In this article, I will discuss Avgas, Mogas, White Gas, Fuel Restoration Tips, Fuel Storage, and some Cold Weather Tips.
Introduction
When it comes the various internal combustion engines, we must conserve and preserve fuels for as long as it is feasible. In the cold northern climates, keeping a chainsaw running is a serious concern. We can use ‘work around’ solutions, or methods, in other words, expediant techniques to improve and use old fuel stock, as our fuel supply will necessarily be limited in a partial or total collapse situation. We must necessarily reduce the demand and our expectations, and learn to do without the modern level of power and convenience we’ve become to expect. For the sake of brevity, I’ll limit the discussion to areas that are seldom discussed. This is not an exhaustive attempt.
Background
I have 20 years of experience on the logistics side of a major domestic disaster preparedness/emergency services operation. And, I have over 40 years of experience in the automotive business. I am also a survivalist who has ‘lived it’, for the last decade. I grew up without a father. Out of necessity, I changed my first flat tire at the age of 10, and started working on things mechanical and electrical. I received my driving license at the age of 14, and crashed my first car by age 15. Remember the movie American Graffiti? I lived that. The second car was a 1969 Ford Galaxy 500 with a 390ci big block, and the other was a 1956 Pontiac Chieftain. The Chieftain was essentially a Chevy Bel Aire. By age 16, I had to remove engine cylinder heads to recondition exhaust valves damaged by excessive heat erosion. Fortunately, I had a friend with a full shop set up for working on his dragster, and re-ground the valves there. I learn the hard way, but I’ve found I usually learn fast and best, when I learned the viking way — the “sink or swim” way. The water will be cold, but just jump right in, and get it done.
Given my experience with engines at a young age, I became aware of how and why unleaded fuel burned, and damaged countless thousands of exhaust valves in motors not designed to handle the higher temperatures that unleaded fuels produced. When unleaded ethanol fuel was introduced, there was once again, a great deal of damage done to older motors. I’m no expert, yet after much real-life experience, experience wrenching on vehicles, and repairing emission control systems for a living, and latter, managing hundreds of thousands of dollars spent annually on automotive maintenance, I’ve developed some understanding about fuels and fuel systems, fuel injection and carburetor based systems. It is important to choose the correct fuel for an application, lest the motor becomes damaged, or will not perform as needed.
Fuel Type: Non Ethanol Unleaded Premium Grade Automotive Gasoline (Mogas)
Non-ethanol unleaded premium gasoline is the best to store and use for modern vehicles with modern emission control devices. In all engines, it will not harm the original carburetor gasket material that are not designed to withstand the corrosive effects of 10% ethanol blended fuels. There are still older generators and chainsaw in use or in storage, that were not designed for use with non-ethanol fuel. Non-ethanol unleaded premium grade gasoline treated with a fuel stabilizer such as Pri-G (gas), will start and run a standard compression vehicle motors well after 3 years of storage, and perhaps a tad longer. Modern gasoline fuels are loaded with additives. That is the gummy stuff that gums up fuel systems, and why a fuel stabilizers is needed to keep these additives suspended in the fuel. A fuel stabilizer will not protect the fuel from oxidization, or evaporation, however.
White gas that is used in Coleman type lanterns and stoves, and Avgas do not have any, or many additives, therefore they do not need a stabilizer. When they evaporate, there is no residue. Avoid running an ethanol blend fuel in 2-cycle motors because of the risk of water becoming adsorbed by the ethanol that is hydrophilic (readily absorbs water). As an emulsion of oil and water is created, there is the risk that this fuel, once saturated with water, and then blended with 2 cycle oil additive, may not lubricate as effectively as needed.
There are many old chainsaws that are still serviceable, and might put back into service. My favorite is a 35 year old Husky (Husqvarna), an L65. These old saws have an advantage as they can tolerate lower octane fuels. Mine is reliable, and ran fine on 2-year-old premium non-ethanol gas without trouble. Modern high performance saws that require 91 octane fuel at a minimum, will likely not fair as well in the Third World conditions of our future. If the fuel is old, the octane rating is well below what is required by the manufacturer for their modern saws. Be careful not to run these saws so hard that the saw becomes very hot. If pinging is heard, let it cool off, and cut slower. The piston could easily be melted through. I store lots of Avgas, primarly for my saws, and small generators.
