Homemade Octane Boost ??

[got snake?]

I"m telling my engine builder to make my motor run on 93 octane. And still produce 450hp. Problem solved. A friends uncle told me to try mixing 83 and 93 octane to get a higher rating. This same person drinks warm beer.

GS

[427 S/O]

use to be when regular gas was the last to have lead, mixing was a good idea. Not any more.

[Steve R]

GS,
believe it or not, that did work when leaded gas was avail. the technique was to mix leaded with the highest octane unleaded available. I don't remember the explaination my chemical engineer friend gave. I do remember it made sense once he explained it to me.(he designed refinerys for Exxon)

[Mr.Fixit]

With the price of the ingredients being suggested for homemade octane boost being comparable to bonafide racing gas, I would suggest mixing in a little cs-114 instead of toluine. Mixing different octane grades of gas has always worked out in my experience, and all ingredients are made for use in internal combustion engine, no need to add lube or cleaning agents. So 1/2 93 octane, 1/2 114 octane should be about 103 octane. I do not claim to be a fuel chemist, but mixing race / pump gas I have done successfully when pump gas didn't cut it.

[jrichard]

Gentlemen, PLEASE be careful with Toluene. It *is* a primary component of high-octane fuels and is very unfriendly to your skin and lungs, your car's paint, and it tends to corrode the metal containers it's sold in if not used within a year or so. It's a very powerful solvent. Seems to me it will melt or weaken fiberglass resin, too. Maybe. I'll look into that point. Hardware store Toluene isn't the purest you can buy, but it may be the cheapest. Any good Scientific chemical supply house can get lab-grade Toluene, and it's sold in a better container than you'll see at HomeDepot, and it's much purer, and much more expensive. Adding it to your pump gas won't hurt your engine, if used in moderation. I've used it in motorcycles before, mostly bikes that sat around a lot.

[427 S/O]

Dr. Dee, can you post Smokey's formula?/

Thanks.

[justa6]

I think if your read the label carefully you'll find ANY octane booster that is added in ounces will raise you Octane by a certain number of Points. Points are 1/10 of an Octane.

ie if the booster raises your octane by 4 "points" then your 93 octane is now 93.4.

There is no "additive" that added at 1oz per gallon will give any meaningful rise.

Toulene is added by the oil companies to get the high octanes along with Xylene and MTBE (Methyl Teretiary Butyl Ether)

If the oil companies have to use the above in fairly high percentages then there simply is no "magic bullet"...

I've been using toulene or xylene in both my Grand National (Turbo) and my Cobra that has 11.5 to 1 compression. It works very well at around 10 - 15% mix. I switched the GN to Alcohol injection and that also works great and is simpler.

I've given a lot of thought to buying a 55 gallon drum of racing fuel and simply mixing it but I hate to have that much gas in my shop. I guess I'll keep mixing the toulene/xylene for now.

By the way make sure if you do this that you premix it in a gas can first. Then put it into the tank "carefully". I don't use the mineral spirits or trans fluid that some people do as the mix is low and the 93 octane already has cleaning agents and lubricants. So I don't worry about it and have never had a problem.

Regards,

[got snake?]

On a side note...Justa6 you said my two favorite words...

Grand and National! Its spring time and they are coming out to play. Something about a JET BLACK sleeper....

GS

[Jack21]

Some suggestions. I wouldn't consider myself a fuels chemist, but I am a hazardous materials chemist with 30 odd years work in the field. And a car crafter (Hot Rodder if you're over 50)

High compression motors and available fuel.

Or perhaps you've played with the numbers on Dyno 2000. Two identical engines. One running 9.5:1, and one with 11.5:1. Everything else being equal, which will be the faster car.

But we can't get Super Shell, or Sunoco 260 at the pump anymore (much less for $.32/gal). But when you try to run it on 93 octane pump gas, it rattles like a coffee can full of ball bearings.

Toluene and xylene are both used in carburetor cleaners. Not sure there's any anti-knock benefit. Moth balls were used for this at one time with dubious results.

Things NOT to burn in your expensive race engine. Laquer thinner, mineral spirits, diesel fuel, automatic transmission fluid. Or any other concoctions or home brews unless the person doing the brewing knows what he/she is doing.

And no MoS2 (molybdinum disulfide) or teflon in the oil. Mos2 is a cam lube, and helps for engine break in. So does GM EOS. After break in, it's no help.

Although polymer coating high frictionengine components is a different story, it can't be done by pouring it in the crankcase.

Like the man said, there's no magic bullet for ping profing your 11:1 motor except the stuff that was designed for it in the first place. Racing gas. Union76 has it. Many speed shops have it. Start with a ratio of 1/10 racing fuel and 93 octane, and up the ratio until the engine smooths out. Upping the ratio any more is like running your grocery getter on 93 octane.

