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After reading the other thread and thinking about what GN7 was saying I was just curious.
It's obvious there are many diffrent race fuels , I am just wondering about gasoline.
 

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After reading the other thread and thinking about what GN7 was saying I was just curious.
It's obvious there are many diffrent race fuels , I am just wondering about gasoline.
I'm just going to throw this out there, please don't take offense.;)

The energy content of a fuel has little to do with how much horsepower it can produce, in fact quite the opposite.

For an example, octane rating (how controllable a substance burns) has way more to do with it than anything else....

Gasoline has a BTU content of approx. 18,500 BTU/lb., whereas Methanol has approx. 9500 BTU/lb and can make quite a it more power, just need more fuel, now Nitromethane contains approx 5000 BTU/lb...

So I guess to answer your question, you will be at approx. 18,500 BTU/lb with race fuel, that number really does not go "up" as the grade of fuel is increased, but rather "down"....

Does that even come close to answering your question...:)Unsure

Makes little sense if the basics aren't followed, knowhatamean?;)

GT :)hand
 

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After reading the other thread and thinking about what GN7 was saying I was just curious.
It's obvious there are many diffrent race fuels , I am just wondering about gasoline.
This gets tricky because the highest energy is usually measured in BTU's by weight. Hydrogen wins that contest, but just a wee bit tricky when trying to control it's ignition point (ever read about the Hindenburg?).

Gasoline has a fraction of hydrogen's energy by weight, but gas is less finiky that hydrogen and can be formulated to ignite at different temperatures so it starts to burn just when it is desireable to do so, just like methanol is less likely to pre-ignite than gasoline, and so on.
 

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Race Gas Article

This subject comes up often, so I thought I'd post an article I wrote for a couple drag racing mags a few years back. I had help on this article from a chemist at VP racing fuels. He also reviewed it for technical accuracy. It ran at different times and in slightly different formats in Super Stock, Bracket Racing USA and IHRA's Drag Review. Sorry, the pictures referenced in the article aren't included.
With a cocktail, you should be asleep before the second paragraph.... enjoy.

Racing Fuel Basics
by David Poffenbarger

Racers all know that high performance engines require special fuel. High compression ratios, combined with lean air/fuel mixtures and advanced ignition timing, all create circumstances in which detonation can occur. For many applications, high octane racing fuel is required to provide maximum horsepower and to avoid potentially engine damaging detonation. But will a bracket racer benefit from the same high octane racing fuel? Just how high an octane rating does a bracket racing engine require?

Most racing fuel manufacturers try to provide as much usable information about their products and their applications as possible. However, what do all these numbers mean and how does a racer use them? In this article, we will try to provide a working knowledge of what racing fuel really does for an engine and, at the same time, dispel as many of the myths as possible.

How Racing Fuel is Made

At the refinery, crude oil, taken from deep under ground, is distilled into a wide range of petroleum products. On one end of the spectrum are the very light, high quality petroleum products like natural gas and butane. On the other end of the scale are heavy products such as asphalt. From this range of crude oil products, race fuel is blended using only the best ingredients possible for racing. However, like chefs following a recipe, there are as many ways for the product to turn out as there are refineries blending racing gas.

A particular race fuel may contain anywhere from 50 to well over 100 individual ingredients in a particular blend. However, for discussion purposes, the ingredients can be broken down into three families of hydrocarbons: aromatics, olefins and saturates. Olefins, while commonly used in pump gas, are only present in trace amounts in racing fuels. Saturates constitute the primary family of ingredients in modern leaded racing fuel, usually accounting for 75% or more. Aromatics are also used, but usually only consist of 25% or less of the total make up of a particular fuel.

A more useful way of looking at the ingredients that make-up a racing fuel is by weight and the temperature at which the ingredients vaporize. The lightest ingredients, based on molecular weight, are the most volatile and are called front ends or light ends. The front ends vaporize at the lowest temperatures, usually under about 130 degrees. As the ingredients become heavier and vaporize at a somewhat higher temperature, between about 130 and 250 degrees, they are called medium fractions. Heavy fractions vaporize above 250 degrees and, obviously are the heaviest. Most manufactures provide this information for their fuels in the form of a distillation curve. More on distillation curves later.

