Home Brew AvGas
Here's some nifty info I came across while
looking for block dimensions for Mopar's. I haven't tried it, so attempt
at your own risk. Don't say I didn't warn you..
As you can deduce from reading commercial
"octane boosters" don't raise your octane significantly per
can (usually 12-16oz.) This info tells how to raise plain ole' hitest
into the realm of Cam 2 and company, usually for prices that will average
out to about a dollar more a gallon.
A little mathmatical note: to figure any
possibly octane number from the additives, take each components octane
and multiply by the number of "parts" it represents, then
divide by the total number of parts. For example:
2 parts Xylene to 7 parts Sunoco ultra
94
2*117=234
7*94=658
234+658/9 = 99.1111
Percentage of Xylene is 2 divided by total
# of parts(9) =22.2222%
See? Wasn't that easy?
Octane Boosters
Formula #1 - Toluene
R+M/2.........114
Cost...........$2.50/gal
Mixtures with 92 Octane Premium
10%...........94.2 Octane
20%...........96.4 Octane
30%...........98.6 Octane
Notes: Common ingredient in Octane Boosters in a can. 12-16 ounces will
only raise octane 2-3 *points*, i.e. from 92 to 92.3. Often costs $3-5
for 12-16 ounces, when it can be purchased for less than $3/gal at chemical
supply houses or paint stores.
Formula #2 - Xylene
R+M/2.........117
Cost...........$2.75/gal
Mixtures with 92 Octane Premium
10%...........94.5 Octane
20%...........97.0 Octane
30%...........99.5 Octane
Notes: Similar to Toluene. 12-16 ounces will only raise octane 2-3 *points*,
i.e. from 92 to 92.3. Usually mixed with Toluene and advertised as *race
formula*. Home Depot sells this as a solvent, but at a rather pricy $10.77
a gallon
Formula #3 - Methyl-tertiary-butyl-ether
(MTBE)
R+M/2.........118
Cost...........$3.50/gal
Mixtures with 92 Octane Premium
10%...........94.6 Octane
20%...........97.2 Octane
30%...........99.8 Octane
Notes: Oxygenate. Very common in octane booster products. Has lower
BTU content than toluene or xylene, but oxygenate effect makes the gasoline
burn better and produce more energy.
Formula #4 - Methanol or Ethanol
R+M/2.........101
Cost...........$0.60 - $1.75/gal
Mixtures with 92 Octane Premium
10%...........94.3 Octane (Methanol)
10%...........94.7 Octane (Ethanol)
20%...........Not Recommended
Notes: Methanol is wood alcohol. Ethanol is grain alcohol and found in
Gasohol in 10% ratios. Both alcohols are mildly corrosive and will eat
gas tank linings, rubber and aluminum if used in excessive ratios. Main
ingredient in "Gas Dryers", combine with water.
Formula #5 - Isopropyl Alcohol and Tertiary
Butyl Alcohol
R+M/2.........101
Cost...........$0.60-$1.50/gal
Mixtures with 92 Octane Premium
10%...........94.5 Octane
20%...........Not Recommended
30%...........Not Recommended
Notes: Similar to Methanol/Ethanol. Isopropyl Alcohol is simply rubbing
alcohol.
Sample Mixture
To make your own octane booster, it is easiest to make up a large batch,
and then bottle it up in "dosage-size" uses.
Below is the basic formula of one of the popular
octane booster products. To make eight 16 ounce bottles (128 oz = 1 gal):
o 100 oz of toluene for octane boost
o 25 oz of mineral spirits (cleaning agent)
o 3 oz of transmission fluid (lubricating agent)
This product is advertised as "octane booster with cleaning agent
*and* lubricating agent!". Diesel fuel or kerosene can be substituted
for mineral spirits and light turbine oil can be substituted for transmission
fluid. Color can be added with petroleum dyes.
