corrosion oil-benzine

[pippo82]

Hi.

I wanted to know if someone knew how to tell me if the ambitious oil-blind (miscela) used in the old engines, has a corrosive power; and if you like to do so you can study it.

 

[cacciatorino]

Hi.

I wanted to know if someone knew how to tell me if the ambitious oil-blind (miscela) used in the old engines, has a corrosive power; and if you like to do so you can study it.

I have no memories of corrosion, the only problem was to use rubbers suitable for seals and pipes because the oil of the mixture tended to inflate the rubbers different from the so-called "anti-oil". so to make the seals you could not use an old air chamber.

Bye.

 

[Ezio Olivato]

it is necessary to know the composition of the mixture, the constituent elements the percentages of mixing and calculate the good old ka ( acid constant): corrosion depends on the rate of oxygen reduction of the mixture in contact with the elements of the container and the amount of oxygen present in the reaction environment! !
but for study, pippo82 what do you mean?

 

[pippo82]

the percentage oil gasoline is 3% oil...my problem is to understand if on the metal parts of a two-time motor of a chainsaw I have to consider the corrosion that can give me the fuel mixture, and if you like to take into account it.

 

[Ezio Olivato]

consider the fact that the old reference tables considered gasoline with lead as standard..what is not so today.
because new lead-free benzines are dryer and to achieve an acceptable performance, by the engine it is necessary to increase the percentage of the mixture at least up to 4%. Lead had an antidetonating power, but it also served as a chelante against the corrosive action of petrol on metals.
not at all the base of gasoline is the oil, which turns out to be at the moment still the best degrease of engines and moving parts: changes, clutches, etc...
joining oil means recomposing the original chemical formula of oil that consists of fats (olii) and ethers and esters: in any case highly corrosive molecules. have the power of water in Chinese torture, drop a drop make the hole!!!
also considers the fact that the mixture performs its corrosive action only in the phase before combustion: carburetor, mixer, and power ducts. in the part concerning combustion discharges, corrosion action develops only in the condensation zones of post-combustion vapours: the pot and the exhaust pipe.....and the steam is much more corrosive than the mixture in liquid form!

 

[thor105]

both oil and gasoline have some corrosive power towards steel, but such power is very low compared to the corrosive capacity that have fueled gases, especially if gasoline is green gasoline, which inside contains sulphur parts and thus generate sulphurous and sulphurous anhydrides. and sulphur is known that it corrodes a lot of steel types (especially by ruining some surface treatments).
For this reason it is important that the engines are always well carburized and that the exhaust gases go out quickly from the ducts.

 

[sampom]

Hi.

I wanted to know if someone knew how to tell me if the ambitious oil-blind (miscela) used in the old engines, has a corrosive power; and if you like to do so you can study it.

Sorry, but what do you mean by old engines?
look that the 2t is always in auge and continuously in development (certain, nothing overwhelming, small refinements), always alive and irreplaceable for fans (they are among these:biggrin. different studies on direct injection etc. are only pseudo-ecological commercial policies/interests that have "casted".
in gp up to 250 is still 2t; Are those old engines you think?
in motogp the 4t has upset everything, certain exceptional performances, but the "taste" (and the pilots) of the old dear 500 we forget it.
I do "regularity" (what they now call enduro..), only and exclusively at 2t and, fortunately, I see that many after conversion to 4t are going back:smile:. dealers are the first ones who sell and those who keep the price better.