The medium and heavy fractions contain most of the thermal content of racing fuel. This thermal content, measured in British Thermal Units (BTU’s) per pound of fuel, is what’s released as heat when the fuel is reacted (burned) in the combustion chamber. As the fuel is reacted, it expands rapidly, pushing the piston down and creating the work that ends up being horsepower.

The medium-to-heavy fractions also have the highest octane values. Considering this, it may seem that the fuel that would make the most power would be that with the most heavy fractions. The drawback to that idea is that, since heavy fractions vaporize at the highest temperatures, they are the hardest to react. This is where the light ends come into play.

The light ends in racing fuels are the most volatile and vaporize at very low temperatures. They are necessary to begin the reaction that burns the heavy fractions and releases the energy in the combustion chamber. They are also necessary for starting a dead cold engine. Think of front ends as the lighter fluid that starts the charcoal briquettes in a barbecue. However, light ends contain little thermal content and, by themselves have relatively low octane value.

Octane

When bench racing gets around to fuels, discussions about what octane is and how much an engine needs top the list. However, most racing fuel vendors will tell you that octane is one of the most misunderstood concepts in racing. Octane is not a fuel additive or even a substance. Octane is strictly a scalar that indicates a fuel’s resistance to detonation. Octane is to fuel as pounds are to weight and feet are to distance.

The test procedures used to calculate octane were developed in the 1920’s and are same ones still used today. For street use, the octane rating gives the average consumer the information necessary to choose the correct fuel for the family sedan. Even for racing, octane rating is one of the important numbers used in choosing a racing fuel. However, a high octane rating isn’t all there is to selecting the correct race fuel for a particular application.

Octane rating is usually expressed in one of three different ways. Research Octane Number (RON) is calculated using a single cylinder engine run at 600 RPM and will generally provide a more generous octane value than does the test that calculates the Motor Octane Number (MON). MON is tested similarly to RON with the exception of being at 900 RPM. MON is generally regarded as the preferred measure of octane rating for use in racing engines since it more closely simulates the types of conditions found in racing. The third value is R+M/2 value, which is the average of RON and MON. This value is what is seen on the yellow stickers attached to fuel pumps in service stations.

By itself, a high octane rating doesn’t add any horsepower to an engine. What high octane ratings do is allow the engine builder to use higher compression ratios with advanced ignition timing that would detonate using lower octane values. However, using a higher octane value than an engine requires, while doesn’t hurt performance, it also doesn’t help it either. If an engine only needs a fuel with an octane rating of 110, spending the additional money to purchase 118 octane racing fuel is a waste of money. Consider that 118 octane racing fuel can cost upwards of 3 dollars a gallon more than 110 octane, and it becomes obvious that the difference could be a significant amount of money over the course of a racing season.

Another common misconception is that higher octane ratings react (burn) at a slower rate. This is incorrect. A fuel’s octane rating has nothing to do with how quickly it will react in the combustion chamber. It should be noted however, that different fuels can have different rates of reaction (flame speed) within the cylinder. The distillation curve will provide hints as to how a fuel will react in use. More on that soon.

When a racer requests information on a particular fuel, the vendor will usually supply a data sheet that contains its octane rating(s) plus a lot of additional information. Understanding this information is an important step towards making informed choices on a fuel and even more important if a racer gets caught short of fuel and must use another vendors wares. Lets look at some of these numbers and what they mean.

Distillation Curve

The previously discussed fuel distillation curve is an important piece of information provided by most racing fuel manufactures. This curve is derived by heating a sample of a fuel and measuring the temperature at which it initially boils and at each point where the volume is decreased by a 10% increment until the sample is gone. Finally, the solid residue is weighed to determine its percentage of the initial sample, which are usually negligible in racing fuels. Figure 1 contains a few of the distillation curve points for three different fuels.

