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Author Topic: Everything you ever wanted to know about racing fuel  (Read 8753 times)

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #15 on: December 09, 2013, 01:31:55 PM »
this use, indicating by percentage the amount ofNitromethane in the fuel, checked by volume and not weight.

For those unfamiliar with the hydrometer, it is a simple device which uses acalibrated weight to float in the fluid to be checked, the level at which thefloat sits in the fuel indicating the specific gravity of the fuel. As we knowwater is 1, Methanol coming out at 0.79 and Nitromethane at 1.13, it is easy toestablish the fuel mixture.

To avoid having to consult tables or graphs the special hydrometer mentioned isdirectly calibrated, so you just read off the actual content of Nitromethane inpercent.

FUEL TEMPERATURE

It must be mentioned here that the average fuel test hydrometer is calibratedto give a completely accurate reading at one specific temperature, usually 68degrees Fahrenheit. Thus if you check 100 percent Nitromethane solution whichis at 68 degrees Fahrenheit, the hydrometer will give you a reading of 100.

If you mix one gallon each of 100 percent nitro and methanol and thetemperature of this solution remains at 68 degrees your reading will be 50 onthe hydrometer scale indicating that you have a 50-50 mix or 50 percent nitrocontent. Mix any ratio of nitro and methanol with the temperature at 68° F andthe hydrometer will accurately indicate the percentage, be it 10 percent, 40percent, 80 percent or any other ratio.

                             
EXAMPLE: Our tank contains a 55% nitromethane mix and wewish to reduce it to 20% by the addition of straight methanol. On the graphdraw a connecting line between the two percentages to be mixed with the lowestpercentage (in this case 0%) on the left. Where this line intersects therequired percentage line (20%), draw another vertically down to the base line.The number of pints to the left of this line (in this case just under 3) is theamount of the high percentage (55% in our example) required, and the number ofpints to the right of the line is the amount of the lowest percentage (0% orstraight methanol in our case) required. The two amounts will total one gallon.

Changes away from the baseline temperature of the fuel (68° F) will have aneffect on the hydrometer reading. Changes in fuel temperature affect thespecific gravity of the nitro and therefore give you a false reading.

If the temperature drops the reading will be high, giving the impression thatthe nitro content of the mix is higher than it really is. If the temperaturegoes up the reading will drop, causing you to assume that there is less nitroin the mixture than there really is.

Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #16 on: December 09, 2013, 01:50:49 PM »
Here lies. the danger - the natural mistake in thisinstance would be to compensate for the false reading by adding more nitro,with the possibility that your engine may run lean with damaging results.

If you run strictly according to volume (for example mix three gallons of nitroto one of methanol for a 75 percent mix) you'll always be on the safe side.However, unless you want to keep running that same mix, you will either have todump what is left in the tank when you want to change percentage or use ahydrometer.

With the hydrometer however, you can run into trouble, as you will NEVER find alocation where you can guarantee the ambient temperature will be 68°F, and youwill need to measure the temperature of the fuel before attempting to determinethe percentage of nitro it contains.

Whatever the true percentage of nitro in your tank is, it will always returnaccurate hydrometer reading when checked at 68° F. Let the temperature drop to60°F and you'll get a higher reading (82 percent for an actual 80 percent mix;let it climb to 80°F and your reading will drop to 77 percent for the actual 80percent mix.

To combat this problem refer to the accompanying chart which lists actualpercentages of nitro at various temperatures and hydrometer readings. As can beseen the variations in the true percentage are quite significant.

FUEL TEST CHART
Test hydrometer reads 100% at 68° in known pure nitro.
TEMPERATURE OF FUEL- (°F)
[TABLE=class: MsoNormalTable, width: 297]
[TR]
 [TD=width: 50, bgcolor: transparent]  
True % Nitro
 [/TD]
 [TD=width: 334, bgcolor: transparent]  40° 50° 60° 68° 70° 80° 90° 100°  110° 120
 [/TD]
[/TR]
[TR]
 [TD=width: 50, bgcolor: transparent]  
100
 
98
 
90
 
80
 
70
 
60
 
50
 
40
 
30
 
20
 
10
 [/TD]
 [TD=width: 334, bgcolor: transparent]  106 104 102 100 99 97 94 92 90 87
 
  104 102 100 98 97 95 93 90 88 86
 
  97 94 92 90 89 87 85 83 80 78
 
  86 83 82 80 80 77 75 73 70 68
 
  75 73 71 70 70 68 65 63 61 59
 
  66 63 61 60 60 58 56 54 52 50
 
  55 53 51 50 49 48 46 44 42 40
 
  45 43 41 40 39 37 35 33 31 30
 
  35 33 31 30 29 27 25 23 22 20
 
  27 25 22 20 20 18 17 15 13 11
 
  20 16 13 10 10 9 7 5 3 1

 [/TD]
[/TR]
[/TABLE]
ACTUALPERCENTAGES OF NITRO
EXTREMES of temperature can play havoc withnitromethane power output and provide for false hydrometer test readings. Graphabove shows the effects of temperature changes on nitro-completely accuratereadings can only be obtained with fuel at 68 degrees Fahrenheit.

Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #17 on: December 09, 2013, 01:51:26 PM »
KEEP IT RICH

Once again we stress as you increase the use of Nitromethane you must run wellon the rich side, even up to the point of the engine starting to misfire on therun, regarding the cost of the fuel as an insurance against engine failurecaused by the increased power developed as the percentage is increased.

