OK - Now its Oil!

[mbopp]

Tundraotto: I was just forwarding what another poster had in TSF. Stihl's website says their low smoke oil meets JASO and ISO standards. I just picked up a bottle of Echo premium oil that says the same thing. I don't know if either of them are synthetic or not.

Mike

 

[Fish]

Sorry Rick, I disagree with the 87 octane myth. I just do not
believe it. If this was the true cause of failure you would see
a widespread epidemic of two cycle failures, not just a few.
I have fought this emotional battle before, but get real. If
this was the case, there would be stacks of burned up
two cycles at every shop, and it would not be a secretive
theory that it is at the moment. Just because it says to use
a certain octane level in a manual, which the octane rating
is a topic of debate as well, does not mean that using
regular will result in a ball of fire. I have worked on this stuff
for a while and find that this octane debate is silly. You will
note that many manuals recommended 10w40 on lawn mowers
and that failure has a little more reliable documentation.
I know everyone here is comfortable in their premium fuel bliss,
but just because it costs more it must be better logic is
childish, especially since the posters here purport expertise
on various subjects, they could come up with a better arguement,
I would think. I think the burden of proof should rest on the
shoulders of the folks that say that regular fuel will cause the
saw to melt, and not on the majority of this continent that just
use regular unleaded with no problem.
Fish

 

[tundraotto]

we meet again fish - its not a myth if my trimmer pings when cold on 87 octane and it does not ping with 89, 91,92,93 or 96 octane - pinging is not good the way i understand it and if the 87 octane allows it to ping....well - the octane does make a difference.

PS. mbopp - i think they oils you listed are synthetic or semi-synthetic (as they are low smoke oils) - could not find any more info on them that would state that as a fact though,

 

[tundraotto]

i did find that echo's premium oil that we are talking about is made by citgo and they have a consumer info line that they promise to answer specific questions RE: Oils during business hours if someone would bother..

1-800-248-4684 or 918/495-4746

 

[Fish]

Drat!
Foiled again!
If you say it pings, it must be fact!
Must you foil all my plans?

 

[tundraotto]

lol, it doesnt ping anymore...

 

[Fish]

How many different pumps do they have in a gas station in Ark?
89 octane must be pretty bad too, {slight pinging?}
Are you saying 89 is OK? I am sure you will have a fight there too
So you are a synthetic nut too? How can you tell that this is
superior? A certain feeling of well being? I have a large stack
of two cycles that are dead due to using regular two cycle oil
right beside my low octane stack. If only everyone used premium
and synthetic oil mix, there would not be one Electrolux saw
in the junk pile. Preignition is a killer that must be stopped!
Saying a saw runs better is one thing, saying the piston melts
because of octane is another. I have not witnessed either,
so I will argue the point.
I did not roll over on this topic, and saying that the saw
doesn't ping or seems to run better is not quite sufficient.
Can you offer any empirical proof?

 

[Darin]

89octane is recommended cause it burns slightly cooler than 87octane. In 2cycle this is important. Studies show 12 degrees less! Not much but a little cooler. Not only does it burn smoother but more effiecient.

Echo oil and Husky XP oil are one in the same. They are actually a better oil than stihl in my opinion cause it has a fuel stabilizer in it.

 

[Fish]

Why?
What studies?

 

[tundraotto]

all stihl 2cycle oils provide a fuel stabilizer in them.

fish: - in arkansas i can get:

87, 89, 91 at almost all the stations
92 at conoco and a couple of others
93 at exxon
96 i have mixed myself with an an octane booster

i never said i melted a piston due to 87 octane. i said my trimmer pings with 87 when cold and it does not ping cold with the higher octanes!! i havent done a scientific study on pinging - all i can tell you that it pings with 87 and it DOES NOT PING WITH ANY OTHER OCTANE LEVEL I HAVE TRIED!! I can reproduce this test at my will just by running 87 octane - im not saying this is a cure-all - but you cant tell me that "a little" pinging doesnt matter....its not good.

 

[tundraotto]

ps. fish - you said you had never seen a burned through piston.
this one from a suzuki 250cc 4wheeler

 

[tony marks]

here we go again.boys i think the best idea may be to try it both ways,an use the one that cranks easier and seems to run better.
especially in a hard hot run. later on now.

 

[Fish]

Otto knows I don't want any trouble, but why should we believe
that piston was damaged by 87 octane?