The distillation curve provides an approximation of the fuel’s distribution of front ends to medium and heavy fractions and the temperatures at which they vaporize. Knowing this is important because a fuel must be vaporized before it can be reacted. One of the things to look for in the distillation curve is for the fuel to vaporize relatively evenly over the temperature span. This will contribute to a more complete reaction of the fuel in the combustion chamber.

Most racing fuels have an initial boiling point of around 100 degrees and a final point of approximately 250-300 degrees. If a fuel’s maximum vaporization temperature is to high for a particular application, all of the fuel may not be vaporized in the combustion chamber leading to an incomplete reaction. If the initial temperature is to low, the engine may be prone to vapor lock. If the initial temperature is to high, the engine will be hard to start, although, this varies somewhat with application. A nitrous application for example, may not need a low initial boiling point because of the additional cooling from the nitrous. Turbo-charged or supercharged applications may require a higher vaporization temperature because of the additional heat in the intake tract. What’s important is that the distillation curve provides a lot of information that can be used to help determine the correct fuel for a given combination.

Reid Vapor Pressure

Another value usually included in fuel manufacturer’s literature is Reid Vapor Pressure (RVP). RVP is a measure of how much pressure will result from heating a sample of race gas inside of a confined space. This information is another way of determining the amount front ends are in a particular blend of race fuel. Pump gas typically has RVP’s in the 7-13 PSI range, depending on season. The RVP will be higher in the winter and lower in the summer. Racing fuels typically have RVP’s in the 5-8 PSI range and don’t change with the seasons like pump gas does. High RVP values suggest the fuels use many volatiles in the blend, which can cause an engine to be prone to vapor lock. Low RVP’s can make the engine hard to start in cold weather.

Specific Gravity

A fuel’s specific gravity is a measure of how much a volume of fuel weighs when compared with the same volume of a standard liquid. Water is the standard liquid for comparison to fuels. Therefore, if a fuel has a specific gravity of 0.750 it weighs ¾ as much as an identical quantity of water. Racing fuels can have a specific gravity from a low of about 0.660 through a high of about 0.780, which is a significant difference.

The tool used to measure specific gravity looks like a thermometer that partially floats when dropped into a volume of fuel. The specific gravity is read off graduations on the outside of the bulb. These tools are relatively inexpensive and can usually be purchased from well-stocked fuel suppliers or chemistry supply houses like Cole-Parmer.

Knowing the specific gravity of the fuel a racer is using can be important to help determine how to re-jet the carb when a fuel change is made. Since jets meter by volume, if a lighter fuel is used, it will usually require a larger jet to maintain the correct air/fuel ratio. This phenomenon can also be seen by measuring the effects of heat on the specific gravity of a fuel. As fuel becomes warmer the specific gravity decreases. Most racers understand the effects of hotter weather on jetting and a fuel’s specific gravity is another indicator of this relationship.

Another use for measuring specific gravity is to check for stale fuel. If race fuel is stored improperly it can become stale. Racing fuel should be stored in sealed metal containers in a cool location out of direct sunlight. If race fuel is stored properly, it can last indefinitely. However, if fuel is left in fuel jugs inside a racer’s trailer, where temperatures can reach in excess of 100 degrees, the front ends of the fuel can begin to vaporize. When the jug is opened, this vaporized fuel will vent to atmosphere and is lost. As the front ends go away, so does the fuels ability to react the heavy fractions and power will suffer. This loss of front ends will show up as a slight decrease in the fuels specific gravity and is another reason to test this aspect periodically.

Heat Content

A fuel’s heat content, measured in British Thermal Units (BTU) is another number sometimes thrown around in bench racing sessions. However, the reality is that there isn’t a significant difference in BTU content between various racing fuels. Most racing fuels have a BTU content of around 19,000 BTU per pound (surprisingly, this is about the same as pump gas as well). Since race fuels weigh approximately 6 pounds per gallon, this equates to around 114,000 BTU per gallon. Based on percentages, even an increase of 1000 BTU per pound is a relatively small increase in thermal content at the carb jet.