A constant check should be kept on the valve clearances as this will at onceindicate if by any chance a valve is stretching at the neck, both inlet andexhaust being suspect when running at high power levels.

TIPPING THE CAN

AS with the introduction of Methanol, the introduction of Nitromethane fuelmeans that ignition settings will have to be adjusted to take full advantage ofthis volatile fuel.

Starting from the position found most satisfactory for Methanol it will befound that as the amount of Nitromethane is increased so will the ignitionpoint have to be advanced, due to the slower burning of the fuel.

The actual amount will depend on the engine design and will vary from engine toengine, but as a guide could be as much as 60 degrees, and since in fact theamount is not too critical some 40 degrees would be a good starting point.

Insufficient advance is usually made obvious by misfiring under load and athigh engine speed, plus a general feeling of lack of power.

It is almost impossible to state a limit of advance as it varies so much engineto engine, but here again a falling off in power would indicate the limit pointhas been passed.

With very high Nitromethane content fuel the ignition point may well come backto a lower reading since owing to the large amount of oxygen being released themixture becomes more sensitive, the flame pattern changing and the lowersetting more effective.

SAFETY FIRST

Since we are talking about using Nitromethane in fair quantity, once again awarning to use a face mask for the driver when he is situated behind theexhausts and therefore in the fume area.

In certain cases it will be possible to extend the use of Nitromethane untilthe absolute figure of 98 percent is attained, usually regarded as 100 percent,at which stage you really have to pour it in to keep the mixture rich enough asthe fuel itself generates its own supply of oxygen, also at a very high rate.

At 80 percent and above, the optimum air fuel ratio no longer exists and thepower output becomes well related to the actual amount of fuel fed into theengine by weight.

In all the information given the engine has so far been regarded as a normallyaspirated engine, that is unsupercharged, but in fact the use of Nitromethaneis providing chemically similar results to the mechanically superchargedengine, but of course advantage can be taken of both methods together, providedcertain precautions are taken, in particular that of using a suitablecompression ratio.

SUPERCHARGING

If for example the normal compression ratio is 10 to 1, then if we nowsupercharge at some 15 pounds boost or approximately one atmosphere, the totalcompression ratio in effect is now doubled, or at 20 to 1 so far as the fuel isconcerned, but in practice it would not be quite so high as this due to losses,but could well be some 16 or 17 to 1.

We are now at a stage where having started on Methanol and then progressed tothe introduction of Nitromethane, we are starting to consider other possibleadditives to obtain high power at perhaps a lower cost since as yet pureNitromethane is relatively expensive in this country.

OTHER ADDITIVES

Tetranitromethane which is very expensive and almost unobtainable can be used,but requires great care in handling as it has an explosive characteristiccoupled with instability.

Dinitropropane which is solid at room temperature and again normally almostunobtainable, could be however a fairly safe additive and effective.

Isopropylnitrate is yet another very reactive substance, inclined to beunstable and unsafe in unskilled hands, and of course one may add, expensive.

Propylene Oxide has some handling problems in pure state but is quite safe whenblended in other fuels.

Used in conjunction with Nitromethane it helps to increase power as it acts asan ignition accelerator, increasing the flame speed and up to 20 percent may beused.

When used with other fuels up to 5 percent, better starting and smootherrunning are the result.

In practice the usual amount used is some 10 percent as with more than thislevel it is necessary to introduce other components, such as for example, wateror benzole to reduce detonation possibilities.

It is only fair to say that when you get to this stage of mixing up your ownblends of fuel you are, to a great extent, more or less on your own and youbecome part chemist plus mechanical engineer.

Due to the high power levels involved great care must be taken and extremecleanliness is essential.

Yet again do check that at all times your fuel lines

and pump capacity is more than adequate to cope with the heavy extra demand asyou tend to get increased power output from these exciting fuels now available,and once again always tend to run on the rich side, the extra cost of the fuelbeing cheaper than a wrecked engine due to a weak mixture.

CHECK YOUR PLUGS

The only sensible way of increasing the amount of Nitromethane is in smallprogressive steps, and at each step checking the plugs which will indicate whenthe limit for that particular engine is being reached by the following signs:-

1 Chipping of bode insulator, similar to weak mixture.

2. Overheating of all metal parts of the plug, in extreme cases to the externaland exposed body of the plug.

3. The center insulator ashen in color with grey streaks, not to be confusedwith the white grey color of weak mixture.


Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #18 on: December 09, 2013, 01:52:02 PM »
It being assumed at all times there is no question of theengine being on weak mixture and here again we repeat at all times work on therich side.
PRE-IGNITION AND DETONATION


BEFORE we consider the use of other additives to the fuel we must get a clearunderstanding of the problem introduced by two well known conditions thatoccur, especially when you are seeking high performance from the engine, and inparticular using fuel of the type we have been discussing.

We have in mind of course Pre-ignition and Detonation and we did state we wouldexplain these two conditions in detail. Let us therefore look at, perhaps, theeasier one of the two to explain and understand, that of Pre-ignition.

The name itself is self explanatory. The fuel is being ignited before it shouldbe, causing all sorts of trouble. To understand we must go back to our simpleheat engine and once again consider just what takes place, taking thecompression stroke as our starting point, assuming that up to that moment oftime the engine has been running satisfactorily.

