SSLink Posted July 12, 2005 Report Share Posted July 12, 2005 Re the thinner on the paint issue, please realize that there is a big difference between normal paint thinner (mineral spirits) and stronger solvents like xylene, toluene, acetone, etc. I used to use xylene as a booster and was always careful to avoid getting it on my car's paint finish. I am not a chemist, but I do believe that these solvents as petroleum derivatives are further refined than gasoline, and actually burn cleaner. They are normal additives present in the pump gas you buy anyway. When leaded gas was outlawed the oil companies had to resort to other ingredients to boost octane and burn cleaner. Link to comment Share on other sites More sharing options...
haynss Posted July 12, 2005 Report Share Posted July 12, 2005 i got a question. if im tuned for 91 octane and just before i go to the track i put some 101 in, will that affect the running of my truck in a negative way for that little 1/8-1/4 tank that i have in there? I wont stay on 101 but ill go back to 91 after that. Link to comment Share on other sites More sharing options...
SSLink Posted July 12, 2005 Report Share Posted July 12, 2005 If you're properly tuned for 91 you really shouldn't need to add the 101. If you do as a little KR insurance it won't hurt to have a little higher average octane in your tank afterward. Higher octane alone isn't going to give you more power. You have to be tuned more agressively to take advantage of it. Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted July 12, 2005 Report Share Posted July 12, 2005 i got a question. if im tuned for 91 octane and just before i go to the track i put some 101 in, will that affect the running of my truck in a negative way for that little 1/8-1/4 tank that i have in there? I wont stay on 101 but ill go back to 91 after that. <{POST_SNAPBACK}> Going with dual pumps, Makani? If not, WHAT ARE YOU CRAZY?? and if so, up that to 3/8 to 1/2 Link to comment Share on other sites More sharing options...
haynss Posted July 12, 2005 Report Share Posted July 12, 2005 ok so 3/8-1/2 it is Link to comment Share on other sites More sharing options...
misterp Posted July 12, 2005 Report Share Posted July 12, 2005 i got a question. if im tuned for 91 octane and just before i go to the track i put some 101 in, will that affect the running of my truck in a negative way for that little 1/8-1/4 tank that i have in there? I wont stay on 101 but ill go back to 91 after that. <{POST_SNAPBACK}> Assuming your tune is already perfect: your times will suffer because higher octane fuels have a slower moving flame front (slower burning); that means you have to put in more timing advance to start the burn earlier to compensate. Link to comment Share on other sites More sharing options...
misterp Posted July 12, 2005 Report Share Posted July 12, 2005 ... I do believe that these solvents as petroleum derivatives are further refined than gasoline, and actually burn cleaner. ... Depends what you mean by cleaner; yes the level of unburnt hydrocarbons will be reduced (more complete burn) but output of benzene into the atmosphere will increase; how much I dunno... Mr. P. Link to comment Share on other sites More sharing options...
oscareltemblo Posted July 12, 2005 Author Report Share Posted July 12, 2005 Man you guys know your stuff Link to comment Share on other sites More sharing options...
deezel Posted July 13, 2005 Report Share Posted July 13, 2005 misterp, good synopsis above on the applications of fuel additives. ... I do believe that these solvents as petroleum derivatives are further refined than gasoline, and actually burn cleaner. ... Depends what you mean by cleaner; yes the level of unburnt hydrocarbons will be reduced (more complete burn) but output of benzene into the atmosphere will increase; how much I dunno... Mr. P. <{POST_SNAPBACK}> Actually, aromatic hydrocarbons (such as the solvents benzene, xylene, toluene; and larger ones like napthalene) produce a less complete burn. The intermediate species that form when the 'benzene' rings break are more stable and resist further oxidation compared to straight-chain hydrocarbons. Aromatics are known for soot production - this is why. For the same reasons, aromatics do have higher octane ratings because they burn slower and contain more energy in their resonance-bonded aromatic rings. They are useful as additives in the ~1-20% range. And, they will increase exhaust emissions due to the same reasons. here's some related text on combustion, octane, and knock... 6.3 What fuel property does the Octane Rating measure? The fuel property the octane ratings measure is the ability of the unburnt end gases to spontaneously ignite under the specified test conditions. Within the chemical structure of the fuel is the ability to withstand pre-flame conditions without decomposing into species that will autoignite before the flame-front arrives. Different reaction mechanisms, occurring at various stages of the pre-flame compression stroke, are responsible for the undesirable, easily-autoignitable, end gases. During the oxidation of a hydrocarbon fuel, the hydrogen atoms are removed one at a time from the molecule by reactions with small radical species (such as OH and HO2), and O and H atoms. The strength of carbon-hydrogen bonds depends on what the carbon is connected to. Straight chain HCs such as normal heptane have secondary C-H bonds that are significantly weaker than the primary C-H bonds present in branched chain HCs like iso-octane [21,22]. The octane rating of hydrocarbons is determined by the structure of the molecule, with long, straight hydrocarbon chains producing large amounts of easily-autoignitable pre-flame decomposition species, while branched and aromatic hydrocarbons are more resistant. This also explains why the octane ratings of paraffins consistently decrease with carbon number. In real life, the unburnt "end gases" ahead of the flame front encounter temperatures up to about 700C due to piston motion and radiant and conductive heating, and commence a series of pre-flame reactions. These reactions occur at different thermal stages, with the initial stage ( below 400C ) commencing with the addition of molecular oxygen to alkyl radicals, followed by the internal transfer of hydrogen atoms within the new radical to form an unsaturated, oxygen-containing species. These new species are susceptible to chain branching involving the HO2 radical during the intermediate temperature stage (400-600C), mainly through the production of OH radicals. Above 600C, the most important reaction that produces chain branching is the reaction of one hydrogen atom radical with molecular oxygen to form O and OH radicals. The addition of additives such as alkyl lead and oxygenates can significantly affect the pre-flame reaction pathways. Antiknock additives work by interfering at different points in the pre-flame reactions, with the oxygenates retarding undesirable low temperature reactions, and the alkyl lead compounds react in the intermediate temperature region to deactivate the major undesirable chain branching sequence [21,22]. oscareltemblo, you have to be careful what questions you ask around here! Link to comment Share on other sites More sharing options...
SSLink Posted July 13, 2005 Report Share Posted July 13, 2005 Like I said... Link to comment Share on other sites More sharing options...
misterp Posted July 13, 2005 Report Share Posted July 13, 2005 ... ... I do believe that these solvents as petroleum derivatives are further refined than gasoline, and actually burn cleaner. ... Depends what you mean by cleaner; yes the level of unburnt hydrocarbons will be reduced (more complete burn) but output of benzene into the atmosphere will increase; how much I dunno... Mr. P. Actually, aromatic hydrocarbons (such as the solvents benzene, xylene, toluene; and larger ones like napthalene) produce a less complete burn. The intermediate species that form when the 'benzene' rings break are more stable and resist further oxidation compared to straight-chain hydrocarbons. Aromatics are known for soot production - this is why. For the same reasons, aromatics do have higher octane ratings because they burn slower and contain more energy in their resonance-bonded aromatic rings. They are useful as additives in the ~1-20% range. And, they will increase exhaust emissions due to the same reasons. ... Thanks deezel, did not know that Mr. P. Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted July 13, 2005 Report Share Posted July 13, 2005 Ok Mr. P and Deezel -- get over in Makani's Meth injection thread and explain it to us ;) Link to comment Share on other sites More sharing options...
mbpsychoSS Posted July 13, 2005 Report Share Posted July 13, 2005 Nice to know i have a bottle of lead substitute i may try on the next fill up Link to comment Share on other sites More sharing options...
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