Another common misconception is that heavier fuels, those with a high specific gravity, have a higher BTU content. Again, this is not necessarily true. The chemists that brew racing fuel have ways of juggling a fuel’s specific gravity and BTU content to accomplish whatever goal they are after. Consider the BTU content of the fuels in Figure 1. C-14 is the lightest fuel, based on specific gravity, however it has the largest BTU content.

What is more important than BTU content in making horsepower, is the ability to release as much of the thermal energy as possible. This gets back to knowing how and when the fuel vaporizes relative to ignition and reaction.

Race Fuel Myths

A couple of the myths surrounding race fuel have already been discussed concerning what octane is and isn’t and its relationship to fuel burn rate. However, a couple more myths are worth discussing. Racing fuels are often compared by how they will affect an engine’s exhaust gas temperatures (EGT), suggesting that raising or lowering EGT’s is a good thing. Given that the BTU content of most racing fuels is not significantly different and that when reacted, they will burn at approximately the same temperature, it is very unlikely that a fuel by itself will have significant effect on EGT’s. An engine’s EGT is a function of many different factors; it’s basic design, ability to breath, ignition timing, and valve timing. Additionally, it takes a significant amount of dyno testing to determine what a particular engine’s ideal EGT should be. So to suggest one fuel is better because of its effect on EGT is gross oversimplification.

Another myth is that race gas can be doctored by home “chemists” to make significantly more power. Most racers have heard the old wives tale that a handful of mothballs thrown into the fuel will really wake up an engine. Unfortunately, it usually doesn’t work quite like that. While there are a few commercially available additives that do add horsepower, most come with either significant risks to a racer’s engine or personal health, or are expensive, or both. It’s important to remember that there are a whole bunch of well educated and talented people working for racing fuel manufacturers who are constantly looking for ways to improve their fuels. If there were a safe and reasonably priced additive that would create more power in a racing engine, they would be using it. Trying to doctor fuels at home is taking unnecessary risks. Leave this to the chemists and engineers working for the manufacturers.

How to Choose a Racing Fuel

So far, we covered the science side of racing fuels, but how does a racer choose a fuel for their car? Is racing fuel even required for all applications?

To answer the second question first, serious bracket racers concerned with every thousandth of a second in consistency should consider using race fuel. Even if a particular engine application could run on pump gas, the regional and seasonal variances in the blending of pump gas can lead to inconsistencies in engine performance. Pump gas purchased in a metropolitan area of California in the winter can be significantly different than the same brand purchased in the Midwest during the summer. One of the benefits of race gas is the consistency in the blends and that alone is a good enough reason to use it.

OK, we know we need to use race gas, so which one is best. There are several factors in deciding on a race fuel. First, if you don’t build your own engines, talk to your engine builder and get their recommendation. But don’t stop there. Also talk to the manufacturers of the fuels that are readily available in your area. Fuel manufacturers have tech-support people who know racing and can advise racers on which of their fuels will best meet their needs. They will want to know some things about your engine including compression ratio, whether it’s naturally aspirated or blown/turbo-charged and the type of racing you do (in case some non-drag racers are reading this article). Also be certain that the fuel is readily accessible in your area. Finding the perfect fuel and not being able to purchase it readily can be a significant problem.

Once a racer has decided on a fuel that works for their application, stick with it. Keep adequate reserves of the fuel (stored safely, of course) so that you don’t get caught short. Be careful about depending on trackside suppliers. Most that I have worked with are dependable, but being a trackside supplier is difficult and thankless work with little financial reward, so it’s not surprising when one quits. Additionally, the track owner may change suppliers of the track’s “official fuel” on relatively short notice. Be aware of these things so that you don’t get caught short of fuel on race day.