That being so, we have the piston commencing to travel up the cylinder bore,starting to compress the fuel ready for ignition by the spark at the plug.

IGNITION SETTING

Depending on the ignition setting, the spark should occur at just the righttime to allow the mixture to ignite, the resultant explosion being so timedthat its force is applied to the piston just as it is ready to commence itsdownward stroke.

As we have explained with Methanol for example, as compared to Petrol, theignition setting point has to be advanced since this fuel is slower inigniting, taking longer to burn, hence the need to commence the operation justthat bit sooner so as to get the force of the explosion at the right momentlooking at it from the piston point of view.

If the explosion takes place too late, then the piston has already started todescend, so the force of the explosion is reduced since there is now so muchmore room so to speak in the chamber.

On the other hand if it occurs too soon, the force of the explosion meets thepiston on its way up the bore, trying to force it down, so power is lost and agenera! state of opposing forces exists.

It is just this that makes it necessary to time the ignition setting to agreewith the type of fuel in use so as to get the maximum effect, also to have anignition system that will ignite as much of the mixture as possible in the veryshort time it has to do so.

DETONATION

Having we hope established a reasonable understanding of Pre-ignition we mustnow turn to the other troublesome condition known as Detonation, which again asits name implies, is an explosive force and as such destructive.

Detonation is caused by the actual compression of the mixture to a level whereit reaches the Auto-ignition point, becoming an uncontrollable explosion, thepoint at which this takes place varying from fuel to fuel, hence the use ofadditives to vary this point.

The explosion takes place without the aid of any local hot spots, including theplug itself, and again is out of time with piston movement.

A further cause and a frequent one at that is a small pocket of fuel, afternormal ignition has taken place, getting further compressed by the explosion inthe cylinder head in addition to that of the mechanical compression, thenigniting, after the normal ignition point, so out of time, causing the wellknown "pinking" effect and in a severe case mechanical destruction ofthe engine.

The amount of destruction is to some extent dependent on the actual shape ofthe cylinder head and the space available for the pocket of fuel to collect.

If the pocket that is formed is relatively large, then the force of this veryhighly compressed fuel exploding can do mechanical damage, but if on the otherhand it is small it may not do so, but it can, and will, form a local heatspot, which in turn will cause pre-ignition.

SPARK PLUGS

Right away the first item that leaps to mind is the plug itself, which afterall has just the essential job to do of igniting the mixture.

If this gets overheated and then retaining the heat, becomes hot enough toignite the fuel itself, without the aid of the spark across the electrodes,then it will do so as soon as the fuel is introduced into the cylinder and isdirected by the upward motion of the piston towards the head and the plug,obviously well before the correct moment of time.

This means that we must be selective in our choice of plug and use the correctgrade, the so-called "hot" type being out, further to that thecondition of the plug must be first class.

It is quite useless and in the long run expensive, to waste time with poorplugs, so just remove the one you pinched from the lawn mower and treatyourself to the correct grade of "cold" plug right away.

ENGINE TEMPERATURE

Let us now assume we can forget the plug situation and say all is well. We nowhave to consider engine temperature as the next possible cause of preignition,or some part of the cylinder head becoming so hot in itself that it acts as theplug, igniting the mixture all out of time with the piston movement.

This means at once forces opposing each other in the engine, producing stillmore heat and so the whole thing getting into a vicious circle.

The obvious possible cause would be weak mixture as a start since this cancause an increase in temperature due to the combustion of the fuel being morecomplete, eliminating the cooling effect of any fuel that may be left over innormal conditions, which in the case of Methanol could well be in liquid form,and sometimes when considerable overlap timing is used, can be seen ejectedfrom the exhaust ports.

VALVES

Remember we did point out that in the case of Methanol you had the advantage ofa lot of fuel being introduced to the cylinder acting as a coolant, to thevalves in particular.

This being so it follows that if you do have a weak mixture, you are almostcertain to have the valves reaching high temperatures, especially the exhaustvalves which in fact can reach a high enough temperature to ignite the fuelthus causing pre-ignition.

Now let us say we have the right plug, correct ignition setting for the fuel inuse and adequate mixture being
Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #19 on: December 09, 2013, 01:52:36 PM »
introduced to the cylinders.

We can still suffer pre-ignition, however should there be a rough part of thehead, say a small ridge by the plug hole, which, since it is so small in mass,can build up and retain enough heat to become a small red hot mass, againtaking over from the plug and doing its work all at the wrong time.

Yet again another cause could be faulty valve operation or incorrect tappetsettings so that the fuel mixture, although in itself rich enough, is unable tobe placed in the cylinder head at the right time, again causing the effort ofthe eventual explosion, when it does take place, to be out of time with thepiston movement.


AUTO-IGNITION

CERTAIN fuels are more sensitive to pre-ignition than others and this is due toa function known as the Auto-ignition temperature characteristic, which in factmeans that once above the flash point of the fuel under consideration, there isa temperature point at which this fuel will ignite, this being the particulartemperature known as the Auto-ignition temperature of that fuel.

Since this point varies from fuel to fuel, it does mean by the choice of thefuel selected for use, plus if required the use of additives, the optimum fuelmixture can be selected to reduce pre-ignition sensitivity by the act ofraising the Auto-ignition temperature point of the total fuel mixture.