I've never tried aviation gasoline mixtures so can't personally say if it works or not.

[justa6]

The Xylene and Toulene "concoctions" were done by a guy who works in the chemical department for one of the Major oil companies. ie he is in the business. I don't remember where I read it but I think it was on the Buick Turbo web site where the original "recipe" came from. He basically stated that the oil companies use the above compounds along with MTBE to increase the octane when they need to. Of course they also add other chemicals for cleansing and lubrication.

Remember, virtually all new cars and trucks have the fuel pump (plastic) suspended inside the fuel tank. So the oil companies have to take into cosideration that fact along with the fact that the modern fuel pump is very small and has to pump a lot of pressure for the Fuel injection. The pump on my Grand National will see 36 psi PLUS what ever boost I'm running. So if its 24 lbs of boost the pump is putting out 60 psi at a very high flow rate. ie its working very hard. And it needs to do this (on a stock motor) for over 100,000 miles. So lubricants and other additives have to be added.

However, for my Cobra that runs 9psi fuel pressure, has an external fuel pump, and will probably see 3k miles per year its a different game.

Bottom line is if your running more than 9:1 compression you need to do "something". You can run race gas. Works great, is expensive and inconvenient for most of us. You can waste your money on over the counter products that will pick you up 3 or 4 "Tenths" of an octane for 4 bucks or so. You can do some mixing like I do. Or you can run alcohol injection like I run on the Grand National. That system is excellent and anyone interested can email me for the system and it is very high quality and proven by a LOT of Buick guys.

That's about the jist of it except to say that if your running any kind of blower/turbo you had better think about fuel as the pistons don't like detonation when on boost. Been there/ done that

Regards,

[Wayne Maybury]

This subject was discussed in quite a bit of detail last year under the thread title of Octane Additives. Do a search and read the whole story there.

At that time I contacted a petroleum engineer that confirmed that pump gasoline contains up to 30% toluene which does boost octane. He suggested that using any sort of lacquer thinner, etc could be very bad for the various components in the fuel system.

One final point, I believe that MTBE is added to gasoline as an oxygenate, not as an octane booster, this has to do with trying to make the fuel burn as cleanly as possible. California was expected to make a ruling on banning MTBE back in April but that has been put off for a year. All expectations are for the MTBE to eventually be replaced with ethanol. The problem with MTBE is that it is showing up in ground water.

Wayne

[justa6]

Re: MTBE

I think you'll find that MTBE actually does raise octane but not quite as much as Toulene/Xylene. But according to what I've read in 3 different articles it makes the gasoline burn better and produce more energy. Many people think that higher octane fuels are more "powerful" than low octane when it could be argued that low octane is more "explosive" and that is why you need something less volatile to resist detonation. ie harder to self ignite. I'm sure its much more complicated than that though.

In closing this is an important issue for Cobra owners as a lot of the motors used are either right at or over the edge of being able to use normal high octane gas available at filling stations.

Of course, I can't tell if my car "pings" as the side pipes are so loud and from years of flying jets my hearing at the higher ranges is pretty much gone. On the other hand when the Grand National "pings" when on boost it sounds like a baseball bat hitting a drum and a deaf person would hear it.

Regards,

[Steve R]

Bob,
Livorsi Marine sells a knock sensor and indicator. Couple that with their EGT pyrometers, and you can get allot of useful info for experimenting with fuels. Http://www.Livorsi.com
Steven

[Robert T. Day]

Bob-
That alcohol injection system that you have in your Grand National
wouldn't by any chance be made by Edelbrock, would it??

I installed a similar system in my '77 Celica GT(I was all set to put a turbo in it,and already had a header and an aftermarket exhaust system,before that idea died when I got married, and spent money on a wedding ring instead )

Bob

[justa6]

Thanks for the info. I have both a Knock sensor and EGT gauge on the GN as when you have a turbo motor you need to keep track of what is going on with the EGT and Detonation. However, on the normally aspirated Cobra I don't have any of that. The Cobra is 11.5 to 1 compression and I have had no problems with it as I run my Toulene/Xylene mix at 10-15% and it works fine. At the races I put in 116 octane on top of my "mixed" fuel and eliminates the problems.

Re the Alcohol setup on the Buick it isn't an Edelbrock setup and its made specifically for the GN. I've been thinking about getting an alcohol setup for the Cobra so I can simply put 93 octane in the tank and forget about mixing. Still up in the air about doing it though. How did you like the Edelbrock setup?