Hopefully, this article has provided the racer with enough background to make use of the information contained in a racing fuel data sheet. If a racer learns as much about fuel as they usually know about engines, the correct fuel can be chosen to make maximum horsepower without the risk of detonation. Discuss any remaining questions you have with your engine builder and fuel manufacturer concerning your application. Once the correct fuel is found, stick with it and take advantage of the consistency that racing fuel manufacturers go to great lengths to maintain. Accomplish this and you will have one less thing to be concerned with on race day and you will be the racer in the know during those all-important bench racing sessions.



The writer would like to express his gratitude to the fine people at VP Racing Fuels, San Antonio, TX (210-635-7744) for their patient assistance in researching this article.






Figure 1

Here are most of the properties that are typically provided on a racing fuel data sheet for 3 different fuels. Data courtesy of VP Racing Fuels:

Property VP Red C-12 C-14

Specific Gravity .742 .709 .694
Reid Vapor Pressure, 7 PSI 7.75 PSI 5.5 PSI
BTU’s, per pound 18,800 18,834 19684
Distillation Curve (in degrees)
Initial Boiling Point 127 98 130
10% 170 129 170
30% 202 165 NA
50% 218 196 200
90% 288 228 212
End Point 348 240 232
Motor Octane Number 105 108 114
Research Octane Number 110 110 114
R+M/2 107.5 109 114
Color Red Green Yellow
 

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David,

I did not "quote" your post because of it's shear size, but...

Good read!, thank you for posting...

I was paraphrasing...But "Right click save"...Thanks again!:)devil

GT :)hand
 

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David, if you wrote that, you are to be commended. Its excellent. And very informative. However, I don't know exactly when you wrote that, and I have a couple of things that may have changed slightly since you wrote that. First it states that pump gas has pretty close to the same heat content(BTUs) as race fuel. I will claim, it USE TO. And in some areas, during certain times of the year, depending on the seasonal blend. But the more more ethanol they jamb in it, the more you better flow to get the energy back. And as of today, it contains ethanol more than they are willing to admit to. Quick fuel make a little tester for pump gas containing ethanol to tell you the alky content. 15% is not uncommon. Its suppose to be not more than 10%. But they have their reasons for raising it, and they get away with it. Do really believe if you were to fill your tank with e-85 with no jet changes it would make as much power as straight 100% gasoline. Hell no! Jet it right, squeeze it a little more and now your are getting somewhere. But you have to flow MORE! Think you don't have to flow at least a little bit more with pump containg 10% as advertized. And if is actually 15%? Of course you do. Know any body with aboat that is measuring the alky content of pump to determine there jets sizing each time they fill up. Pump gas totally sucks not because it doesnt contain as much heat per lb, and today it doesn't, but because they constantly jack it around at will, and they are allowed to. Todays gas could not even be sold as gasoline under the federal laws of 1965.
As for race gas, well there are some things going on out there that don't necessarily raise the heat content per lb, but there sure are some things that allow you to burn more lbs if they weren't in there. I know, I tried it. It doesnt take a genius to know what is going on. How they do it is a little trickier. And most of these aren't allowed by alot of sactioning bodies. Why do you think there is a spec fuel for Pro Stock in the NHRA but not for say...Quick 16. Because they don't want a fuel war that they would have to monitor. Seen an APBA rule book regarding fuel. Its scary. Use "this", suspended for the year, use it again, banned for "LIFE". The list is in the APBA rule book, and I don't believe any of the stuff on the list adds one BTU to the show. They just let you add a shit more fuel. So when I posted on another thread about heat content, I should have clarified that it wasn't "heat per pound but more like the LBS BURNED. Its so bad in F1 now, Shell is blending fuel for each team for each track. And none of it is probably actually "gasoline" by definition.



 

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That was a great write up David.
So what is it that happens with gasoline when the octane rating isn't enough for the compression, and detonation results? What "detonates"?:)bulb;)
 

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Does anyone have any information on the new breed of oxygenated fuels. Seems as if there might be something to them. Last season my buddy Tony won 5 gallons of it at the Ming money race. The following month he used it on his last pass on Sunday. It was his last pass because the boat picked up nearly a tenth and he broke out. Anyone else have any experiance with it?
 