In order therefore to take advantage of this information it is necessary toestablish the actual temperature at which the fuel it is proposed to usesuffers from this Auto-ignition characteristic.

Once this information is obtained it then becomes necessary to make quite surethat the temperature inside the combustion chamber does not under anycircumstances exceed this figure, as otherwise we run straight into trouble.

If for example it does, due to the use of a very high compression ratio, wewill, to avoid trouble, either have to reduce this ratio, or use another typeof fuel, or yet again with the existing fuel, use an additive to increase thetemperature point, bearing in mind that the higher the compression ratio usedthe greater the heat produced in the charge, as previously explained whenlooking at our simple heat engine.

In connection with this statement it must be appreciated that apart from theheat produced by the actual compression of the fuel, there is to this added theresidual heat from the engine internals, which in themselves may be below thecritical point, but when added to, or combined with the other, exceed the vitalfigures

A further point that should be considered is that the temperature of the fuelunder compression is related to the actual time taken to compress it, so thatas an example, a high revving engine may well pre-ignite at a certain point andnot do so at lower revolutions.

This explains why in the Start area, or on the line, all may seem well, butonce the power is turned on and the engine speed increased troubles commence.

OCTANE RATINGS

The Octane rating of the fuel in use indicates the detonation sensitivity ofthe fuel and relates directly to the maximum possible compression ratio thatmay be used with that particular fuel.

Again the use of additives will allow that ratio to be a altered.

Naturally every effort must be made to eliminate detonation and on the smallestindication of it taking place, prompt action taken at once to correct theexisting conditions.

With street vehicles it is possible to get the well known audible indicationsof "pinking", but with the competition engine, due to the high noiselevel this may not be so.

Also on multi-cylinder engines you may well have trouble in one or morecylinders, the rest of the engine then masking the trouble, and in fact runningthe faulty cylinders into destruction, the overall noise quite dominating the"pinking" to the point of it being inaudible.

The only real way to check on detonation taking place is by examination of thecylinder head and piston, or what remains of the latter if the trouble has beensevere, which is often the case.

Yet once again you will appreciate how vital it is to make sure you are gettingenough mixture to the engine, the cost of the fuel, even if most of it is blownout of the exhaust system being just so much less than that of mechanicalfailure and the resultant expense putting it right.

While on the matter of getting fuel to the engine we would say withouthesitation that on competitive engines over three litres in capacity, the useof normal carburetors fed by means of float chambers is suspect when using fuelother than petrol, and if supercharged, the capacity figure will be even lower.

FUEL INJECTION

It is for this reason that fuel injection is so popular on large engines usedon special fuels to produce high power outputs, and in the case of the verylarge engines it becomes the only practical way, the use of carburetors beingabortive.

Since in general for competition work you are not too concerned with fueleconomy, the simpler forms of fuel injection are quite satisfactory,eliminating the expensive and elaborate but effective systems of holding theoptimum fuel to air ratio over the operating range of the engine, and ingeneral we see used continuous feed types, such as for example the Hilborn,Enderle, etc.

Power is always difficult to obtain and you cannot take out more than put in,as many have found out, and in fact you cannot get as much in practice, so ifyou propose the use of certain horsepower, you must provide fuel in quantityenough to release the necessary energy to provide that amount of power, aftertaking into consideration the losses in the system of actually converting theenergy from the input form to the output form.

We are now almost at the end of the road. With the information we now have, itonly remains for us to use certain additives to mix with the fuel in order toobtain a mixture that will enable us to extract more power out of existingengines, without stressing them mechanically to destruction.

POWER FUEL ADDITIVES

WE are now at the stage where you have come to the end of what one might termthe usual fuels and enter the area of the additives, that is to say where yoube come part chemist, part engineer, and full-time optimist.

The main object in the use of an additive is to obtain out of the existing fuela further increase in power output at the engine shaft.

Other uses are to alter the tendency of the fuel to pre-ignite and/or detonate,to obtain easier starting, particularly under cold climatic conditions, toreduce running temperature, or as a means of obtaining better mixing of thefuels, that is to say to act as blending agents, not of course all of theseattributes at the same time.

Before we go any further let it be made quite clear that when you commencehandling chemicals, liquids or fuels, call them what you will, it is essentialto maintain a very high standard of cleanliness personally and with regard tocontainers used in the operation, also to mark the contents of each containerwith its known contents
Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #20 on: December 09, 2013, 01:53:10 PM »
since you are now inthe realm of chemical mixing, which under certain conditions could becomedangerous.

ACCURACY PARAMOUNT

Accuracy of measurement is paramount and attention to detail essential, and ifyou are not sure of what you are doing then leave it alone, and in nocircumstances experiment with mixtures of fuels unless you really know what youare doing as the result could be poisonous or explosive, and the explosioncould well occur long before the mixture gets placed in the tank.

Any containers used must be clean internally, and made of a suitable materialto resist the fuel chemically (see the
Basic Fuel Characteristicspage). They should be marked clearly with the nature of the contents, andre-marked when any changes are made.

Many engines have been wrecked due to not marking containers correctly so makethis one of the essential items to be done without fail.

MARK CLEARLY

In general it is safer to obtain fuel, plus any required additives, alreadypre-mixed by the supplier who will do this and mark the container in such amanner there is no doubt at all of the contents, the proportions of the mixturebeing clearly marked.

