87 octane with ethanol OR 91 octane ethanol free
- Thread starter konowl
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Depends on many factors mostly compression ratios also air fuel mixtures and the type of head and valves used to make it breath. Most companies are having trouble today with small engines, in case anyone was sleeping. Most of the issues are fuel related. Today any water gets in and ethanol draws water in , you get problems.
Higher octane fuel is more stable burns cooler and slower its definately a safety factor. I bent valves using 87 octane my machine would backfire almost every shut off. Running 91 octane my machine NEVER backfires. Went through this with two small engines.
Especially in the HEAT , colder air -you can get away with it sometimes. Stihl for instance only recommends 89 and up if you call them they will say buy the highest octane you can get so their requirements like most is a minimum requirement.
I prefer to side on caution with ethanol in my engines. Cars are different they can make due computers and electronic fuel and engine timing is all computer driven. I cannot get leaded fuel or without ethanol around here without buying race fuels. When water is introduced to fuels , and it is , ask any boat owner , then the need for safer octane levels helps, IMHO.
Higher octane fuel is more stable burns cooler and slower its definately a safety factor. I bent valves using 87 octane my machine would backfire almost every shut off. Running 91 octane my machine NEVER backfires. Went through this with two small engines.
Especially in the HEAT , colder air -you can get away with it sometimes. Stihl for instance only recommends 89 and up if you call them they will say buy the highest octane you can get so their requirements like most is a minimum requirement.
I prefer to side on caution with ethanol in my engines. Cars are different they can make due computers and electronic fuel and engine timing is all computer driven. I cannot get leaded fuel or without ethanol around here without buying race fuels. When water is introduced to fuels , and it is , ask any boat owner , then the need for safer octane levels helps, IMHO.
Mini Motors
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Higher octane burns slower, therefore isn't done burning by the end of the bang(*) cycle, and hasn't had the force of a lower octane, faster burning fuel. To compensate for this, you would need to start the burn sooner by changing the ignition timing, and maybe delay the exhaust valve opening. What's happening in your mind is even more wrong. You've been brain washed to think "bigger is better", and somehow higher octane is making your engine more powerful, when the opposite is true. Sorta like when you take the muffler off your minibike. It's louder, but it's really not any faster.
(*) Suck, Squeeze, Bang, Blow= the 4 cycles of a 4 cycle engine. Suck = intake, squeeze = compression, Bang = burn(wrongly characterized as an explosion), and blow = exhaust.
The bottom line is this. Unless you have a PHD in engineering, stick with what the maker suggests. Some really smart people designed your engine. You really don't think that you're smarter than they are, do ya? Repair shops all over love people who think they know better. They refer to this as " someone took a golden screwdriver to it".
No more octane isn't bigger, wow. According to you I would be using 118octane or VP fuels , if bigger is better.
READ the manufacturers requirements thay are MINIMUMs. Re- read what I wrote. WATER and ETHANOL are both BAD NEWS and lower detonation , period. Then you BETTER be sure your local gas station is selling you 87 octane and also be sure to store it in a cool dry place for less than three months.
Otherwise use stabilizers. If you trust Briggs or Kohler for octane requirements then good for you. They know so much why so many failures. Go read any lawn forum tons of failed engines from the so called experts.
Small engine makers are having a terrible time with ethanol based engines. WHY? What changed ! Ethanol.
You stick to what you do , I feel better doing what I do. I'm brain washed.
http://www.nbcnews.com/id/25936782/...mechanics-see-ethanol-damaging-small-engines/
Mini Motors
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I apologize if my last post came off so intense. I can get carried away.
And make no mistake. We agree on ethanol. I never said or heard anyone say otherwise. But "so many failures"? I have a dozen or so small engines, that go back into the 50s, and haven't had an issue(although, I do use Sea Foam). And while many complain about ethanol in forums, I never heard of any fatalities.
And make no mistake. We agree on ethanol. I never said or heard anyone say otherwise. But "so many failures"? I have a dozen or so small engines, that go back into the 50s, and haven't had an issue(although, I do use Sea Foam). And while many complain about ethanol in forums, I never heard of any fatalities.
Have been repairing engines since the 60's and ethanol does not seen to create the problem in the older engines. The problem started to show up in the last 5 years. This would lead my to believe that engine manufactures have changed something in their fuel system materials. The aluminum seems to corrode faster and the synthetic plastics are either expanding (float needle and seats) or hardening (fuel lines). Also, fuel companies are now saying their fuels start breaking down after 30 days, which was not a problem before ethanol. Because the passageways and jets in today's carbs are so much smaller, the effects of a small bit of dirt, gum, varnish or corrosion very quickly affect the carbs operation. From my experience I feel that the gum, varnish and corrosion is a result of the addition of ethanol and that is why I recommend using non ethanol fuels whenever possible.
If you have the option! YES, AGREED 100%.
Rick Kitchings has been a small-engine mechanic for about 30 years, and heç—´ been busier than ever lately.
Recently, a customer came into his shop in Savannah, Ga., with a string trimmer that had barely been used. çš„t looked like it just came off the showroom floor, but the motor was absolutely shot, absolutely worn out, Kitchings said.
The owner had fueled the trimmer with an gasoline-ethanol blend, which is becoming increasingly common thanks to a federal mandate to convert to biofuels.
Although the Web is rife with complaints from car owners who say ethanol damaged their engines, ethanol producers and automakers say itç—´ safe to use in cars. But smaller engines the two-cycle utility engines in lawnmowers, chain saws and outboard boat motors are another story.
Benjamin Mallisham, owner of a lawnmower repair shop in Tuscaloosa, Ala., said at least 40 percent of the lawnmower engines he repairs these days have been damaged by ethanol.
展hen you put that ethanol in here, it eats up the insides or rusts them out, Mallisham said. é„*ll the rubber gaskets and parts it eats those up.
The Outdoor Power Equipment Institute (OPEI) has advocated nationally regarding the damaging effects of ethanol-based fuels on small-engine equipment. These fuels, due to their corrosive nature, can seriously damage fuel systems that are not designed to handle them. E15 fuels burn significantly hotter, and as a result, they can cause a small engine to overheat. In addition, these increased-ethanol fuel blends can absorb a great deal of airborne water (which in humid or damp operating conditions makes the engine very difficult to start) and are hard to ignite within a carburetor during cold weather.