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Nope, never ever tried it. Never, I swear. And I nothing I wrote is to be in any way to be regarded as refering to them. In no way was I trying to say that they allow you to burn more fuel and create more heat.



 

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David, if you wrote that, you are to be commended. Its excellent. And very informative. However, I don't know exactly when you wrote that, and I have a couple of things that may have changed slightly since you wrote that. First it states that pump gas has pretty close to the same heat content(BTUs) as race fuel. I will claim, it USE TO. And in some areas, during certain times of the year, depending on the seasonal blend. But the more more ethanol they jamb in it, the more you better flow to get the energy back. And as of today, it contains ethanol more than they are willing to admit to. Quick fuel make a little tester for pump gas containing ethanol to tell you the alky content. 15% is not uncommon. Its suppose to be not more than 10%. But they have their reasons for raising it, and they get away with it. Do really believe if you were to fill your tank with e-85 with no jet changes it would make as much power as straight 100% gasoline. Hell no! Jet it right, squeeze it a little more and now your are getting somewhere. But you have to flow MORE! Think you don't have to flow at least a little bit more with pump containg 10% as advertized. And if is actually 15%? Of course you do. Know any body with aboat that is measuring the alky content of pump to determine there jets sizing each time they fill up. Pump gas totally sucks not because it doesnt contain as much heat per lb, and today it doesn't, but because they constantly jack it around at will, and they are allowed to. Todays gas could not even be sold as gasoline under the federal laws of 1965.
As for race gas, well there are some things going on out there that don't necessarily raise the heat content per lb, but there sure are some things that allow you to burn more lbs if they weren't in there. I know, I tried it. It doesnt take a genius to know what is going on. How they do it is a little trickier. And most of these aren't allowed by alot of sactioning bodies. Why do you think there is a spec fuel for Pro Stock in the NHRA but not for say...Quick 16. Because they don't want a fuel war that they would have to monitor. Seen an APBA rule book regarding fuel. Its scary. Use "this", suspended for the year, use it again, banned for "LIFE". The list is in the APBA rule book, and I don't believe any of the stuff on the list adds one BTU to the show. They just let you add a shit more fuel. So when I posted on another thread about heat content, I should have clarified that it wasn't "heat per pound but more like the LBS BURNED. Its so bad in F1 now, Shell is blending fuel for each team for each track. And none of it is probably actually "gasoline" by definition.
Yea GN I actually wrote every single word. It ran in the magazines I stated and I was paid for each use. An Australian version of National Dragster stole it and ran it as well though they gave me writing credit. I have copies of most of the actual mags my stuff ran it... If I get ambitious, maybe I'll scan in the actual article out of the mag for the doubters out there.... Of all the articles I wrote, this one on race fuel, one on racing torque converters and another on cylinder head flow were the hardest to write and the one's I'm most proud of. I think I've had about 100 articles published, almost all hard core tech.
You are correct though, I did that write up before alcohol became common place in pump gas. Also, I chose to avoid discussing the "cheater" fuels because the article was focused on bracket racers and fuels readily available at that time. Also, VP helped a lot and they really wanted to avoid this discussion in print.

That was a great write up David.
So what is it that happens with gasoline when the octane rating isn't enough for the compression, and detonation results? What "detonates"?:)bulb;)
A bomb :p

Does anyone have any information on the new breed of oxygenated fuels. Seems as if there might be something to them. Last season my buddy Tony won 5 gallons of it at the Ming money race. The following month he used it on his last pass on Sunday. It was his last pass because the boat picked up nearly a tenth and he broke out. Anyone else have any experiance with it?
Lots of mixed reviews on this stuff. I haven't messed with it and most of the guys around shop I race out of are not fans. I've got my hands full with learning how to race with straight methonol so I'm not gonna be any help with that.
 

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Hey GN

"If you wrote that" suggests you doubt my material's authenticty. Suggesting someone put their name to published material they didn't write is theft (plagerism). This would offend any writer, me included.
You don't know me but I'll tell you straight up, I can prove ANYTHING I say I've done. I don't BS and making statements like the one above is why you piss so many people off around here. I'm very capible of original thought and I'm better than most at articulating it in word.

