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02-24-2008, 09:14 PM | #51 |
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Re: Head differences
That might explain why I still have a ticking noise. I had my driver's side head replaced in october for a ticking noise ( old head was painted blue) and I still have a noise. The noise seems to be slightly different, but I am not sure. I know the noise is only there when the car is hot and I can only hear it at idle. What would be the correct fix and would there be any long term damage if it wasn't fixed?
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02-24-2008, 10:08 PM | #52 | |
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Re: Head differences
Quote:
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02-25-2008, 01:18 AM | #53 |
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Re: Head differences
Honestly i have this same problem, the "ticking" doesn't bother me much, but i am curious as to the long term side effects. If there are none i wouldn't bother leaving my car at ford for a week and not having a vehicle.
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02-29-2008, 05:32 AM | #54 |
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Re: Head differences
If it was piston noise why is it only on the drivers side left rear corner. Piston slap can be heard when it's cold not when it's fully warmed up like both of mine did. Piston slap was from when cold and the piston was at the bottom of the stroke. Because the piston is smaller at the top around the rings the skirt was hanging out the bottom of the cyl the biggest part of the piston. Beside piston noise gets worst fast.
Is it a block problem for it too be only the left rear corner I think not. Poeple with high boost would been having lots of block problems. |
03-07-2008, 08:03 PM | #55 |
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Re: Head differences
Going back to the number of thread on the heads, has anyone had a plug blow out of a 4 thread head? I know it was a problem with the Lightnings.
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04-24-2008, 07:56 PM | #56 |
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Re: Head differences
I'm in the market to buy a used Mach and want to ensure I don't get screwed buying a car with bad heads, piston skirts, or whatever. Let me ask these questions then, after ensuring I have this all correct -- someone correct me if I'm wrong here:
Based on what DanB has stated and repeated for our benefit, there should be no problems at all with the "9 thread heads" due to their cooling redesign, which avoids overheating and associated galled valve guides. But how does resolution of the guide issue resolve the tick caused by the piston skirt? Or is the collapsed piston skirt also caused by the overheating of the head? Is there any evidence anywhere that "9 thread headed" engines have the tick? I would assume NOT but can someone answer that? From what DanB says, the "4 thread heads" can overheat and develop galled valve guides. This includes the blue strip heads too, since they're identical to the non-blue-strip head. CBRRIDER98 says he had a tick even with blue heads so what DanB says makes sense, since that's evidence that blue strip heads, being the same design as the originals, still have the overheating problem. What I'm not clear on here is whether the galled valve guides and the collapsed piston skirt are two issues related to one another merely because of a 3rd issue (overheating) or if the valve guide issue somehow allows you to hear the piston skirt issue. It just doesn't make much sense that compression in Jerome's cylinder was the same before and after the head job, yet the noise was resolved. Could he have had only a valve guide issue, and not a separate piston skirt issue then? Seems to me the piston slap noise would be twice as fast as the valve noise, wouldn't it? The piston is moving on BOTH the intake and exhaust stroke, but the valve only moves when opening/closing on whatever stroke the piston is on. Couldn't the source of the noise be proved somehow using engine rpm and counting the # of ticks in a given time? rob Last edited by 84GT Ragtop; 04-29-2008 at 11:36 AM. |
06-25-2008, 08:56 PM | #57 |
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Re: Head differences
So does ford not have some sort of a recall out on the head tick problem? also does anybody know the long term effects of it?
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06-26-2008, 05:11 AM | #58 |
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Re: Head differences
I can't figure why there is such a fuss about these heads. I drive my car to have fun, and have had no issues with the heads. My car was built in April 2003, leaving me with the 4 thread head. The car makes great power, and is a fast car. No problems. This thread seems to create paranoia about the heads. All ya all just need to drive, race, and not worry or spend the money to fix something that is not broke! This thread is nonsense in lieu of the sanity of people who are fixated on a problem that doesn't exist if you are smart about your driving and car maintenance. Forget what head you have and enjoy your car. Quit obsessing!
