I was wondering if anyone has converted their old hot rod to run on E85 to make more horsepower and use in higher compression motors.  I think I am going to try it with my 62 F100.  It's a built 292 stroker and we are questioning 91 octane fuels ability to handle the compression, I can also make more horsepower with E85.  I am running a TBI fuel injection setup on my engine.  To my knowledge all I have to is increase injector pulse width to richen mxture and I believe I have to advance the timing for the extra fuel.  If any one has tried E85 I would love to here how it went.

Robi

Hi, you should take a look at our Horsepower Calculator and our E85 Calculator Article ...



Basically going from Gasoline to E85 you're going to get about a 15% boost in power from the oxygenation and the different fuel energy density.



You will also need larger injectors (about 40% larger) since typically stock injectors are sized to max out around 70 to 80% duty cycle, you will not have enough head room left on your stock injectors to compensate for an E85 conversion.



As far as how much compression you can run... use or temperature model in the calculator to find your new CR given the higher auto ignition temp of E85 ... and yes some timing advance is required for MBT (mean best torque) but unlike gasoline, you may run into and PASS MBT long before you reach pinging... so the only way to tune E85 for MBT is going to be on a dyno because the knock limit is so high that if you keep advancing timing you reach and pass MBT without any sign of knock (where as gasoline will typically give MBT a few degrees before knock so you advance up to that limit.



Given this is an older motor and you'll be making 15 to 20% more power... I have to ask this... are you using aluminum or cast iron heads ? keep that in your mind (extra cooling).... 20% more power is about 80% more heat ... since engines are typically only 25 to 40% efficiency in converting fuel to power, the rest is used to heat stuff up

I have run my 333 Y block on a dyno back to back with 110 race gas and E-85



12:1 compression, Iron heads single 4 bbl



It made 424 hp with a 750 Holley and race gas. It made 432 with a 750 Holley converted to E-85. Finally it made 435 with an 850 Holley on race gas.



It was very sensitive to timing. anything more or less than 33 degress lost power.



You could definitely detect the evaporative cooling from the ethanol as the manifold was cold after the pull. The wide band oxygen sensor read about the same as for race gas so our air fuel ratio was slightly rich at WOT which is where you want to be. We had a knock sensor installed and had no pre-ignition at all. E-85 is a great option as a cheap fuel for high compression engines. You can do the math to see exactly how many lb/hr you need for your engine, and size up your injectors accordingly

Adandos.  Welcome to the site.  Some great info being passed along here.

Lorena, Texas (South of Waco)