 

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David,

I wasn't going to question whether or not you wrote it but I did want to know why you didn't mention AV Gas :p

So could you write another piece on VP- 110, C-12 vs Av Gas in a 13:1 engine ? I'd like to hear/see what the outcome would be. :)bulb

Sleeper CP ;)

I see why you took GN's question as a "slight" I actually read it twice to see what he meant. Maybe he didn't mean it that way ?
 

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"If you wrote that" suggests you doubt my material's authenticty. Suggesting someone put their name to published material they didn't write is theft (plagerism).
Not at all. if it came across like that, I apolagize. Like I said, you are to be commented, and it was very informative. Great piece of work. Get off your ass and to some more, there aren't enough articles like that:D



 

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Doesn't AV gas have plane specific additives such as de-icing agents? I wouldn't run race gas in a plane or plane gas in a race motor.
I was only 1/2 joking. When the 565 get's freshened up with new pistons I actually plan of doing a C-12 vs 3:1 AvGas/pumpgas mix run on the dyno. The last I did it I think in '95 the race gas made 5 more hp. 855 vs 850 without a jet change or timing change. That engine was 10.8:1. When I get new pistons they probably be close to 13:1

I never gave running av gas another thought after Bruce Crower told me not to worry about it under 13.5:1. When I do it I'll post the numbers. But hell I'll need new pistons first. I have other things to tackle first.

Sleeper CP
Big Inch Ford Lover
 

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People running AV gas in boats and cars has been going on for decades, but logically to me if you have gas brewed specifically for planes, vs gas brewed specifically for high compression racing engines, I'm gonna take the one made for my application. I know next to nothing about the AV gas, but I know there are several vendors of racing gas making it easily obtainabale. The only thing I can think of being a lure to use AV would be price maybe???
 

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David,

I wasn't going to question whether or not you wrote it but I did want to know why you didn't mention AV Gas :p

So could you write another piece on VP- 110, C-12 vs Av Gas in a 13:1 engine ? I'd like to hear/see what the outcome would be. :)bulb

Sleeper CP ;)

I see why you took GN's question as a "slight" I actually read it twice to see what he meant. Maybe he didn't mean it that way ?
Not at all. if it came across like that, I apolagize. Like I said, you are to be commented, and it was very informative. Great piece of work. Get off your ass and to some more, there aren't enough articles like that:D
Sorry GN, I kinda went into one of those non-linear spikes at the implication. :)st I'm all better now :D

Thanks to all for the kind words and PM's. Unfortunately my writing days are behind me now. I got paid pretty well for those articles, but they are a LOT of work. Knowing guys like CP and GN were gonna be looking at them, I worked really hard to make them as accurate as possible.
At the time I was doing most of the writing, I had just left the corporate world to become an independant consultant. I had a bit of extra time as I was building my clientele and needed the $$$. Towards the end, magazines quit wanting to pay much for these type articles. This was mostly because they could get "free tech articles" from the advertising agencys that represented different mfg's. Obviously, the articles were light on tech content and most were thinly veiled ad copy. Now my consulting business doesn't leave me time to write, even if the mags wanted to pay.
Todd and others who asked about Av Gas. The article was already longer than what the mag wanted and discussing av gas would have added to it. Also, the article was supposed to be focused on readily availble race fuels. Av Gas availablity is sketchy for many and there were no quotable/reliable sources for info.
 

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People running AV gas in boats and cars has been going on for decades, but logically to me if you have gas brewed specifically for planes, vs gas brewed specifically for high compression racing engines, I'm gonna take the one made for my application. I know next to nothing about the AV gas, but I know there are several vendors of racing gas making it easily obtainabale. The only thing I can think of being a lure to use AV would be price maybe???
Just so were on the same page.. You do know who Bruce Crower is don't you ? Talking to him about anything engines is like talking to Chuck Yeager about an airplane...just take his word for it. The other thing about Bruce is that he has 3 airplanes, so he was well aware about the make-up of av gas.