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06-26-2008, 07:28 AM | #59 |
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Re: Head differences
I worked for Ford putting myself through school back in the mid 60's and early 70's (7 years bending wrench and all the Ford schools that where available at the time). Ford had a ton of problems with the 428 cobrajet related to value guide problems. Back then we did not replace the heads, instead we re-worked the value guidels. I mean hundreds of them - what a pain!!!
If you think you have a guide problem it is easy to check. Remove the value cover and with a larger flat blade screw driver see if you can rock the value in it's seat back and forth. Position the screw driver shaft on the value spring retainer and the blade on the head. If you get movement that you can really see, you have a value guide problem. Perhaps I am old school but if you have piston slap due to either piston, ring or bore problems normally you will experience a loss of compression during a compression check. Although it can be somewhat small, it will be there. As a rule, you will also experience oil fouling on the plug(s) where the piston is loose in the bore. Just an ole timers view .....
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06-26-2008, 07:45 AM | #60 |
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Re: Head differences
You will hear a lot more then just a tick !!! How about a heavy rattle - Or at least that has been my experience. I have been building cars, racing, and blowing things up for over 40 years which includes a number of pro-stock cars in my earlier years....
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10-10-2008, 08:47 PM | #61 |
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Re: Head differences
Bringing this to the top. Dans post is very informative and all new owners need to read it.
http://www.mach1registry.org/forums/...8&postcount=10
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10-13-2008, 01:01 PM | #62 | |
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Re: Head differences
Quote:
That is because that is where the coolant has no out let therefore there is more heat on cylinder 7&8 allowing for more detonation in those cylinders. You see when you have heat you can have a lot of timing or you are destine for disaster
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10-13-2008, 01:15 PM | #63 | |
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Re: Head differences
Quote:
You are correct to some degree. You see the piston skirts are so small and the blocks are so soft that it does not take much to oval the cylinder with this combination it does not take much to causes the piston to rock back and forth. The amount of cylinder pressure will stabilize the piston enough to deaden the noise to some degree however as the problem gets worse the noise becomes more pronounced. Also most people can’t tell the deference between a Tick (rocker or lifter noise and piston slap) that is the reason why ford is getting away with a .005 thou mill on the head that bumps the combustion pressure thus stabilizing the piston some what enough to have the customer go away. As for work experience I highly doubt there was a cause to post that.
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10-13-2008, 07:02 PM | #64 |
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Re: Head differences
A couple of things. I just purchased an 04 mach1 TR with only 3,500 miles on it. Whoo Hoo! OK Now that that this is over with let me voice in. I have been building engines for a very long time. I have also had some very ferocioulsy fast cars as well. This is what I know. I have an 04' with a build date of 10/07 second shift. My cylinder heads have no blue paint on them and also have 8 thread spark plug holes. That kind of adds a twist to some of the earlier posts claiming that I should have a blue painted cylinder head and that the 8 thread design didn't start until until 11/15. Ok no big deal here because weird things happen during manufacturing all the time. As for the noise...........This is also what I know. Most of your posts are all right. Mis-detonation and heat will cause pistons to do some very strange things like scoring, marring, cracking, breaking etc. As for us having soft blocks.......that shouldn't matter much as our cylinders are