadbox
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Re: fuel system question (PEZi303)

Postby breadbox » Sat Jan 03, 2009 5:04 am

Correct me if I am wrong.

Octane ratings have to do with compression. Like the higher the compression the higher your minimum octane rating to run the motor. Or why are there different octanes?

You could call a chevy tech and ask what they use for the fuel lines in the e85 vehicles if you think your lines with get eaten up.

Its pretty sweet that you mix your own fuel.

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PEZi
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Re: fuel system question (breadbox)

Postby PEZi » Sat Jan 03, 2009 2:09 pm

yeah... compression and timing...

i currently get too much pinging on 91 and the truck seems sluggish in mid range... the blended fuel gets rid of both issues

i know that to run full ethanol you need new lines, a pump and certain parts within the carb... i just figure that since pump gas already has ethanol in it and i'm not adding too much more to it that it should be ok... but i'm not sure

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Re: fuel system question (PEZi303)

Postby breadbox » Sun Jan 04, 2009 5:58 am

I googled and found this, not sure if you caught this.

"Ethanol And Effects On The Fuel System

Q. Hi Vincent, I really liked your writing on ethanol, you really know your stuff. I've learned a lot. This is the best introductory write-up I've come across. I am looking into getting a Fiat 126BIS, and running it on ethanol. I hear that ethanol can rot rubber components in engines; gaskets etc. since they are derived from crude oil. Ethanol And Effects On The Fuel System

Some refer to it as a sort of "drying out" process. Is this so? Also, does ethanol damage catalysts?

Yours faithfully,John

A. A 10% blend of ethanol and gasoline will not harm any engine or fuel system component. However, the ethanol has a cleaning effect that will remove rust and other junk from the fuel system. This necessitates frequent fuel filter changes until the fuel system is cleaned out.

No modifications need to be done to allow an engine to run on a 10% blend of ethanol and gasoline. There is, in some areas, an 85% blend of ethanol and gasoline that does require engine modifications.

Actually there is no rubber used in the fuel system. All the fuel lines are made of Neoprene which is impervious to degradation by gasoline or other additives."

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PEZi
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Re: fuel system question (breadbox)

Postby PEZi » Sun Jan 04, 2009 3:30 pm

interesting.... looks like i have an answer

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Re: fuel system question (PEZi303)

Postby 2kredz3 » Fri Feb 20, 2009 7:28 pm

i know the fuel lines in my truck are rubber, but they are rated for the delivery of fuel. there are also some small parts in the carb that were rubber, but i dont believe that they are submerged in gas in that section of the carb. it has been almost a year since i rebuilt mine, of course you are probably not running the stock carb anymore anyway.

i would caution you tho, E85 does not have the same properties as race fuel so you may have to play with the mix some. an example of this was my 03' dodge ram hemi, i had to actually run a tune for 89 to run the 93 from race track when the 10% blend first came out here. if i wanted to run my 93 tune i would have to get 5 gal of 115 (air plane fuel @ $12 per gallon) to mix with 30gal of 93 with 10% e85 it was ridiculous. about a year after i started that mess a new tune was written for the truck and the problem was solved (fuel injection is easy like that) let me know how it works out, would be nice to run my truck on e85 all the time.


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