It also pays to keep a complete and very accurate record of all fuels andmixtures used, together with carburetor or injector system settings, and theresults obtained for future reference, plus, of course, ignition data and typeof plugs and so on.

Having, we hope, given due warning, let us now consider which additives we canuse, taking in turn the basic fuels we have so far discussed and the use ofadditives with them, with the objective use of the additive stated.

In connection with this we have regarded the use of up to 10 percent as anadditive, and over that amount we consider to be a major component of the fuel.

PETROL ADDITIVES

Since almost our major requirement is that of getting more power out of theengine let us see what can be done taking our basic fuels in turn, startingwith Petrol.

Additives are:-

Nitromethane. This increases power, measured at the engine shaft, inproportion to the percentage used, limited by mechanical considerations such ascompression ratio, rate of fuel flow possible in existing system.

If the engine is on the maximum compression ratio usable with petrol, thisratio will have to be dropped by a figure of one ratio if 10 percent additiveused, and by half a ratio if 5 percent additive is decided upon.

With regard to the fuel flow the jet diameter will have to be increased by afigure of 1.125 for use with 10 percent, and in proportion less for the 5percent.

Methanol. The use of Methanol enables a power increase to be obtained bythe simple act of using a higher compression ratio and in fact with 10 percentthe ratio can be increased by 1.5.

That is to say an engine running on 10 to 1 on petrol can now, by the use of 10percent Methanol, run on a ratio of 11.5 to 1 provided, and we stress thispoint, steps are taken to enable the fuel rate of flow to be increased by afigure of 1.125 minimum, or put another way, the jet diameter increased by thatamount on the diameter.

In each case, that is either Nitromethane or Methanol used as an additive, themixture should be premixed and not just supplied to the tank relying on mixingtaking place by accident as it were.

Before we leave petrol it might be pointed out while other additives aresometimes used, they do not as a result of being mixed increase the poweroutput potential of the total fuel.

METHANOL ADDITIVES

We must now consider Methanol as the basic fuel.

To obtain power increase additives are:-

Nitromethane. Bearing in mind we are, as an additive only considering amaximum amount of 10 percent, although we know in fact up to 100 percent can beused as has already been explained, the power increase at the engine shaft willbe in proportion to the amount of additive used, provide' and once again westress this, the fuel flow and jet diameter is increased by 1.125.

The compression ratio will have to be modified, on the maximum for Methanolbefore the additive was introduced and for 10 percent will have to be loweredby a ratio of 1.

Propylene Oxide. This fuel additive in general is safe to handle exceptfor two possible conditions, which under certain circumstances could well bedangerous these are the effects cause by the fuel coming in contact withcopper/alloy containers, fuel tanks, etc., or by rust particles getting in thefuel by accident, for example from a rusty container, or from rust from damagedcan top cap.

To avoid this possibility this fuel is better kept in, and used from, a plasticcontainer of the pure polythene type.

If rust particles are introduced they can do two things. One is to Polymerizeslowly, or put another way, change its chemical state, in this particular caseto form slowly a nasty waxy solid akin to polythene.

The second condition is where the polymerization process takes place quicklydue to external heat on the container, say for example from strong sunlight,which causes the speed up, resulting in a possible explosion.

The remedy is of course obvious so take steps to keep it cool, bearing in mindthe boiling point of this fuel is 93 degrees F. Or as we now tend to regardtemperature, 34 degrees C.

The best increase in power is obtained by some 5 percent as additive, as abovethis figure the gain does not increase in proportion, like the other additives,but in fact tends to decline, so stay at the 5 percent mark.

This fact is known and although reasons can be given for this behavior, at thismoment of time there is a lot of experimental work to be done with thisadditive when used with pure methanol, but anyone carrying out such work mustbe very much out on their own.

NITROMETHANE ADDITIVE

We now come to our last basic fuel, that being Nitromethane, assumed pure, andundiluted, and again our object in using the additive is to obtain a power gainat the engine shaft.

The additive is:-

Propylene Oxide. We have a slight change here in that this can be usedup to a figure of 30 percent rather than our previous 10 percent.


Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #21 on: December 09, 2013, 01:53:43 PM »
Increase in power output will not be proportional to theamount used, but varies from engine to engine, and also with the use of otheradditives with the total fuel, water being a good example.

In general terms one may well expect an increase of some 10 percent at theshaft for the addition of 10 percent additive, but over this figure it isalmost impossible to give an estimate as so many factors will influence theresult.

Due to the oxygen provided by the Nitromethane, the usual air-fuel ratios nolonger hold good and from that fact alone, it is very difficult to state whatthe actual power increase will be.

It has been very clearly stated before that care should be taken when usingNitromethane, but this be-comes even more necessary when dealing with this fuelplus propylene oxide additive.

ANTI PRE-IGNITIONADDITIVES

WE now come to the use of additives for reasons other than power increase. Inthis chapter we will deal only with additives that can be of assistance to usin connection with Pre-ignition and the other problem of Detonation.

We again go through our three basic fuels in the same order.

WHEN USING PETROL . . .

We have three additives in Methanol, Acetone and Benzole (Benzene) and all ofthem are introduced with the main object of reducing Detonation by increasingin effect the Octane rating of the total fuel. Pre-ignition in general shouldnot present a problem when using as basic fuel petrol.