sleeved due to the aluminum blocks. There should be no issues there. A piston slap usually only occurs when the engine is cold and this is fact. I do admit that I do not understand the water circuit diagrams of our engines and how the water flows, as I just haven't had the darn thing long enough to understand it. Heat will also do some strange things to valve guides. The ticking noise many of us hear usually calms down for the most part as our engines cool down (idling for about 2 or so minutes) so the heat theory seams to hold some water. As for how detrimental it is to our engines........that is another story. The tick most of us hear isn't much more loud than the normal noise from our injectors. This isn't too alarming as our engines are made entirely of aluminum and that stuff really conducts sound, much more so than iron. The tick could be caused by a number of more issues. For any of us old timers (not that old really, under 40) I remember a TSB Ford had out in the day for the #5 cylinder lifters in the 5.0's (1991 or so) would tick if operated with synthetic motor oil. That certainly didn't stop anyone from using sythetic oil and certainly didn't stop any of us from beating the tar out of those cars. Oil does strange things when it's heated too. It gets very thin. Thin enough to where lifters will not pump up as much as they should due to blead off. Since the tick I hear isn't present when the motor is cold and calms down quite a bit if I let the engine idle for a few minutes before shut down, I believe it to be a oil thinning issue. I may be wrong, and have been wrong before but this would also agree with the heat issue just not related to the engine coolant but rather the engine oil. Two of my friends also have Mach 1's and to be honest they also have a very slight tick when hot and more noticable right before shut down but again if alllowed to idle for a bit this too seems to settle the noise down. I also own an 08' GT/CS and this engine also experiences a more noisy vlave train when the engine is hot and even more noticable if pulled into the garage after a hard running and not permitted to cool down further before shut down. It would be great if we could get our hands on the oil circuit diagrams as well as coolant circuit diagrams. I am sure they exist somewhere. That is my .02 worth and I am sticking to it. BTW - this board has some very passionate members and I hope I will be able to strengthen the community. I am glad to be here and more importantly I am glad to be a proud owner of these fine cars.
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10-13-2008, 07:23 PM | #65 |
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Re: Head differences
I love this debate. I hope we can keep it constructive.
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10-13-2008, 07:31 PM | #66 |
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Re: Head differences
Oh and one more thing to mention for the oil story......the noise goes away when the RPMS pick up = more oil volume to keep lifters from collapsing. This will be fun and to be honest with all of the barin power here, we will figure it out.
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10-13-2008, 07:41 PM | #67 |
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Re: Head differences
WOW, Im just glad my motor dosn't make any ticking noises, I got 03 heads with the blue stripe. Guess for now Im just lucky....
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10-13-2008, 07:59 PM | #68 | |
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Re: Head differences
Quote:
I also agree with the above post about oil .I was using Motorcraft 5/20 Full Syn.for quite a while. Earlier this year I changed the oil after the winter and could only find Castrol 5/20 Blend . I changed the oil using that and posted how much less noise was present .This is still true and noted alot less when the motor is hot and idling .I think the Full Syn .oils thin out too much too. When I first used Full Syn Oil in my old 5.0..it used it alot more because the Forged pistons had more cylinder wall clearance .I went back to just Reg Castrol and this issue lessened back then .I know not a 4.6 just noted. I think that is it also worth saying that a Coolant addative like Water Wetter will also be helpful try to even out the cooling heat transfer in the motor too.
