octane boosters

womanator said:

I'm a big fan of aluminum heads.
Blend the chambers-no sharp edges.
Have the exhaust flow for the cam you are running.
If you can't get then exhaust out you keep the heat in the engine.

My True street car.
67 Dart.
440 ci.
11.5-1 engine.
Eddy heads
Stock flow on my bench.
in.-246 @.600
ex.-198@600
Cleaned up.
[email protected]
[email protected]
Piston .004 above the deck.
Cam-Hughs grind #htl6064bs .587 in .594 ex.
Installed @103.
tti's 2" headers with 3" ex to dump's before the axels.
Timing set @ 34 degree's total in by 2800 rpm's.

280 Pass's before taking the bottom end apart.
No broken rings or pistons.

After 100 pass's down the strip took the heads apart and the valves were gum'd up=carbon.
This was with Chevron 92 octane with techron.
Changed to Arco= cheap 92 octane and valves were clean when the heads were cleaned up this year.
Don't buy into the cr-p about Chevron gas keeping your engine clean.

I have about 5000 street miles on this engine and 280 pass's at the strip.
The car has run in the 10.70 range at the strip.
I guess I posted this more for the guys wanting to build a high comp. street engine.
For you guy already into detonation the answer is to solve the problem by changing you combo.
I know these are harsh words,
I'm ready for the remarks I'm going to get.
A quick fix is not the right fix,
I have a wall of shame for my mistakes.
Always buy the part for the build you are working on today.
Not for your next build.

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that is one fine ride you have there.i love test and tune with #'s to prove it,nice work."build for what you have,not what you want" are words to live by.

68 Hemis right about toluene, the test mentioned that it works pretty good for a boost. they also did tests on home brew booster. I would say after everybodys input that my app doesnt need booster, it never pings or runs hot. I was under the impression that it would create more power make the car go a little faster, I was suckered by the ad spin doctors

Aluminum heads definitely allow you to run more compression than cast iron heads because of better heat transfer (they cool off quicker/don't hold heat as much). Removing all sharp edges in the combustion chamber helps too. Knock/ping is also known as "pre-ignition" which is simply the fuel/air mixture in your cylinder igniting before the spark plugs "sparks". Sharp edges, heat in the combustion chamber & high cylinder pressure (high compression ratio, nitrous, boost, short overlap camshafts, etc) all increase the problem & slow burning fuels (higher octane rating) help reduce the problem.

Womanator's engine probably lives with 11.5:1 because of the aluminum heads, a lot of overlap in the camshaft, high octane pump gas & not too much extended driving on the street..... just a guess.

Here's some "home brew" octane booster formulas I found online. Xylene & Toluene are near the top of the list & the writter implies that these are the main (if not only) ingredients in octane booster. You can find both at many hardware stores.


Richard Lassiter's "How to Mix Your Own Brew"
FORMULA 1
Toulene
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 Toulene. 12-16 ounces will only raise octane 2-3 *points*, I.e. from 92 to 92.3. Usually mixed with Toulene and advertised as *race formula*.

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 toulene 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", combines 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.


MAKE YOUR OWN OCTANE BOOST
How to make your own octane booster (this is the basic formula of one of the popular octane booster products). To make eight 16 ounce bottles (128 oz = 1 gal):

100 oz of toulene for octane boost
25 oz of mineral spirits (cleaning agent)
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.


Disclaimer: this intellectual property is offered to GN/TType owners at no charge. Use it at your own risk. The GN/TType Organization is is not responsible for any damage or problems associated with use of this information. This information is for use by GN/TType owners on their own personal vehicles and may not be used for profit.

Can anyone validate these home brew mixtures?? They sure beat the little bump you get for $10 a tank using the commercial stuff.

I run an RB on the street with 11.3:1 CR, CNC ported Indy 440-1 heads, aluminum intake,(water pump, timing cover and just about anything else I could buy that was aluminum...) My cam has duration numbers of 278/286 @ 0.05”; 106 lobe separation and .636/.636" lift. I also have large 2.25" headers and 4:56 gears. I run 93 octane street fuel and don't "hear" any signs of detonation - but it is also a pretty loud set up so I'm not sure I would hear anything if it was occurring.
My point is that while I think I am safe using the 93 octane with this set up I know I am on the edge and if I were to be running the car hard I would blend some racing fuel to get my octane numbers up in the 95-96 range. To this end I periodicly dump some of the octane booster in the tank - just for a safety net, but the stuff is expensive. If these home brew blends work as outlined above with no "ill effects" I may start using some toluene instead...