 

[Gypo Logger]

Hi Otto, judging by the picture of that piston, I would say there wasnt enough air in the tires.
John

 

[tundraotto]

this piston melted due to pre-ignition which lead to too high of combustion temperature. too low of a gas octane is more likely to preignite. thats all i can tell you - i cant prove anything "empirically" in this case.

 

[Gypo Logger]

Or the antenae wasnt out far enough.
John

 

[Darin]

why higher octane burns cooler

Fish,
It did in older engines using carburetors to regulate air/gas mix They cannot as accurately regulate the air/fuel mix going into the engine as a computerized fuel injector. Carburetors need adjustment, as a part of regular maintenance, to keep the air/fuel mix as accurate as possible. So many times, these adjustments were not made regularly causing too much fuel to be mixed with the air. When this happened the gasoline would not burn completely soaking into carbon deposits. This would cause a premature ignition of the gasoline due to the intense heat in the engine cylinder creating "engine knock." When this happened, people would change to the higher octane/slower burning gasoline to resist the premature burn, thus minimizing the knocking problem. I don't have to show you studies. Higher octane simply doesn't burn as fast....therefore keeps a cylinder cooler.

Tundra--you are right on the Stihl oil...I forgot.

If it for your car and you dont here a pinging higher octane is worthless.

 

[Cicero]

Darin is right on his statement about octane. However, keep in mind that what causes the knock is no so much preignition as much as it is uneven ignition.

As the spark-ignited flame progresses across the piston it is the unstable fuel (lower octane) which explodes instead of burning. Therefore, preignition will usually occur in the direction of the burning flame front. I suppose that a burned piston could be a result of this, however, the design of the combustion chamber and piston determine the flame front. The underside of the piston is cooled by the oil contact from the crankcase. So who know??

Combustion deposits dont necessarily retain fuel as much as they change the compression ratio, thus a higher octane fuel may compenstate for that change.

Otto, I have no answer why your trimmer pings only at lower temps and does not at higher with your 87 octane. An increase in temp should increase you octane requirement. Decrease in temp should decrease you octane requirement. Altitude and barametric pressure will also effect octane. As far as the automotive engine is concerned knocking generally will not cause any damage to an engine. However, if real severe and done over a prolonged period of time it can.

Last I knew Echo required an 89 octane.

talked enough.

later

 

[Harley]

John,

I disagree. I think it was the foot peg on the left side, not the antenae.

Everybodies entitled to their own opinion. Fish if you want to run 87 then run it. I'm not gonna come down there and secretly add octane booster to your mix for ya. Same thing for Otto, except insert dog pee instead of octane boost.

I'll tell you one thing that interests me. I got gas for my old man once. He runs a 028 super. He usually gets me to get him regular(87) for the mowers. So I got him regular for the saw. I never told him it was regular. A couple of weeks later, I'm doing something in the garage and he comes over and asks me "you got me regular gas didn't you?". I said yes. He said I thought so, I could feel the difference. He said that it didn't pull as well as it usually does. From now on I get him 89 or 92, depending on where I get it. No complaints. And no his piston didn't burn up either.

For me, I proably use less than fifteen gallons a year, so whats the price difference come out to. 2.25 if you figure .15 cents difference. My five hundred dollar toy/investment is worth that 2.25. Hell, even if you spent 25 dollars more its worth it to me.

Even if you can't see that benefit, you can't argue that its bad for the saw.

Just my two cents.
Who's on deck?

PS. Big, I guess you've never taken apart many bearing failures?

 

[Fish]

I don't really worry about whether you all run premium or
not, I have tried all octanes and noticed no difference.
I have not noted an epidemic of piston failures that can
be blamed on octane, or any for that matter. I have heard
people try to blame octane when they have a failure, but I
am sure the fault lies elsewhere. If you all have modified
your saws to the point that you have dramatically raised
your saw's compression ratio, then a higher octane would be
needed, but for normal 2 cycles the regular unleaded that
is sold around here works fine. In other parts of the world,
who knows? I am not preaching to you all to use regular, as
no one around here would ever change their mind anyway.
I just am saying that I refuse to believe this type of engine
failure can be blamed on 87 octane. If your saw runs better on
premium, by all means use it. Of course there are always
some jokers that deduce that higher octane= better, so they
are hunting for some super high octane racing fuel and they
will swear by that. 100 + octane, splitfire plug, synthetic oil
mix, slick 50, amsoil, Marvel Mystery oil, wd40, etc...

People are quite passionate about what they believe, which is
great. I will even get you all even more worked up.
I sell Champion Spark Plugs! Do your worst!............