Aviation Fuel: Avgas 100LL
This is available at a local private airport. To extend the maintenance schedule, and to further reduce the risk of gumming up the carburetor, and damaging a saw motor, but primarily as a for a fuel for long-term storage, I’ve recently switched over to AVGAS 100LL. The designation ‘100LL’ translates into 100 octane/low lead. This is an octane rating as determined by another method and metric for small aircraft. The octane rating as measured for automotive fuels is only 96. The lead in the fuel will deposit on spark plugs and valves. There is a significant amount of lead in this fuel. Do not use this fuel in modern vehicles with emissions control devices. It will quickly coat, and ruin oxygen sensors and catalytic converters. But it runs vintage vehicles without these emission control devices, very well.
Lead increases the octane level, and lubricates and cools top end engine parts, pistons, and valves. It is a pure gasoline with lead as it’s primary additive, yet it does not contain any of the additives that can cause fuel systems to fail. Because lead is naturally stable, the octane rating of this fuel does not degrade. It is after all, intended for aircraft that require the highest standards of reliably. I’ve concluded after much research that Avgas can remain good to use for as long as 5 to 10 years without a fuel stabilizer added, if properly stored. Mine was purchased last year at only $5.00 per gallon.
My saws run on this as well, but in very cold weather, a little ether (quick start), or propane is needed to get them to start. The lead in this fuel will also act as a lubricant in 2-cycle motors. Because the octane rating is 96, higher than chainsaw are generally designed to run on, the saw can actually run a bit slower, yet it is better to have a fuel for long term storage that has an excessively high octance level as it goes into long terms storage where and when the octane level begins to degrade. IMHO, Avgas does not lose its octane level quickly as automotive gasolines, because of its lead content.
Avgas is designed for aircraft motors that are operated, at more or less, a constant RPM, around 3,500 RPM. It does not contain as much of the ‘light volatile gasses, and other additives that are in automotive gasolines. Bubbling propane into Avgas used in saws, or other engines, or into fuels that have been stored for an extended period, or not stored in ideal conditions, can improve their ability to start the engine in very cold weather, and improve throttle response. Starting the engine in very cold weather can be more difficult if it is pull-start motor, and the fuel is old, or if it is running Avgas. During the other three seasons, I’ve discovered no other problems with its use. The benefits of using Avgas more than outweigh the disadvantages of using Avgas in that we have a fuel that can be stored for many times longer than automotive gasoline, and it will not degrade the gasket materials, or clog the fine passageways inside carburetors with residue that is deposited by automotive fuel when it evaporates, or degrades.
The many additives used to reduce emissions, and improve drivability, contain chemicals, that when the fuel degrades or evaporate, are deposited in passageways of fuel systems that eventually become blocked. This is the common cause of failure to start and run in primarily small engines, and some large engines. The smaller the carburetor, the more rapidly it can become clogged up. The longer in duration a motor that uses a carburetor is stored, the more likely it will become clogged up. Chainsaws have tiny carburetors with passageways less in diameter than a sewing needle, and are often stored with degrading fuel for long periods of time. For me, this is another reason why Avgas is clearly the best fuel to use and store. I’ve replaced and rebuilt countless chainsaw carburetors over the decades. Here in cold country, a chainsaw is perhaps the most important motorized piece of equipment one processes.
White Gas (Coleman Fuel)
White gas is naphtha, a pure fuel with an octane rating of only 55, yet even if it looks good, it is not suitable (by itself) for most engines. After many years of storage, it may not produce as much heat or light. White gas fuel after 10 years of storage is not as potent, even if runs the lamp, cook stove, or catalytic heater, and it will, it does not produce as many BTUs as it once did. Do not attempt to use this fuel to run anything other than the lowest compression motors with a compression ratio closer to 7-to-1, such as vintage generators and motorcycles.
(To be concluded tomorrow, in Part 2.)