I was told by a guy at Mancini's stand last summer at Carlisle that adding the Octane booster will help stop the cheap pump fuel from boiling in hot humid weather. My buddy and I both had it happen using the 92 pump that they put more ethanal in last year. In fact on Carlisle weekend in July it hit about 103 and was super humid on top of it. And the pump gas fuel when sitting in traffic as we were with his 65 Coronet starting booiling the fuel and flooding. He did not know what was happening and I told him keep the pedal on the floor to start it and then keep it about 2500 when it starts until we move or it would do it again when sitting still. It would cause the car to flood as it pushed the fuel out of the bowls and it was not a needle and seat problem as the same happened to my 63 a week earlier. I even changed my needles and seats thinking they were a problem. Once the car gets moving and gets air going under the hood it stopped until you would get stuck sitting still in traffic for more then a few minutes. It only happens on super hot humid days. So I was going to try some this summer and see if it happens any this year. I am curious if a bottle or two of it will help with the fuel boiling ? Ron

383man said:

I was told by a guy at Mancini's stand last summer at Carlisle that adding the Octane booster will help stop the cheap pump fuel from boiling in hot humid weather. My buddy and I both had it happen using the 92 pump that they put more ethanal in last year. In fact on Carlisle weekend in July it hit about 103 and was super humid on top of it. And the pump gas fuel when sitting in traffic as we were with his 65 Coronet starting boiling the fuel and flooding. He did not know what was happening and I told him keep the pedal on the floor to start it and then keep it about 2500 when it starts until we move or it would do it again when sitting still. It would cause the car to flood as it pushed the fuel out of the bowls and it was not a needle and seat problem as the same happened to my 63 a week earlier. I even changed my needles and seats thinking they were a problem. Once the car gets moving and gets air going under the hood it stopped until you would get stuck sitting still in traffic for more then a few minutes. It only happens on super hot humid days. So I was going to try some this summer and see if it happens any this year. I am curious if a bottle or two of it will help with the fuel boiling ? Ron

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Seems logical, "if it can actually raise the boiling point of the gasoline", at a minimum, kind of like anti freeze raises the boiling point of water by some 40 degrees... Maybe a real petroleum chemist/specialist could chime in... I tried my 80 y/o Uncle Ron, he was an Engineer @ Chevron/Standard for 45 years, but he wasn't ever involved in that end of the company at all, he played with plant design & computers... I just got off the phone with him... My Grandad E.J."Whitey" was a Chemical/Plant & Field Engineer for Shell Oil in some form or fashion for 44 years, unforunately my Unlce or me, we never had those kind of talks, before he passed on... I wish I/we would have now... I always use ERC Racing fuels, just blend a gallon or 2 of the 116 with a tank of 91 octane had great results, but not really needed now with the much better aluminum cylinder heads {or no heat riser to the intake/carburetor} & much better camshafts, much better carburetors, or use a by-pass fuel regulator always, with a adequate return line back to the fuel tank, to keep the fuel pump cool & the fuel recirculating constantly cool too, carburetor heat isulators, plates or phenolic spacers, not being able to even let the fuel have a chance to boil, also insulated fuel lines, always in the engine compartment, all running on 91 octane pump gasoline... I haven't had any of those vapor lock or carburetor fuel boiling issues, for over 20+ years now, even on 100 degree days so far {cross my fingers & toes}... I know it's very common with the Edelbrock & Carter carbs too... I'm a staunch advocate of a Holley style carburetors instead... But opinions will vary vastly too, I'm sure...

383man said:

I was told by a guy at Mancini's stand last summer at Carlisle that adding the Octane booster will help stop the cheap pump fuel from boiling in hot humid weather. My buddy and I both had it happen using the 92 pump that they put more ethanal in last year. In fact on Carlisle weekend in July it hit about 103 and was super humid on top of it. And the pump gas fuel when sitting in traffic as we were with his 65 Coronet starting booiling the fuel and flooding. He did not know what was happening and I told him keep the pedal on the floor to start it and then keep it about 2500 when it starts until we move or it would do it again when sitting still. It would cause the car to flood as it pushed the fuel out of the bowls and it was not a needle and seat problem as the same happened to my 63 a week earlier. I even changed my needles and seats thinking they were a problem. Once the car gets moving and gets air going under the hood it stopped until you would get stuck sitting still in traffic for more then a few minutes. It only happens on super hot humid days. So I was going to try some this summer and see if it happens any this year. I am curious if a bottle or two of it will help with the fuel boiling ? Ron

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Uhhh.... I'm a chemist....doesn't make my car any faster, but whatever. Anyway, adding octane booster will not stop your fuel from boiling. It's not like anti-freeze though that's a good guess. In mixtures of liquids (like gasoline for example) the liquid in the mixture with the lowest boiling point will boil off first, then the second lowest boiling point liquid and so on. The key to "anti-vapor-lock" fuel would be if you could remove all of the chemicals in the gasoline blend with low boiling points or remove the "low boiling fraction" as the petroleum guys would say.