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10-14-2008, 11:40 AM | #69 | ||||||||||
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Re: Head differences
So what you are telling me is that a cylinder produces no more compression off of idle than it does during idle??? Also the reason you don’t have the blue stipe is because you your self just stated that you have an 2004 motor so why would you have a 2003 head with a blue strip
Quote:
the reason you don’t have the blue stipe is because you your self just stated that you have an 2004 motor so why would you have a 2003 head with a blue strip. You wouldn’t you actually have the updated FR500 head as do all 2004 producer AFTER 11/03 Quote:
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The info that I share on this site is not BS. I work on these cars everyday and have done so for many years. We are here to help and if you need some more information please feel free to contact us and we will tell you what we know and how we received the information that we have. Have a nice day and congratulations on your new car I hope you stay here for a long time to come
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10-15-2008, 01:27 AM | #70 |
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Re: Head differences
Well I certainly did not mean to offend you. You certainly seem defensive. Cylinder pressure is cylinder pressure regardless if it is OHV or OHC. No debating that. I do not believe ductile Iron (the material used for our cylinder sleeves) to be soft. True there are better materials but soft it is not but that term is also relative as it is much softer than diamonds. I understand OHC very well. We can talk stoichiometry all day long. No issues here. I have 25 years of engine building experience and one thing I have learned is that if you talk to 100 people you generally get 100 different answers and everyone has a better mouse trap. True I am sure you build very reliable engines as do I. I would never take that away from anyone at least until I have seen their work.....A little humor there. I give everyone the benefit of the doubt. We will have to agree to disagree. BTW that was a typo on my build date it should have been 10/04/03 and not 10/07. I have done lots of work on mod motors and haven't had any blow up...........yet. More humor there. The fact is there are tons of theories out there. The fact is I have never heard a piston slap when hot and not when it is cold. It has always been the reverse. I have heard plenty of lifters make some noise when the oil changes viscosity under extreme heat as the lifters bleed off too qickly, both in OHC and OHV. All hydraulic lifters require oil pressure to remain pumped up. I have no idea what your experience is as I am sure it must be extensive as is mine. What does concern me is that I merely approached this post wanting to add some additional ideas and never once said you were wrong, incorrect, or tried to tear you down and you immediately went on the defensive and did your best to point out that I am wrong. Most professionals are willing to listen to other points of view and hear other ideas as this is the only way we all truly grow our knowledge base. I am sorry for offending you and to be honest I am also sorry that you are so unwilling to hear other points of view. And anytime you wish to discuss stoichiometry, fluid dynamics, or any other engine theory I am all ears as I would like to increase my knowledge base.
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10-15-2008, 01:47 AM | #71 | |
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Re: Head differences
Quote:
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10-18-2008, 12:43 AM | #72 |
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Re: Head differences
What about 99/01 Cobra heads??
How much different are they than the newer DOHC?
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10-18-2008, 12:59 AM | #73 | |
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Re: Head differences
Quote:
stoichiometry ?
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10-18-2008, 01:02 AM | #74 |
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Re: Head differences
I Found it!! It totally Makes Sense!!! Definition
Stoichiometry rests upon the law of conservation of mass, the law of definite proportions (i.e., the law of constant composition) and the law of multiple proportions. In general, chemical reactions combine in definite ratios of chemicals. Since chemical reactions can neither create nor destroy matter, nor transmute one element into another, the amount of each element must be the same throughout the overall reaction. For example, the amount of element X on the reactant side must equal the amount of element X on the product side. Stoichiometry is often used to balance chemical equations. For example, the two diatomic gases, hydrogen and oxygen, can combine to form a liquid, water, in an exothermic reaction, as described by the following equation: The term stoichiometry is also often used for the molar proportions of elements in stoichiometric compounds. For example, the stoichiometry of hydrogen and oxygen in H2O is 2:1. In stoichiometric compounds, the molar proportions are