Methanol in Petrol. This is the best from the point of view of reducingDetonation, followed by Acetone and then Benzole in that order.

Methanol can be added in all proportions up to 100 percent, but as an additivelimited to 10 percent will give an Octane increase of about 5 points. Forexample 98 Octane can be increased to 103, or looking at it another way, cheapfuel of say 91 Octane can, by the use of 10 percent Methanol, or approximatelythree quarters of a pint per gallon, will produce fuel of 96 Octane.

Acetone in Petrol. Can be used up to 100 percent but with the nominal 10percent will give an increase of 3 points rather than 5.

The major difference from Methanol being that due to the higher calorific valueof Acetone, the consumption does not increase so much, but still provides ahigher octane rating.

Benzole (Benzene) in Petrol. Again can be used up to 100 percent butwith the 10 percent amount will provide in points a rise of 2.

In many cases this additive is used to counteract detonation since some 10percent will, in certain cases, provide enough rise in octane rating to do justthat.

WHEN USING METHANOL .

Now we come to Methanol as the main fuel, and as additives to reducePreignition and/or Detonation we have two.

Acetone in Methanol. Here we are concerned only with Pre-ignition sinceMethanol has itself a very high octane rating, and is therefore to be regardedas almost free from detonation problems.

Once again our figure of 10 percent is the most advantageous use of theadditive, as over that figure has a declining effect in proportion to theamount used.

The effect of using this additive is to move the auto-ignition point upwards,and this was fully explained as will be remembered.

Water in Methanol. Up to 5 percent or a maximum of 10 percent with theobject of increasing the octane rating even higher, to reduce detonation undervery high supercharge conditions.

WHEN USING NITROMETHANE


Last of all now we have Nitromethane as our main fuel. Here we have threeadditives to help with preignition and or detonation.

Methanol in Nitromethane. Since Nitromethane has itself a tendency topre-ignite and detonate, the sole object of up to 10 percent Methanol as anadditive is to reduce this tendency to detonate while having only a minoreffect on pre-ignition.

Water in Nitromethane. Up to a maximum of 2.5 percent as this is themaximum amount that will mix without separation taking place. It reduces bothpreignition and detonation due to the internal cooling effect alone.

In practice a combination of Methanol and Water is the better use of the twoadditives, the proportions being 2.5 percent water and 7.5 percent Methanolgiving a good safe usable blend of Nitromethane, with almost the full powercapability of undiluted Nitromethane.

Acetone in Nitromethane. Up to a maximum of 5 percent. This reducespreignition by raising the auto-ignition point and any small decrease indetonation is incidental.

EASIER STARTING ADDITIVES


WE now come to the last use of additives and that is to assist with starting,which should not be a problem but nevertheless sometimes is. Again we deal withour three basic fuels as before.

WHEN USING PETROL . . .

Acetone is the only safe additive to use, its function being that itincreases the volatility of the mixture, without reducing the basic fuelproperties too much. Up to 5 percent being quite enough to use.

Ether is the only other additive to use with Petrol and may be used inthe same manner as Acetone and for the same reason, but is in fact notrecommended for use with spark ignition systems, and has obvious handlingproblems.

It can also quite easily produce a wrecked engine, so use it if you must, butyou have been warned

WHEN USING METHANOL .

Acetone is the only additive and up to 10 percent maximum. The action ofthis is to increase the volatility of the total fuel or put another way itreduces the flash point temperature.

Main use is on very cold days, but in fact it even then should not be reallynecessary, however let us say it is convenient.

Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #22 on: December 09, 2013, 01:56:20 PM »

WHEN USING NITROMETHANE

When our main fuel is Nitromethane, the only additive is again Acetone for thesame reasons as when used with Methanol.

All fuels have one common blending agent, this being Acetone, but in most caseswill mix satisfactorily without, but where found necessary, the amount usedshould be the minimum required to obtain complete mixing without trace ofseparation, visually checked.

In some cases it may be necessary to use quite high percentages, for examplesome 30 percent when blending Benzole and Methanol.

Over recent years the methods used in producing petrol have changed and withthe modern petrol's better blending is obtained with Methanol due to therefining techniques now used without a blending agent being used.

STALE FUELS

Many think that fuels when stored become less effective with age, but in factthis is not so provided the cans or containers are fitted with caps or snap onlids that fit correctly.

Two fuels that are difficult to keep unless great care is taken in sealing thecontainers are Ether and Propylene Oxide, the high rate of evaporation beingthe problem.

In conclusion, may we just repeat three major things to keep in mind.

· First of all apart from Petrol, always tend to keep the mixture on the richside and never on the weak.

· In all cases never rush, take your time and be quite accurate in yourmeasurements.

· Last of all do not experiment unless you know what you are doing as it couldbe both expensive and dangerous.

GOOD RACING!