For your typical river racer at 12-13:1 the potential loss of 5-20 hp isn't really going to show up anywhere. just my .02 .....well I did run the 565 for years on av gas and pump gas blend (60/40 blend) for years but it was only 10.8:1 and it did have a 250 shot on it. I do know a guy that ran a 13.5:1 BBC on av gas for 12 yrs with out a problem.

S CP :D
 

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For those wondering what "things" that are being used to up the "performance" of gasoline, heres a short list. Most of these are things you won't be able to get your hands on without a little work, you don't want around your house, wife,and kids, and you most likely have know idea how to use. And I was wrong. The APBA suspension for the first time use is TWO years, second offense is LIFETIME. They are pretty serious about this stuff. Alot of it has to due with the fact that a spill with this stuff in boat racing may very well involve a public water way. Just plain ole cheating gets you disqualified first time, and a suspension for the second. They take this stuff alittle more serious than plain ole cheating.



33.18 The following substances are forbidden to be present in gasoline for health and safety reasons during any APBA event: Acrylonitrile, Aminodiphenyl,
Aniline, Benzene, Benzidine, Beryllium compounds, Bromine compounds, Chloromethyl ether, Chlorine compounds, Ethylene oxide, Hydrazine compounds,
Manganese compounds, Nitrobenzene, Nitrochlorobenzene, Nitrogen compounds, Nitrodiphenyl, Propylene oxide and Tert Butyl toluene. If concentrations
of any of these substances greater than that allowed in commercial gasoline by the current EPA upper limits are found in a gasoline sample, the penalty
will be a disqualification from the race and a two-year suspension. A second offense will result in a lifetime suspension.



 

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People running AV gas in boats and cars has been going on for decades, but logically to me if you have gas brewed specifically for planes, vs gas brewed specifically for high compression racing engines, I'm gonna take the one made for my application. I know next to nothing about the AV gas, but I know there are several vendors of racing gas making it easily obtainabale. The only thing I can think of being a lure to use AV would be price maybe???
Back in our hot ski boat days, guys seemed to have better access to AvGas except for me. I rolled up to the airport pumps with my plastic jugs and they looked at me like I was crazy. They absolutely wouldn't sell it to me. Other guys "knew" people and seemed to be able to get it regularly.
Once we started getting into real racing engines, I thought along the lines of Todd. I wanted the consistancy you get with true race fuels.

For those wondering what "things" that are being used to up the "performance" of gasoline, heres a short list. Most of these are things you won't be able to get your hands on without a little work, you don't want around your house, wife,and kids, and you most likely have know idea how to use. And I was wrong. The APBA suspension for the first time use is TWO years, second offense is LIFETIME. They are pretty serious about this stuff. Alot of it has to due with the fact that a spill with this stuff in boat racing may very well involve a public water way. Just plain ole cheating gets you disqualified first time, and a suspension for the second. They take this stuff alittle more serious than plain ole cheating.



33.18 The following substances are forbidden to be present in gasoline for health and safety reasons during any APBA event: Acrylonitrile, Aminodiphenyl,
Aniline, Benzene, Benzidine, Beryllium compounds, Bromine compounds, Chloromethyl ether, Chlorine compounds, Ethylene oxide, Hydrazine compounds,
Manganese compounds, Nitrobenzene, Nitrochlorobenzene, Nitrogen compounds, Nitrodiphenyl, Propylene oxide and Tert Butyl toluene. If concentrations
of any of these substances greater than that allowed in commercial gasoline by the current EPA upper limits are found in a gasoline sample, the penalty
will be a disqualification from the race and a two-year suspension. A second offense will result in a lifetime suspension.
Yea, pretty much any chemical compound that ends in the letters "ene" and "yl" are gonna be real bad for you. I knew some guys in the early days of NJBA's ski flat class that tried spiking their fuel with propylene oxide. When they got it right it made power, but usually it was off and ultimately ended up hurting their engine...
 
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