E85?

'88 XJ, Renix 4.0L (cat-less, CAI, 2.5" cat-back), ~ 175K miles.

We have E85 (85% ethanol/15% gasoline) on the pumps were I live (Oslo, Norway) at a very affordable price.

I figured I could try to run 50/50 E85 and low-grade gasoline. 93 and 95 octane are my choices, this it would equate to 89ish in terms of US octane rating #'s. During winter months the ethanol concentration is closer to 75 percent, so that would make the total octane number, like what, 100?

How does the 4.0 cope with ethanol? What kind of mixtures are safe to run? Do anyone actually have experience with it?

In case of oversized concentrations of ethanol, I assume the knock sensor is able to retard the ignition enough to avoid engine knock? Also, I don't think the rubber hoses going from the tank to the fuel lines, and the injector O-rings are going to suffer from this short-term? I assume the clean(er) combustion would help with "cleaning up" carbon build-up in combustion chambers and valves?

I'm probably gonna see a slight mileage and power loss along with lessened cold starting abilities, but the cost savings might make it worthwhile.

Impressive feedback?

I understand that ethanol is less dense, has less energy, and burns hotter than gasoline. Therefore, more fuel is needed in the combustion and the engine is supposed to run richer.

First of all, how big of an adaption can the Renix ECU make as far as fuel delivery goes?

What would be the best way to go about this for a "permanent" mod? Adjustable FPR? Bigger injectors? Adjustable MAP sensor?

I thought I'd give a tank of 50/50 a try and see how it works. I mean, what is the worst thing that could happen?

The biggest concern is that the fuel lines are not suitable for E85.

RCP Phx said:

The biggest concern is that the fuel lines are not suitable for E85.

Click to expand...

http://www.change2e85.com/servlet/Page?template=Myths
#4,5,6,7

Just Don't Do It.

Ok, here's what I understand about low buck, E-85 conversions.
First, your better off with a carburetor, since they can be rejetted to dump fuel like crazy. Running rich is good, keeps your pistons from getting destroyed from preignition and lean burning.

The stock rubber fuel lines were made to handle gasohols up to E10, as were the o-rings
With E-85 conversion you should change change out all of the aged o-rings, rubber fuel line segments, the in-tank submerged hose and the fuel pump itself. Standard SAE J30R9 fuel injection hose can handle biodiesel and E-85

the stock fuel tank will corrode much faster with E-85 (due to water absorption), and any sediment glued to bottom of the old gasoline fuel tank will loosen and get into the fuel. Bye-Bye injectors.

The stock injectors and fuel map won't meter enough fuel for all throttle positions, so running lean and melting pistons is real a risk. An engine computer needs specific programming to squirt E-85.

And the stock pistons themselves may not last, forged aluminum pistons will hold up better than cast when burning alcohol.

Its possible larger injectors, and a MAP adjuster could get stock ECM to work on E-85, but I bet it would get really poor fuel mileage.
But the rubber parts and tank must be swapped out for new, E-85 rated parts. Otherwise it would be a countdown to big trouble!

And I'd have to check my notes, but I think the stoichiometric mass ratio for ethanol is different enough from gasoline that even RENIX may not be able to handle it (ethanol - I think! - runs a stoich mass ratio of somewhere around 7-8:1, with gasoline running 14.7:1 air:fuel)

Assuming your fuel filters, and fuel tank and clean and free of gunk inside, you can get by with an ecu change and possibly larger injectors (not sure how well the stock injectors flow @ 80% duty cycle).

Methanol is the corrosive one. Ethanol isn't very corrosive. Rubber lines will be fine provided they're in good condition.

You don't need forged pistons to run a fuel that burns colder, and has less stored energy.

Essentially you just need to find a way to squirt more fuel into the cylinders. Advancing the timing some wouldn't hurt either.

E-85 is plentiful here, but it is not worth it. The lower price is offset by the lower gas mileage. Since you are at sea level, if you can find a high altitude CPS for your Renix system, the E-85 might work better than at my altitude. Even 10% ethanol causes a reduction in mileage here, even with the advanced timing from the high altitude CPS.

It will work though.

Fred

http://www.modularfords.com/forums/showthread.php?t=100017

Internal engine E85 corrosion damage. Looks bad, but turns out to be deposits

Yeah, that is my main concern. Ethanol's solvent properties dissolving a lot of sediment buildup and bringing it forth in the system. But that's what fuel filters are for, right?

I think a large gasoline content (50%+) will counter a lot of the other concerns that are brought up.

The gunk seen in that Ford V8 strikes me as odd, I thought the ethanol would burn a lot cleaner? In any case, my motor is probably ten times worse. I dug out a lot of crap from the "valve cover pockets".

I know for a fact that my tank is far from clean inside (swapped in one from the JY).

I have a new fuel filter laying around. Should I leave the old one on for the ethanol attempt?

http://www.jeepstrokers.com/forum/viewtopic.php?f=24&t=453

Have you already seen the damage to this stroker from lean burning E85?
Overheated and "tulipped" the intake valves, that was most unexpected.

I wonder what ratio of ethanol/gasoline will run cool enough.


that DOHC 4.6 Ford was a gasoline burner before going to E85.
A vehicle run it's whole life on ethanol does well

Assuming:

High compression stroker + pure E85 + stock injectors = not a good idea?