whole numbers (that is what the law of definite proportions is about). Compounds for which the molar proportions are not whole numbers are called non-stoichiometric compounds. Stoichiometry is not only used to balance chemical equations but also used in conversions, i.e., converting from grams to moles, or from grams to milliliters. For example, to find the number of moles in 2.00 g of NaCl, one would do the following: In the above example, when written out in fraction form, the units of grams form a multiplicative identity, which is equivalent to one (g/g=1), with the resulting amount of moles (the unit that was needed), is shown in the following equation, Stoichiometry is also used to find the right amount of reactants to use in a chemical reaction. An example is shown below using the thermite reaction, So, to completely react with 85.0 grams of iron (III) oxide, 28.7 grams of aluminum are needed. [edit] Different stoichiometries in competing reactions Often, more than one reaction is possible given the same starting materials. The reactions may differ in their stoichiometry. For example, the methylation of benzene (C6H6) may produce singly-methylated (C6H5CH3), doubly-methylated (C6H4(CH3)2), or still more highly-methylated (C6H6 − n(CH3)n) products, as shown in the following example, In this example, which reaction takes place is controlled in part by the relative concentrations of the reactants. [edit] Stoichiometric coefficient The stoichiometric coefficient in a chemical reaction system of the i–th component is defined as or where Ni is the number of molecules of i, and ξ is the progress variable or extent of reaction (Prigogine & Defay, p. 18; Prigogine, pp. 4–7; Guggenheim, p. 37 & 62). The extent of reaction can be regarded as a real (or hypothetical) product, one molecule of which is produced each time the reaction event occurs. The stoichiometric coefficient νi represents the degree to which a chemical species participates in a reaction. The convention is to assign negative coefficients to reactants (which are consumed) and positive ones to products. However, any reaction may be viewed as "going" in the reverse direction, and all the coefficients then change sign (as does the free energy). Whether a reaction actually will go in the arbitrarily-selected forward direction or not depends on the amounts of the substances present at any given time, which determines the kinetics and thermodynamics, i.e., whether equilibrium lies to the right or the left. If one contemplates actual reaction mechanisms, stoichiometric coefficients will always be integers, since elementary reactions always involve whole molecules. If one uses a composite representation of an "overall" reaction, some may be rational fractions. There are often chemical species present that do not participate in a reaction; their stoichiometric coefficients are therefore zero. Any chemical species that is regenerated, such as a catalyst, also has a stoichiometric coefficient of zero. The simplest possible case is an isomerism in which νB = 1 since one molecule of B is produced each time the reaction occurs, while νA = −1 since one molecule of A is necessarily consumed. In any chemical reaction, not only is the total mass conserved, but also the numbers of atoms of each kind are conserved, and this imposes a corresponding number of constraints on possible values for the stoichiometric coefficients. Of course, only a small subset of the possible atomic rearrangements will occur. There are usually multiple reactions proceeding simultaneously in any natural reaction system, including those in biology. Since any chemical component can participate in several reactions simultaneously, the stoichiometric coefficient of the i–th component in the k–th reaction is defined as so that the total (differential) change in the amount of the i–th component is . Extents of reaction provide the clearest and most explicit way of representing compositional change, although they are not yet widely used. With complex reaction systems, it is often useful to consider both the representation of a reaction system in terms of the amounts of the chemicals present { Ni } (state variables), and the representation in terms of the actual compositional degrees of freedom, as expressed by the extents of reaction { ξk }. The transformation from a vector expressing the extents to a vector expressing the amounts uses a rectangular matrix whose elements are the stoichiometric coefficients [ νi k ]. The maximum and minimum for any ξk occur whenever the first of the reactants is depleted for the forward reaction; or the first of the "products" is depleted if the reaction as viewed as being pushed in the reverse direction. This is a purely kinematic restriction on the reaction simplex, a hyperplane in composition space, or N‑space, whose dimensionality equals the number of linearly-independent chemical reactions. This is necessarily less than the number of chemical components, since each reaction manifests a relation between at least two chemicals. The accessible region of the hyperplane depends on the amounts of each chemical species actually present, a contingent fact. Different such amounts can even generate different hyperplanes, all of which