Anyway,
problems with the mixture I never had. only thing the old tanks in "ferro" could present oxidation if kept firm for years, but more in the 4t alone gasoline (the oil does anything but bad).
sure the advent of the green was a little trick, but worse for the 4t for valve problems, guides etc.
the lack of lead reduces the intrinsic "lubrific" power of gasoline, but it solves with a good substitute additive of lead. increase the percentage of oil does not solve, on the contrary; it modifies the carburetion and smears everything, incrustations etc. etc. with modern synthetic oils and, I repeat, good additives, you can keep percentages just above one % without problems (if you do not constantly turn to manetta, speed competitions, motocross and kart deserve a separate speech.. but there the benzines are certainly not those that we find "to the pump".
green stinks, it is disgusting, toxic, carcinogenic and much more harmful to contact and inhalation than it was the old super (other political/commercial/ecologista move), and it is true that it is badly tolerated by certain tires that in a short time they "decompose". . But how to study the phenomenon I can't tell you, you should ask a chemist.
safe is that current engines and related components have no problem, being born specifically to use it.

greetings
Mar
live the 2t!

 

[pippo82]

thanks for the answers a last thing:I carry out a reverse of a chainsaw and our material is a 40nicrmo7 and 16crni4 I wanted to know therefore if you have to take into account some surface treatment in particular for tree, biella and friction to be applied to our material to avoid the type of corrossion from you described previously

 

[thor105]

...
green stinks, it is disgusting, toxic, carcinogenic and much more harmful to contact and inhalation than it was the old super (other political/commercial/ecologista move), and it is true that it is badly tolerated by certain tires that in a short time they "decompose". . But how to study the phenomenon I can't tell you, you should ask a chemist.
safe is that current engines and related components have no problem, being born specifically to use it.

greetings
Mar
live the 2t!

I understand you're a 2t engine lover, but getting to say that green gasoline is more harmful than the old super with lead seems definitely an exaggeration.
It may certainly be more harmful to inhalation or contact, but if it is for this then the vinavil is probably the worst of all, but all these are liquids that should not be inhaled or come into contact with man. the green gasoline then combined with the catalytic pot has less polluting emissions than the super. Of course, if, in order to increase the performance and above all to save, the catalyst is eliminated, it is true that it pollutes more than the other, but the fault is not gasoline itself, but of those who have eliminated the catalyst.

 

[sampom]

I understand you're a 2t engine lover, but getting to say that green gasoline is more harmful than the old super with lead seems definitely an exaggeration.
It may certainly be more harmful to inhalation or contact, but if it is for this then the vinavil is probably the worst of all, but all these are liquids that should not be inhaled or come into contact with man. the green gasoline then combined with the catalytic pot has less polluting emissions than the super. Of course, if, in order to increase the performance and above all to save, the catalyst is eliminated, it is true that it pollutes more than the other, but the fault is not gasoline itself, but of those who have eliminated the catalyst.

Perhaps you are not aware that currently not all the means regularly on the market and approved are equipped with a catalyst, not to mention the old circulating park (and here is also the "farse" I mentioned earlier). and certainly I am not a supporter of the "to remove the catalyst" or any pseudo-processing (the motors just keep them well and do not need anything else). Bad helmets.
I would like to ask the Commissioner whether he is a member of the Committee on Budgets. . ask a chemist "disinterested".

greetings
Mar

 

[pippo82]

consider the fact that the old reference tables considered gasoline with lead as standard..what is not so today.
because new lead-free benzines are dryer and to achieve an acceptable performance, by the engine it is necessary to increase the percentage of the mixture at least up to 4%. Lead had an antidetonating power, but it also served as a chelante against the corrosive action of petrol on metals.
not at all the base of gasoline is the oil, which turns out to be at the moment still the best degrease of engines and moving parts: changes, clutches, etc...
joining oil means recomposing the original chemical formula of oil that consists of fats (olii) and ethers and esters: in any case highly corrosive molecules. have the power of water in Chinese torture, drop a drop make the hole!!!
also considers the fact that the mixture performs its corrosive action only in the phase before combustion: carburetor, mixer, and power ducts. in the part concerning combustion discharges, corrosion action develops only in the condensation zones of post-combustion vapours: the pot and the exhaust pipe.....and the steam is much more corrosive than the mixture in liquid form!

So according to you nn I have to take into account the bribes for the elements that I have to go to study more in particular: biella, tree to elbows and clutches?
and I can judge the fact that I study corrosion for what you wrote to me, that "corrosion action develops only in condensation zones of post combustion vapours. ...