Your cars were experiencing good old (bad old) vapor lock. When the car got moving an the temperature of the carburetors & fuel lines dropped a few degrees the "low boilers" in the gasoline stopped boiling. Carb spacers & "cool cans" do wonders for this problem.

I wish I had some idea of which gasolines had these "low boilers" and which did not since my car gets vapor lock sometimes too. Here's a few chemicals found in gasoline and their boiling points (at one atmosphere of pressure)

benzene 176F
cyclohexane 177F
n-decane 343F
n-heptane 209F
n-hexane 156F
n-nonane 302F
n-octane 258F
n-pentane 96F
toluene 232F
xylene(s) 280F-282F

ethanol 173F


Looking at the list, it seems like n-pentane is a likely problem for vapor lock. I wonder which gasolines have the least amount of pentane?

PurpleBeeper said:

Uhhh.... I'm a chemist....Your cars were experiencing good old (bad old) vapor lock. When the car got moving an the temperature of the carburetors & fuel lines dropped a few degrees the "low boilers" in the gasoline stopped boiling. Carb spacers & "cool cans" do wonders for this problem.

I wish I had some idea of which gasolines had these "low boilers" and which did not since my car gets vapor lock sometimes too. Here's a few chemicals found in gasoline and their boiling points (at one atmosphere of pressure)

benzene 176F
cyclohexane 177F
n-decane 343F
n-heptane 209F
n-hexane 156F
n-nonane 302F
n-octane 258F
n-pentane 96F
toluene 232F
xylene(s) 280F-282F

ethanol 173F


Looking at the list, it seems like n-pentane is a likely problem for vapor lock. I wonder which gasolines have the least amount of pentane?

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Interesting 6 of them have a lower boiling point than water has of 212*F... thanks for a clarification

No it was not vapor lock as I have seen that many times over the years. My buddies stock 68 Cuda Formula-S 383 car would do it sometimes on super hot summer days. He still had the 383 exh manifolds on it and the stock fuel pump and it would just die while driving along and not start back up. The carb bowl would be empty. Our cars (his and mine) still had fuel in the bowls as I could actually see it boiling. And I could restart them by holding the gas pedal on the floor just like starting a flooded car as it was pushing the fuel out the bowl vents and venturi's. I already had a phenolic spacer under the carb so I added a heat shield under the spacer also as you can see here. It never did it again as it was still hot and humid but not as bad as it did not go over 100 degrees anymore. I also added the good old cool can but have not used it. I figure if its a bad enough day that I may worry it could happen I can slap and ice pack in the cool can and carry an extra ice pack in my little cooler with the cold drinks ! Ron

PurpleBeeper,
That's why I posted the cam # so interested people could look it up.

I have no issues running AV gas..... Around here it's 100 low lead...... I dont use it to allow more timing advance..... I use it because it slows the burn resulting in a prolonged expansion of gasses giving more usable energy.... Also because I have high compression, and want to avoid the multiple flame fronts from rattling my pistons "pre-ignition".....

@67 B Body the low lead av gas has a lower level of lead than the other av fuel mixtures but its relevant to the other av gas 's level. it's still loaded with lead compared to atomotive gas.

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My car sat for a very long time, the gas was very stale an it ran pretty bad so based on the swag method ( I'm sure Purple Beeper would be proud) I added pure acetone to the tank about two glug glugs, and shook well. the car ran like a champ, I changed the filter, plugs and wires afterwards to start with a clean slate. The acetone's supposed to break the surface film of the gas and make it vaporize atomize more efficiently, and I think, but I'm not sure, it keeps all the additives in gas in suspension and stable

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Damn Stumper your engines a beast 278/286 @50?

Big Sugar said:

Almost all available Octain boosters sold at automotive stores are bottles of Mental Horsepower, that have only a slight effect on your pump gas Octain Level......Basically it's like a clean car feels faster.


Ron

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Thats what I was always told. Unless you are running high compression and need the octane you arent making anymore power per say as actualt just running without pre-ignition issues. Now I suppose you can run more timing and it should be a little quicker I would think but unless the engine was built to use it ... its not making a big difference

Ive never heard good things about octane boosters. I mix 5 gallons of 110 with my 93 to get to 98 octane. It allowed me to advance my timing with no more pinging. 440 0.030 over , 11:1 comp., .542 lift cam.