BASIC FUEL CHARACTERISTICS
[TABLE=class: MsoNormalTable, width: 5]
[TR]
 [TD=width: 229, bgcolor: transparent]  
GENERAL  DESCRIPTION
 METHANOL (Methyl Alcohol)  CH30H is a volatile, highly inflammable, water-clear liquid with a mildly  spirituous odour. Miscible with water or nitromethane in all proportions and  almost all with petrol.
 [/TD]
 [TD=width: 252, bgcolor: transparent]  
BASIC  CHARACTERISTICS
 [TABLE=class: MsoNormalTable, width: 100%]
  [TR]
   [TD=width: 20%, bgcolor: transparent]    
Flash Point
   [/TD]
   [TD=width: 21%, bgcolor: transparent]    
Boiling Point
   [/TD]
   [TD=width: 19%, bgcolor: transparent]    
Freezing    Point
   [/TD]
   [TD=width: 12%, bgcolor: transparent]    
Specific    Gravity
   [/TD]
   [TD=bgcolor: transparent]    
Lbs/Gall approx
   [/TD]
  [/TR]
  [TR]
   [TD=width: 20%, bgcolor: transparent]    
F C
   [/TD]
   [TD=width: 21%, bgcolor: transparent]    
F C
   [/TD]
   [TD=width: 19%, bgcolor: transparent]    
F C
   [/TD]
   [TD=width: 12%, bgcolor: transparent]    
   [/TD]
   [TD=bgcolor: transparent]    
   [/TD]
  [/TR]
 [/TABLE]
   61 16  148 64 -144 -97  0.796    8[/TD]
 [/TR]
 [TR]
  [TD=width: 229, bgcolor: transparent]  NITROMETHANE CH3NO2
  is an inflammable water-clear liquid with a mild odour, containing  approximately 53% by weight of oxygen. Water will mix with nitromethane to  the extent of 2.5% only, by volume.
  [/TD]
  [TD=width: 252, bgcolor: transparent] 110 43  214 101 -20 -29   1.13  11.25[/TD]
 [/TR]
 [TR]
  [TD=width: 229, bgcolor: transparent]  ACETONE (Dimethyl  Ketone) CH3COCH3
  is a highly volatile, highly inflammable, water-clear liquid with a strong,  sharp, characteristic odour. Miscible with all the chemicals listed here, and  water.
  [/TD]
  [TD=width: 252, bgcolor: transparent] 0 -18   133 56  -138 -94  0.791   8[/TD]
 [/TR]
 [TR]
  [TD=width: 229, bgcolor: transparent]  ETHER  (Diethyl Ether) C2H5OC2H5
  is an extremely volatile, highly inflammable, water clear liquid with a  strong, lingering, characteristic odour. Miscible with all the chemicals  listed here but not with water.
  [/TD]
  [TD=width: 252, bgcolor: transparent]-40 -40  95 35   -183 -116  0.714   7[/TD]
 [/TR]
 [TR]
  [TD=width: 229, bgcolor: transparent]  BENZOLE,  (Benzene) C6H6
  is an inflammable water-clear liquid with a dull sweet odour Miscible in most  proportions with all the chemicals listed here but not with water.
  [/TD]
  [TD=width: 252, bgcolor: transparent] 12 -11  176 80   41  5    0.879 8.75[/TD]
 [/TR]
 [TR]
  [TD=width: 229, bgcolor: transparent]  NITROBENZENE C6H5NO2
  is an inflammable, yellow, oily liquid with a strong odour of almonds.  Miscible in most proportions with all the chemicals listed here but nrot with  water.
  [/TD]
  [TD=width: 252, bgcolor: transparent] 190 88  412 211  41  5    1.20    12[/TD]
 [/TR]
 [TR]
  [TD=width: 229, bgcolor: transparent]  PROPYLENE OXIDE (1 :2. Epoxypropane) CH3-CH-CH2
  is an extremely volatile, very reactive, highly inflammable, water-clear  liquid with a light gaseous odour. Miscible with all the chemicals listed  here but only partially with water.
  [/TD]
  [TD=width: 252, bgcolor: transparent] 32  0   93 34  -155 -104  0.83   8.25[/TD]
 [/TR]
 [TR]
  [TD=width: 229, bgcolor: transparent]  UCON LB625  (Polyalkalene glycol)
  A water-clear synthetic lubricating oil with exceptionally high film strength  properties. Miscible with all the chemicals listed here but not with water.
  [/TD]
  [TD=width: 252, bgcolor: transparent] 430 221 -  -   -25 - 32    1.0    10[/TD]
 [/TR]
[/TABLE]
 
[/COLOR][/SIZE]
Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #23 on: December 09, 2013, 01:57:33 PM »

[TABLE=class: MsoNormalTable, width: 461]
[TR]
 [TD=width: 10%, bgcolor: transparent]  
 
 [/TD]
 [TD=width: 48%, bgcolor: transparent]  [TABLE=class: MsoNormalTable, width: 100%]
  [TR]
   [TD=width: 25%, bgcolor: transparent]    
Conservative Maxium Compression Ratio
   [/TD]
   [TD=width: 25%, bgcolor: transparent]    
Air/Fuel Ratio for Max Power lbs/lbs
   [/TD]
   [TD=width: 25%, bgcolor: transparent]    
Energy from Combustion B.T.U/lb
   [/TD]
   [TD=width: 25%, bgcolor: transparent]    
Coolling Effect (Latent heat of Vaporisation)    B.T.U./lb
   [/TD]
  [/TR]
 [/TABLE]
 
