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Octane ? What do you put in your saw?

Post in 'The Gear' started by basswidow, Mar 5, 2010.

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  1. North of 60

    North of 60 Minister of Fire

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    Now your talking. Canada is the home of high octain legal beer. The north even gets away with more on the shelf. :coolsmile:

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  2. Nonprophet

    Nonprophet Minister of Fire

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    Thanks for doing the right thing and asking how to properly dispose of it--with nearly 7 billion of us on the planet now every little thing we can do to minimize our impact makes a difference!!

    About 5 years ago we had 20 gallons or so of old diesel we needed to get rid of. We didn't just want to dump it in the woods somewhere or burn it, so I called the local fire department, they had no suggestions. I called the DEQ, they said that most places that do oil changes will take old fuel for free as they get paid for the old oil. Another alternative they mentioned was to pour it into a shallow metal or plastic pan and place it in the sun where it would evaporate eventually. I didn't want to worry about kids or pets coming into contact with it, so we took it to a local service station and they added it to their used oil container for free.

    NP
  3. ChipTam

    ChipTam Burning Hunk

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    Not sure about their saws but Stihl recommends high octane for their weed whips. Since I read that in their manual and switched to high octane, the weed whip starts a lot easier.
    ChipTam
  4. Nonprophet

    Nonprophet Minister of Fire

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    Quoted from the Stihl MS361 manual:

    "Use mid-grade unleaded gasoline with a
    minimum octane rating of 89 (R+M/2). If
    the octane rating of the mid-grade
    gasoline in your area is lower, use
    premium unleaded fuel.

    Fuel with a lower octane rating may
    increase engine temperatures. This, in
    turn, increases the risk of piston seizure
    and damage to the engine.

    The chemical composition of the fuel is
    also important. Some fuel additives not
    only detrimentally affect elastomers
    (carburetor diaphragms, oil seals, fuel
    lines, etc.), but magnesium castings and
    catalytic converters as well. This could
    cause running problems or even
    damage the engine. For this reason
    STIHL recommends that you use only
    nationally recognized high-quality
    unleaded gasoline!"

    I checked 3 Husky manuals (455, 372, 395) and all three said minimum of 87 octane.


    NP
  5. smokinj

    smokinj Minister of Fire

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    and there you have it!!!!!!!!
  6. wendell

    wendell Minister of Fire

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    91, no ethanol here, Amsoil Sabre
  7. StackedLumber

    StackedLumber New Member

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    can I get a vote for no-lead Aviation Gas?? (I believe oct. 100) No ethanol-available at airports and some gas stations. Saw runs great, and I don't have to worry about ethanol corrosion
  8. ikessky

    ikessky Minister of Fire

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    Doesn't most of the pre-mix oil have a fuel stabilizer in it because of the ethanol now?

    On many late model computer controlled cars, running a higher octane will allow the computer to advance the timing more. It is still, however, controlled by the parameters of a stock chip/tune.
  9. basswidow

    basswidow Minister of Fire

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    Really glad I posted this question. I swear this IS the place to get answers and shorten the learning process. When I posted - I thought the higher octane would burn hotter and be prone to cause more damage and my 87 octane was safer. I was completely backwards with that line of thinking. I am gonna burn 93 from here on out - not only in my chain saw, but also in my weedeater. I should have also done the same in my outboard motor too.
  10. Tony H

    Tony H New Member

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    an easy was to git rid of a small amount like that is to add it to your truck when you do the next fill up ,mixed in with the rest of the fuel your engine will never know.
  11. Tony H

    Tony H New Member

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    Your first sentence is correct and accurate.
    The second sentence buys into the old wifes tale if regular is good premium must be better .
    By your example if you rev your Tacoma hard and haul some weight then it should be using premium because some how that alters the engine compression and requires additional anti detonation protection ? Sound silly to you ?
  12. Tony H

    Tony H New Member

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    Don't forget the lawnmower, leaf blower, and the log splitter. :red:

    I put premium in my splitter and ........ it split exactly the SAME as it did before.

    Sorry buy you got the wrong message higher octane will not help in any way with those engines.

    Don't listen to me just google premium gas and see all the articles by : automotive publications, scientists and engineers from big oil companies, car companies , FTC and other gov sources that will confirm this is true.
    The only one you might have trouble finding is one from an oil company.
  13. FireAnt

    FireAnt Minister of Fire

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    Tony +1. Octane has to do with engine compression. Everyone may know this but I put it up.

    Higher octane ratings correlate to higher activation energies. Activation energy is the amount of energy necessary to start a chemical reaction. Since higher octane fuels have higher activation energies, it is less likely that a given compression will cause autoignition.

    It might seem odd that fuels with higher octane ratings are used in more powerful engines, since such fuels ignite less easily. However, an uncontrolled ignition is not desired in an internal combustion engine. The fuel must be fired at a precise time. An ignition too early will cause the resulting forces to try to turn the crankshaft in the reverse direction. This will not cause the engine to rotate in the reverse direction because of the kinetic energy in the rotating assemblies and the flywheel, but will strain the crankshaft. This strain is the source of the characteristic 'ping' noise heard during detonation. This reduces power output, because much of the energy is absorbed as strain and heat in parts of the engine,[citation needed] rather than being converted to torque at the crankshaft.