Regards,

[427sharpe]

Having read thru this thread, I just have one question. Has anyone actually asked what benefit they think they see in 'race ' gas?? At many of the SAAC conventions, race gas suppliers had made a small fortune selling their wares to those of us who campaign our Shelby's (as I do with my GT350). As a test, SAAC gathered 12 seriously campaigned cars and let everyone run with 93 pump and the 110 race. Cars were run in 10 lap tests, with tuning sessions between heats. Cars ran 'blind' to the DRIVERS--ie, they didn't know what the car was using, they just gave driving impressions after each 10 lap sessions. After 5 sessions, lap times were tallied, and heats were examined. End result, NO DIFFERENCE. In the end analysis, they found that a properly tuned car on 93 Octane pump gas ran just as fast as a properly tuned car on 110. I really don't see problem with an 11.5:1 sideoiler running 93. Many of the SB GT350's are running much higher compression, and still use 93. Rick Kopec runs his R Model very hard at SVRA and SAAC runs, and runs pump gas. My BB runs 11.5:1 on 93 octane (but the 429 series can run more squeeze than the 427's without detonation). I would suggest that if detonation is a problem, you retune the motor, or as a last resort run water injection (Edelbrock) to cure it. In either of these scenarios, you can save the motor and your wallet.

[justa6]

Hi,

There is no doubt that if you don't need race gas then your better off with 93 octane. BUT, IMO, there is no way to run high compression off of 93 octane. IF it could be done then the new cars light the Corvette, Mustang, etc would do it. Again, in my opinion, there is simply no way that you can go over around 10 to 1 compression on any 93 octane. You might be able to "trick" the car by really retarding the timing but it wouldn't run very well that way. And in fact to even get to 10 to 1 you'd need aluminum heads.

If you do have 12.5 to 1 and are running true "pump gas" you are going to put a hole in one of your pistons, soon...

It will be interesting what others say about this subject.

Regards,

[DAVID GAGNARD]

Gotta agree with Bob on most all points....My 65 Fastback runs a 351-W,10.4 to 1 calculated compression,iron heads,93 octane,no problems,once I tried 89 octane and the valves rattled worse than a diesel....By retarding the timing it would quit pinging,but would run like crap....

Back in my dirt track days,we had to run "pump gas",93 octane max.,they checked the gas after the feature race. One race motor I built was 12 to 1 compression and we added our own "mixture" to it to get by,got caught one night and we were disqualified for illegal fuel.Next week out they checked us before,during,and after the heat race and feature.We ran pump 93 octane that night and it still ran pretty good so we kept running it. With open headers you cannot "hear" detonation,but after the second night out I new we had it. Pulled a compression test next day,then the head and found most of the lands on two piston gone...Since then we never ran more than 10.5 to 1 compression on pump gas and had no problems......

David

[427sharpe]

Again, too many hard runners in SVRA ARE running pump gas to good effect, and my BB has been alive and well for many years. If, during motor assembly, you pay attention to quench and flame travel you CAN tune a motor to run VERY well on straight gas. NASCAR would be a prime example that seems to be overlooked by most. While I would not suggest trying to get 750 hp out of 358 cubes for the street, the fact remains that with proper tuning and assembly ANY motor will deliver excellent power. Having said that, if you take the old approach and build a 60's motor, yes, you will need 60's fuel. Set up to modern engine building techniques, boys! Again, using the NASCAR example, remember that most engine builders in that arena run LESS than 11:1 compression to achieve the hp numbers they do in race motors. Food for thought. They idea was brought up about claimer engines, etc...Do you think EVERYBODY else was running doctored gas, or do some just have more modern engine building techniques to get more power and stay within the rules? Without going into a diatribe on motor building, remember that detonation is caused by HOT SPOTS in the combustion chamber. Usually caused by inadequate quench, burrs in the chamber or excessive carbon build up. If you clean the casting from sharp edges and excessive roughness (NOT THE SAME AS POLISHING!) and keep the combustion chamber CLEAN of carbon buildup you will be surprised at how much power you can make on 'pump' gas. I suggest a trip to a SAAC or SVRA National will open your horizons a bit. Also, remember that NEW CARS (Cobra, Corvette, Ferrari, etc..) ARE designed to run on 93 octane, and deliver power AND reliability...again, modern techniques yield modern results.

[justa6]

Hi again,

Just so you understand. My motor IS a Busch Nascar motor. It has one of the best combustion chamber designs around. That is why it puts out 473HP out of 274 cubic inches. That is a little over 1.7 HP per cubic inch. That is with only a singe 4 barrel carb. The heads are aluminum. That HP per cube would equate to your car putting out 910HP on a 4 barrel. Look at "View my Photo Gallery" on the left side of the page and take a look at the motor we are talking about.

There is no magic in this area. The best combustion chambers in the industry are probably the Japanese high performance bikes and they can get away with around 11 to 1.

Don't know how your motor is doing it but I can tell you that over 10 to 1 isn't going to hack it on 93 octane without some kind of help.

My opinion only but its based on a lot of different kind of racing with very good equipment.

Regards,