Can you run E85 through carbs? I have a set of 40mm DCOE webers and am looking into what I have to do to the fuel system to run E85 like new fuel lines, pump, filters etc.

Any help or advice is appreciated.
Cheers

I ran e85 through twin 45 weber on the dyno but the gains from just running the e85 without having an engine built to run it effectively were not worth the effort. I replaced my old lines with new modern fuel hose but i would have to check what type, i have been told since then that a majority of modern fuel line will handle e85 internally as the linings suit it but it can eat away at the outside. if you have an in tank pump and require hose that goes inside the tank there is a specific type of hose you will need.

Weber performance have told me that there is only one type of gasket kit for webers and they have not had any reported problems with running e85 or alcohol. Its just a matter of replacing your jets with much larger ones, mine went from 145 main fuel to over 200.

What are you doing to the engine? If your running it through webers i'm guessing no turbo, are you increasing the compression?

The gains on a stock engine are 1) reduce petroleum dependency and 2) reduce emissions. It will use more E85/mile than petrol/mile (hence the much larger jets).

E85 will gain HP if you bump up the compression of the engine via new pistons or a supercharger or turbo.

Hi crumb, thanks for the info mate, interesting to hear that no changes are necessary on the webers. The engine will be running in a 1200 ute so I will need to upgrade the fuel lines from the tank to the pump and pump to carbies.

It will be a rebuild of my A14 using an A15 crank, flat top pistons and shooting for a comp ratio of about 12-13:1 using E85.

I've heard that running high comp with E85 will push more HP but not sure how much of a gain I could expect to get. And as yourself and ddgonzal stated bigger jets and more fuel will be the order of the day.

Would this mean that the standard mechanical fuel pump might struggle to keep up fuel flow? And would an electric upgrade be on the cards

Cheers
Shero.

It is the 13:1 compression that generates more HP. To run it you need higher octane fuel - for example racing petrol or Ethanol or "alcohol" (methanol). Of the three only E85 is street legal and affordable and somewhat available.

The stock fuel pump is good for 120HP or so. About double the stock HP. But you don't want to chance a lean-out, so I would move to a high-volume pump if making more than 100 HP.

Thanks ddgonzal, good to know that the fuel pump will need an upgrade. I'm hoping for more than 120hp out of the combo. Apart from a lean out, what other risks are associated with running such high comp ratio?

High compression doesn't cause lean-outs, but running out of fuel will.

12:1 is nothing - the SCCA racers run 14:1 in their A-series engines. Just like always, make sure the block and head face are perfectly clean when you install the head. Torque to the pattern, in steps, per the factory service manual. Use the '13' head bolts and torque to the 13 specs. Like always, don't let the engine pink/ping even a little bit.

The important thing with E85 is to get the mixture correct, which means rejetting, new air jets, new carburetor pump settings, new power valve. Probably new transition jets too. Running the engine too lean is the easiest way to break something.

Thanks for the advice mate.Very helpful

You're also going to need to look at some alcohol suitable emulsion tubes. For two reasons - 1. the sheer volume of fuel vs petroleum/gasoline based fuel going through the carb is around 30-40% higher (a very rough approximation on my part) 2. the viscosity of alcohol based fuels is somewhat different too so how well they emulsify (aerate/mix with air) is not the same.

It's a significant enough issue that there's a considerable difference in how a webered engine runs on pump fuel vs e10 pump fuel. There's a yahoogroups email list called 'sidedraft_central' that has an enormous amount of info on this and has apparently been a godsend to guys in california (to name one location) where apparently gasoline/petroleum fuel was phased out and e10 was the only std pump fuel available. Obviously we have options here and running e85 is a different ballgame again, but the info on htat list is well worth it if you have the time to go through the archives and the various files/database on its homepage.

I also recall specifically there's been a thread on here where a local (Aus) guy discussed running e85 on either an ipra or maybe 2 litre sports sedans a15 engine. I used to have it saved but am on a new pc and struggling to retrieve much off my old hard drive on the previous pc that died. But i do recall he was even kind enough to list the specific emulsion tubes he ran on it.

As far as compression goes, generally the more the better, if the fuel will tolerate it and e85 certainly will esp with enough cam duration. it also makes a bit of extra power over regular fuel even without the raise in compression ratio due to the extra cooling effect of the alcohol allowing a slightly more denser intake charge to be drawn in there - more air to support the more fuel combustion, a bit like how motors make slightly more power at night with the cooling temps leading to denser air.

In WA we have been running E10 since 1989. No mods are needed, either in fuel lines nor in carb tuning. Only in engines running lean to start with did people notice it.

E85 is a different matter.