    A fuel with a higher octane rating can be run at a higher compression ratio without causing detonation. Compression is directly related to power (see engine tuning), so engines that require higher octane usually deliver more motive power. Engine power is a function of the fuel, as well as the engine design, and is related to octane rating of the fuel. Power is limited by the maximum amount of fuel-air mixture that can be forced into the combustion chamber. When the throttle is partially open, only a small fraction of the total available power is produced because the manifold is operating at pressures far below atmospheric. In this case, the octane requirement is far lower than when the throttle is opened fully and the manifold pressure increases to atmospheric pressure, or higher in the case of supercharged or turbocharged engines.

    Many high-performance engines are designed to operate with a high maximum compression, and thus demand high-octane premium gasoline. A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.

    However, burning fuel with a lower octane rating than required by the engine often reduces power output and efficiency one way or another. If the engine begins to detonate (knock), that reduces power and efficiency for the reasons stated above. Many modern car engines feature a knock sensor – a small piezoelectric microphone which detects knock, and then sends a signal to the engine control unit to retard the ignition timing. Retarding the ignition timing reduces the tendency to detonate, but also reduces power output and fuel efficiency.

    Most fuel stations have two storage tanks (even those offering 3 or 4 octane levels), and you are given a mixture of the higher and lower octane fuel. Purchasing premium simply means more fuel from the higher octane tank. The detergents in the fuel are the same.

    The octane rating was developed by chemist Russell Marker at the Ethyl Corporation c1926. The selection of n-heptane as the zero point of the scale was due to the availability of very high purity n-heptane, not mixed with other isomers of heptane or octane, distilled from the resin of the Jeffrey Pine. Other sources of heptane produced from crude oil contain a mixture of different isomers with greatly differing ratings, which would not give a precise zero point.
  14. bogydave

    bogydave Minister of Fire

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    +2
    Marketing is everything.
    If you ever get confused remember this : It is about the money $$
  15. mainemaul

    mainemaul New Member

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    i run hi test in all my small engines and they all love it,here in maine we have ethanol so i add STARTRON to everything that might sit and never have fuel issues
  16. Tony H

    Tony H New Member

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    It's the additive that does it not the hi test , Stabil , Chevron techtron,wynns,and Starbright startron are all non alcohol additives .
    Note most if the other additives add MORE ALCOHOL to your fuel and that's not what you want is it. Check the label on your favorite additive.
  17. Bill

    Bill Minister of Fire

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  18. firefighterjake

    firefighterjake Minister of Fire

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    I used to run hi-test in the small engines (ie. chainsaw, tractor, weedbeater, etc.) but a long time ago I discovered that they pretty much run just as well with the cheap(er) stuff. Like Maine Maul I do use Star-Tron as a non-alcohol stabilizer in the fuel tanks when the equipment will be sitting for a while . . . which reminds me . . . I need to add some to my sled since I think sledding is done for the year here.
  19. Tony H

    Tony H New Member

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  20. Tony H

    Tony H New Member

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    I kept forgetting so now I add Stabil to the gas cans when I take them to get filled and all the small engines get treated gas.

    Heck I have tried for a while now to convince my in laws they don't need to run everything "out of gas" because that leaves some remnants in the system anyway but to no avail. You should see them all running the boats out of gas when we are loading up after a trip. Hey that's what Grandpa taught them and that's good enough for them ...... then again Grandpa regularly hooks himself and his fishing partners and runs into the dock with the boat and they don't do that !! :bug:
  21. firefighterjake

    firefighterjake Minister of Fire

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    Have you checked to make sure it's the Sta-bil without any alcohol? I've heard the marine grade Stabil is good stuff.
  22. Bill

    Bill Minister of Fire

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    I started putting a little stabil or seafoam in all my gas cans when I fill them up. That way if something isn't run for a while or I have left over gas at the end of the year I know it's already treated. Those pint bottles last pretty long and it's cheap insurance. Maybe I just have too many toys.
  23. lowroadacres

    lowroadacres Minister of Fire

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    I am starting to get frustrated reading this thread.

    I am not aware of anywhere that I can buy gasoline without ethanol as it is mandated by law here in Manitoba that every gas station/fule company has to have a certain percentage of ethanol.

    Any suggestions from around the wood burning world as to where I can get ethanol free fuel?

    I am wondering about av gas or motorcycle racing fuel?
  24. fyrwoodguy

    fyrwoodguy Feeling the Heat

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    currently i run AV 100 LL fuel from the local airport,plus that's what goes into the new saws i sell too.i have run VP 105 unleaded race gas for years untill the fuel spiked to $9.00 per gal.which put me back to AV gas (which is where i started 20 years ago)
  25. charly

    charly Guest

    I've always ran 93 octane, amsoil, and seafoam. Never had any carb, fuel line, or diaphram issues, nothing. I can buy ethanol free gas by me, two different places. I was told the higher octane has less ethanol. Don't know how true that is. Something new I found, VP racing fuel came out with a new Small Engine Fuel: SEF 94. 94 octane and the web site states that it will soon be available in gallon and quart containers too. Not aware of a price yet. I read where AV Gas builds alot of deposits in two stroke motors. Some paramotor companies recommend auto gas over AV gas.
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