Don Terrill’s Speed-Talk

A number of years ago, I asked a University (Engineer) student, what was in Octane Booster. He did some tests & said the main ingredient was Diesel fuel! Will the right amount( which I don't know) added to, say, 94 at the pumps, boost it up measurably, by slowing the burn rate? I may be way off base, but I'm always ready to learn. About 1975 or so, we used to throw a handful of mothballs in the tank when we went street racing, reasoning that it was basically naptha & should help increase the octane of our fuel. By the seat of the pants feel, we swore it worked. Exhaust sure smelled funny too LOL. Any one out there to tell me that we were nuts, or was there actually something to it. Yea , I know , laugh all you want, but we at least tried , in lean times, to go fast .Thanks guys

toolmakeron wrote:A number of years ago, I asked a University (Engineer) student, what was in Octane Booster. He did some tests & said the main ingredient was Diesel fuel! Will the right amount( which I don't know) added to, say, 94 at the pumps, boost it up measurably, by slowing the burn rate? I may be way off base, but I'm always ready to learn. About 1975 or so, we used to throw a handful of mothballs in the tank when we went street racing, reasoning that it was basically naptha & should help increase the octane of our fuel. By the seat of the pants feel, we swore it worked. Exhaust sure smelled funny too LOL. Any one out there to tell me that we were nuts, or was there actually something to it. Yea , I know , laugh all you want, but we at least tried , in lean times, to go fast .Thanks guys

Octane does not affect the fuel burn rate which is principally determined by chamber turbulence. What it does is allow more time before the onset of autoignition due to increasing pressure and temperature of the end gas. This allows the flame front to consume the end gas before it ignites spontaneously.

The mothball issue is mostly folk lore. It goes back to the day when fuels had octane values in the 70-80 range. Today it would reduce octane value; certainly for any race gas.

Toluene has often been used in Formula One racing. Its purpose was primarily to increase fuel economy since the cars were limited in fuel capacity by a specified tank size. By increasing the density of the fuel, more fuel mass was available, more miles per gallon and, hopefully the avoidance of a pit stop. Fuel consumption stategies were (and in some cases still are) an important part of race stategy.

The race goeth not to the fleet of foot but to the quick of mind.

Today things are a whole lot different than they used to be.
For race gas in the 80's, we would purchase a 30 gallon drum of "indolene 30" from the local gasoline distributor and mix it in a 55 gallon drum with 10 gallons of Toluene. That amount would last us a little over a month for our 12/1 compression ratio "limited late model" so, we did it about 3 or 4 times a summer.

You probably can't do that kind of thing anymore.

Well, maybe with leaded av gas and toluene ...

I wonder if the mothballs myth started because someone was seen dropping GI C-ration trioxane heating pellets into his gas tank? Some were about the diameter of a quarter and a half-inch thick. They are white crystalline looking tablets like a big aspirin. They dissolve in gasoline and oxygenate it. Several years ago there was a rash of fuel cheating in some circles (who shall remain nameless) with dioxane and trioxane until the corner workers complained about the exhaust fumes.

http://en.wikipedia.org/wiki/1,3,5-Trioxane

I think years ago mothballs contained naptha.

If you want homebrew, Xylene from the hardware store + a good dose of Lucas lube/cleaner.

I got this from the web back in 2005. It is pretty self-explanatory.

MrWOT wrote:If you want homebrew, Xylene from the hardware store + a good dose of Lucas lube/cleaner.

Xylene is an excellent octane improver additive. However, it must be either p or m xylene and not o xylene. Most hardware store blends are a mixture of xylenes due to similar distillation points; therefore the actual octane value is unknown.

David Redszus wrote:Xylene is an excellent octane improver additive. However, it must be either p or m xylene and not o xylene. Most hardware store blends are a mixture of xylenes due to similar distillation points; therefore the actual octane value is unknown.

Do you have the octane values for the three? How low is the lowest?

toolmakeron wrote:A number of years ago, I asked a University (Engineer) student, what was in Octane Booster. He did some tests & said the main ingredient was Diesel fuel! Will the right amount( which I don't know) added to, say, 94 at the pumps, boost it up measurably, by slowing the burn rate? I may be way off base, but I'm always ready to learn. About 1975 or so, we used to throw a handful of mothballs in the tank when we went street racing, reasoning that it was basically naptha & should help increase the octane of our fuel. By the seat of the pants feel, we swore it worked. Exhaust sure smelled funny too LOL. Any one out there to tell me that we were nuts, or was there actually something to it. Yea , I know , laugh all you want, but we at least tried , in lean times, to go fast .Thanks guys

That is interesting! I say this because, I have a bunch of old inventory from my in-laws motorcycle shop and there is a bunch of old Cal Products "Rocket Fuel" octane booster additive. Not the liquid tubes, but little packets of powder that look like Lowreys seasoned salt and BBQ rub...It says on the instructions to mix it in a clean container with 12 oz of diesel fuel, fuel oil or kerosine. One ounce treats like 2 gallons.

I am going to mix some of this stuff the next time I Dyno a pump gas engine for fun.

MrWOT wrote:

David Redszus wrote:Xylene is an excellent octane improver additive. However, it must be either p or m xylene and not o xylene. Most hardware store blends are a mixture of xylenes due to similar distillation points; therefore the actual octane value is unknown.

Do you have the octane values for the three? How low is the lowest?

The octane response of aromatic compounds will depend on the amount of lead that is used.

Lead...........0.............2...........4 (g/gal)
oXylene.......100.3........100.0......100.0
mXylene......115.0........119.5......121.5
pXylene.......109.6........117.1......122.0
indolene......107.0........103.5......103.5

David,

Interesting. Does Toluene also react in a similar manner in the presense of lead?

Paul

The octane response of aromatic compounds will depend on the amount of lead that is used.

Lead...........0.............2...........4 (g/gal)
oXylene.......100.3........100.0......100.0
mXylene......115.0........119.5......121.5
pXylene.......109.6........117.1......122.0
indolene......107.0........103.5......103.5
Toluene......109.1.......113.0.....114.0

in the 70's i used 2 washer pumps with 50/50 water/methanol #1 turned on at 8 pi boost.
#2 on at 18 psi boost.
up to 22psi boost.
worked real nice with pump gas.

will this possibly work on a N/A 10.7:1 BBC iron head truck?
not mine, just asking.
i was thinking of a throttle position switch in series with a vacuum switch, as it only pings heavy throttle when the 93 turns out to be 87.
Thanks!

Water works great to slow things down. But using a good pump makes all the difference, water likes 90+psi to atomize nicely. Adding alcohol changes things.