 [/TD]
 [TD=width: 42%, bgcolor: transparent]  
Use in Internal  Combustion Engines
 [/TD]
[/TR]
[TR]
 [TD=width: 10%, bgcolor: transparent]  
Methanol
 [/TD]
 [TD=width: 48%, bgcolor: transparent]17 : 1       4.5 : 1     9770         472[/TD]
 [TD=width: 42%, bgcolor: transparent]  Methanol permits the use of very high  compression ratios when unsupercharged or high boost pressures when  supercharged. The large cooling effect increases volumetric efficiency and is  of particular use in the supercharged engine reducing charge temperature  after compression. A tendency to pre-ignition is most noticeable at weak  mixture levels.
 [/TD]
[/TR]
[TR]
  [TD=width: 10%, bgcolor: transparent]  Nitromethane
 [/TD]
 [TD=width: 48%, bgcolor: transparent]  [TABLE=class: MsoNormalTable, width: 100%]
  [TR]
   [TD=width: 25%, bgcolor: transparent]    
6.5 : 1
   
(10 : 1 with    rich mixtures)
   [/TD]
   [TD=width: 25%, bgcolor: transparent]    
2.5 : 1 to 0.5:1    at least
   [/TD]
   [TD=width: 25%, bgcolor: transparent]    
5000
   [/TD]
   [TD=width: 25%, bgcolor: transparent]    
258
   [/TD]
  [/TR]
 [/TABLE]
 
 [/TD]
 [TD=width: 42%, bgcolor: transparent]  Nitromethane enables considerable power  increases to be obtained (70 percent minimum with proper use). Most often  used blended with methanol, in various propor ,tions to provide power  increases consistent with engine strength, etc. A tendency to detonation is  reduced by an increase in mixture strength, reduction in engine temperature,  reduction in compression ratio or the addition of methanol.
 [/TD]
[/TR]
[TR]
  [TD=width: 10%, bgcolor: transparent]  
Acetone
 [/TD]
 [TD=width: 48%, bgcolor: transparent]   17 : 1     9.4 : 1    12,500        225   approx[/TD]
 [TD=width: 42%, bgcolor: transparent]  As a basic fuel acetone appears to have  all the required characteristics, these in general Iying midway between  methanol and petroleum. An exception is its very high anti-knock rating which  approaches that of methanol. Other uses are as an additive to other fuels,  notably to methanol to reduce pre-ignition sensitivity and promote easier  starting under low temperature conditions, up to 10 percent for this purpose.
 [/TD]
[/TR]
[TR]
  [TD=width: 10%, bgcolor: transparent]  
Ether
 [/TD]
 [TD=width: 48%, bgcolor: transparent]   4 : 1      9.8 : 1    15,000        153[/TD]
 [TD=width: 42%, bgcolor: transparent]  Not used as a basic fuel in spark  ignition engines due to its very low knock-rating, but this characteristic is  desirable in the small high-speed diesel engine where it is used in  relatively large percentages (approx. 15 percent to 35 percent by volume) as  an additive. Its volatile nature and low flash point make it useful as an  additive tuP to 5 percent) to improve starting and give a rapid throttle  response.
 [/TD]
[/TR]
[/TABLE]
Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rsss396

Everything you ever wanted to know about racing fuel
« Reply #24 on: December 09, 2013, 01:58:25 PM »
[TABLE=class: MsoNormalTable, width: 461]
[TR]
 [TD=width: 10%, bgcolor: transparent]  
Benzole
 [/TD]
 [TD=width: 48%, bgcolor: transparent]  15 : 1     10.8 : 1    17,300        153[/TD]
 [TD=width: 42%, bgcolor: transparent]  Most often used blended with methanol to  give a greater energy per unit volume with reduction in the latent heat  vapourisation, this being a compromise often used for long distance racing  where fuels other than petrol are allowed.
 [/TD]
[/TR]
[TR]
  [TD=width: 10%, bgcolor: transparent]  
Nitrobenzene
 [/TD]
 [TD=width: 48%, bgcolor: transparent] not known   8 : 1       10,800        143[/TD]
 [TD=width: 42%, bgcolor: transparent]  Blended in very small proportions with  other fuels it is thought to act as an ignition accelerator. As this material  has a strong odour even after combustion it is sometimes used as an additive  in other fuels (approx. 0.5 percent) to mask the normal exhaust odour making  it difficult to detect the base fuel type.
 [/TD]
[/TR]
[TR]
  [TD=width: 10%, bgcolor: transparent]  
Propylene Oxide
 [/TD]
 [TD=width: 48%, bgcolor: transparent] not known   9.6 : 1     14,000        220[/TD]
 [TD=width: 42%, bgcolor: transparent]  Used as an ignition accelerator additive  particularly with nitromethane (up to 20 percent by volume with pure  nitromethane) where noticeable increases in power are possible. Easier  starting and smoother running are other benefits when blended with most other  fuels (up to 5 percent)
 [/TD]
[/TR]
[TR]
  [TD=width: 10%, bgcolor: transparent]  
Ucon
 [/TD]
 [TD=width: 48%, bgcolor: transparent]  At 0 F this oil compares to SAE 20 at the  same temperature, and at 210 F it compares to SAE 50 at the same temperature
 [/TD]
 [TD=width: 42%, bgcolor: transparent]  Used to advantage in all two stroke  engines operating on fuel/oil mixtures. The unusually high him strength  properties allowing a reduction in the amount of oil in the fuel by as much  as 55 percent. Of particular use in very small high speed two stroke engines  where the normal oil content can be up to 30 percent of the total volume, with  the attendant restriction on the amount oF fuel that can be burnt.
 [/TD]
[/TR]
[/TABLE]

Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

 

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