 

[Ezio Olivato]

*"so according to you nn I have to take into account the bribes for the elements that I have to go to study more in detail: biella, tree to elbows and clutches?
and I can judge the fact that I study corrosion for what you wrote to me, that "corrosion action develops only in condensation zones of post combustion vapours. ...

♪
Sorry, but your question needs clarification: to me it turns out that biella, tree to elbows and clutches are elements that do not come in direct contact with the fuel mixture; It goes without saying that any corrosion (wear) of these elements of the engine is mechanical and non-chemical-physical, such as those produced by the above-mentioned fuel mixture. and therefore the corrosion index would be irresistible compared to mechanical wear!
Therefore it is worth the suggestion that quoted the seals as a weak point of the whole, and I would not forget the piston shaves-oil...beside the exhaust channel of the gases, valves etc., as already mentioned above.

 

[sampom]

*"so according to you nn I have to take into account the bribes for the elements that I have to go to study more in detail: biella, tree to elbows and clutches?
and I can judge the fact that I study corrosion for what you wrote to me, that "corrosion action develops only in condensation zones of post combustion vapours. ...

♪
Sorry, but your question needs clarification: to me it turns out that biella and tree to elbows ....siano elements that do not come in direct contact with the mixture of fuel

And how not? !
in 2t the mixture is aspired in the "carter pump" and then through the travases passes into the cylinder. therefore tree and biella are practically "annegated" in the nebulized mixture. In fact, bench bearings (besides biella) are lubricated by the oil present in the mixture itself. the carter is completely separated from the transmission/change part where instead there is the friction that not, it does not enter absolutely in contact with the mixture but it is bathed in the oil of the change.

. everything in extreme simplified synthesis only for clarity:smile:

greetings
Mar

 

[sampom]

So according to you nn I have to take into account the bribes for the elements that I have to go to study more in particular: biella, tree to elbows and clutches?
and I can judge the fact that I study corrosion for what you wrote to me, that "corrosion action develops only in condensation zones of post combustion vapours. ...

Yes, for the metal parts you can quietly neglect the event (if ever there should be.. I have never seen it, even on very old engines) corrosion "chemistry" caused by the mixture.

and I repeat that the clutch has nothing to do with it, it is not "bagnata" from the mixture; is outside the engine / pump.

greetings
Mar

 

[Paol]

the corrosion phenomenon in the combustion chamber should be limited by the low amount of oxygen present, which is used to burn the fuel. therefore, as other users have already stated, the predominant wear is mechanical wear. stainless steels suffer from corrosion for pitting in the presence of chlorides, which in the mixture I imagine are absent. for more information, you can try to find information about pourbaix diagrams related to your material (potential vs ph). for seals, acrylonitrile-based ones are better resistant to organic components.

 

[Ezio Olivato]

thanks to marco for the clarifications: support for my theses leads me to think that I have not been unbalanced so much; and forgive the poor knowledge of 2t motor architecture! but a little chemistry I had studied at my time!!

 

[sampom]

stainless steels suffer from corrosion for pitting in the presence of chlorides, which in the mixture I imagine are absent.

and however in the engine there are no stainless steel parts (at least not in the "normal" 2t).

greetings
Mar

 

[Ezio Olivato]

But to think about the question of pippo82, hides an insidious question: that is, if in the manual it is necessary to declare that at the end of the exercise the motor and all its parts should be emptied from the non-combust residues of mixture: cause erosion! especially for non-professional use of the tool!!! in fact all the wood cutters I have known, and that used the chain saw to mix, had the same attitude towards the tool: "I use it again tomorrow!"
and never saw one emptying the tank after use!!!! Nice to write manuals!

 

[pippo82]

thank you so much to all for the advice and the disposition in the answers things that in university professors is difficult to find. . .

 

[Paol]

and however in the engine there are no stainless steel parts (at least not in the "normal" 2t).

right objection. I apologize for the inaccuracy.