Things to make 4.0 alchol efficient

[sun417]

I know higher compression is one. In rebuilt plan to have some taken off the heads. what else will help make this thing a real alchol burner. I read that if mods are made mpg will be same or better on alchol even though slower burn than gas. Advance timeing would help I think. Give me some ideas of what needs to happen to make the engine efficient, I don't want to go to high on the compression in case I have to burn gas in it. Applying for permit to make ethanol getting ready to built my still.

 

[AllanD]

The quickest way to build for compression in a 4.0OHV is either swap
a 93-94 shortblock under your later heads.

there are MAJOR differences in the way the bottom ends are designed
between when the earlier pistons were used, and your 1997 which uses the later
"lightweight rotating assembly" which has lighter crank counterweights to match the lighter pistons used.

Frankly I'd get a '93-94 short block and put late heads on it.
but remember after you do that you'll have some issues running
regular gasoline.

I have a set of late heads set aside for my own building an alcohol engine...
as soon as commercial butanol becomes available.

as for HOW efficient? on ethanol you are rather limited as there is only about 65% as much heat energy in the fuel.

with Methanol there is about half the heat energy
but methanol doesn't need as much air to burns so you can cram three times as much of it into the engine and you get a 50% power increase.

Butanol has 92% as much energy as gasoline and burns best with increased compression >12.5:1 so you get some of the power
back, greater compression offers greater efficiency.

 

[reno]

So my 93 should be Butanol ready now?

 

[AllanD]

There is one other think about butanol.

It's got a high boiling point and a really LOW vapor pressure
(about this you should be thankful, butanol smells like puke or Rancid butter)

So suddenly introducing Butanol into a RUNNING engine presents no issues
but starting a COLD engine on pure butanol can be difficult.

So Butanol will need either 10% Gasoline or Acetone mixed into it
as a starting aid.
OR
you will need a seperate tank of "startup fuel"

My preference would be one of those solenoid actuated "either/alcohol"
tank (looks like a BernzOmatic propane cylinder screwed onto a solenoid
valve assembly) that are commonly used on medium duty trucks.

Or simply wait for the next generation of ranger with the 3.5liter twin cam
v6 engine which is SUPPOSED to be offered in a GDI/Multi-fuel configuiration.

AD

 

[WhiteBroncoII2WD]

The quickest way to build for compression in a 4.0OHV is either swap
a 93-94 shortblock under your later heads.

there are MAJOR differences in the way the bottom ends are designed
between when the earlier pistons were used, and your 1997 which uses the later
"lightweight rotating assembly" which has lighter crank counterweights to match the lighter pistons used.

Frankly I'd get a '93-94 short block and put late heads on it.
but remember after you do that you'll have some issues running
regular gasoline.

I have a set of late heads set aside for my own building an alcohol engine...
as soon as commercial butanol becomes available.

as for HOW efficient? on ethanol you are rather limited as there is only about 65% as much heat energy in the fuel.

with Methanol there is about half the heat energy
but methanol doesn't need as much air to burns so you can cram three times as much of it into the engine and you get a 50% power increase.

Butanol has 92% as much energy as gasoline and burns best with increased compression >12.5:1 so you get some of the power
back, greater compression offers greater efficiency.

So there are other people herer that see butanol as a future fuel