share the same algebraic stoichiometry. In accord with the principles of chemical kinetics and thermodynamic equilibrium, every chemical reaction is reversible, at least to some degree, so that each equilibrium point must be an interior point of the simplex. As a consequence, extrema for the ξ's will not occur unless an experimental system is prepared with zero initial amounts of some products. The number of physically-independent reactions can be even greater than the number of chemical components, and depends on the various reaction mechanisms. For example, there may be two (or more) reaction paths for the isomerism above. The reaction may occur by itself, but faster and with different intermediates, in the presence of a catalyst. The (dimensionless) "units" may be taken to be molecules or moles. Moles are most commonly used, but it is more suggestive to picture incremental chemical reactions in terms of molecules. The N's and ξ's are reduced to molar units by dividing by Avogadro's number. While dimensional mass units may be used, the comments about integers are then no longer applicable. [edit] Stoichiometry matrix In complex reactions, stoichiometries are often represented in a more compact form called the stoichiometry matrix. The stoichiometry matrix is denoted by the symbol, . If a reaction network has n reactions and m participating molecular species then the stoichiometry matrix will have corresponding n columns and m rows. For example, consider the system of reactions shown below: S1 → S2 5S3 + S2 → 4S3 + 2S2 S3 → S4 S4 → S5 This systems comprises four reactions and five different molecular species. The stoichiometry matrix for this system can be written as: where the rows correspond to S1, S2, S3, S4 and S5, respectively. Note that the process of converting a reaction scheme into a stoichiometry matrix can be a lossy transformation, for example, the stoichiometries in the second reaction simplify when included in the matrix. This means that it is not always possible to recover the original reaction scheme from a stoichiometry matrix. Often the stoichiometry matrix is combined with the rate vector, v to form a compact equation describing the rates of change of the molecular species: [edit] Gas stoichiometry Gas stoichiometry is the quantitative relationship between reactants and products in a chemical reaction when it is employed for reactions that produce gases. Gas stoichiometry applies when the gases produced are assumed to be ideal, and the temperature, pressure, and volume of the gases are all known. Often, but not always, the standard temperature and pressure (STP) are taken as 0°C and 1 bar and used as the conditions for gas stoichiometric calculations. Gas stoichiometry calculations solve for the unknown volume or mass of a gaseous product or reactant. For example, if we wanted to calculate the volume of gaseous NO2 produced from the combustion of 100 g of NH3, by the reaction: 4NH3 (g) + 7O2 (g) → 4NO2 (g) + 6H2O (l) we would carry out the following calculations: There is a 1:1 molar ratio of NH3 to NO2 in the above balanced combustion reaction, so 5.871 mol of NO2 will be formed. We will employ the ideal gas law to solve for the volume at 0 °C (273.15 K) and 1 atmosphere using the gas law constant of R = 0.08206 L · atm · K-1 · mol-1 : PV = nRT V Gas stoichiometry often involves having to know the molar mass of a gas, given the density of that gas. The ideal gas law can be re-arranged to obtain a relation between the density and the molar mass of an ideal gas: and and thus: where: P = absolute gas pressure V = gas volume n = number of moles R = universal ideal gas law constant T = absolute gas temperature ρ = gas density at T and P m = mass of gas M = molar mass of gas [edit] Stoichiometric air-fuel ratios of common fuels Fuel By weight By volume [1] Percent fuel by weight Gasoline 14.7 : 1 - 6.8% Natural Gas 17.2 : 1 9.7 : 1 5.8% Propane (LP) 15.5 : 1 23.9 : 1 6.45% Ethanol 9 : 1 - 11.1% Methanol 6.4 : 1 - 15.6% Hydrogen 34 : 1 2.39 : 1 2.9% Diesel 14.6 : 1 - 6.8% [edit] Methods to solving stoichiometry problems To use the following methods, you must first determine the molar mass of the reagents and the products, and balance the reaction. Using the known masses of compounds in the reaction, calculate the number of moles there are of each known. Then determine which chemical is the limiting reagent. One method has been commonly taught in various text books. Like equivalent weight, it is the amount of an element that reacts, or is involved in reaction with, 1 mole of electrons. When choosing primary standards in analytical chemistry, compounds with higher "equivalent weights" are, in general, more desirable because weighing errors are reduced or minimized. For example, hydrogen, with atomic weight 1.008 and valence of 1, has an equivalent weight of 1.008. Oxygen assumes a valence of 2 and has an atomic weight of 15.9994, so it has an equivalent weight of 7.9997. [edit] Calculations A simple equation with moles and the coefficient number of limiting reagents and products, known as the Moum method, will give the number of moles of the unknown quite simply. This can be re-arranged to give the Lecce method:
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