Reviving Old Tractors with Lead Substitutes
By Tom Seest
At ClassicTractorNews, we help classic tractor lovers keep up with the latest news for classic and vintage tractors.
Historic tractors that used kerosene or gas blends such as TVO can still run on those fuels, but not on today’s unleaded gasoline. Unleaded gasoline may damage valve seats of older engines, leading to micro welds forming that cause failure.
Specialists assert that classic car engines may not be affected, while old farm equipment will. These machines require lead’s lubricant properties as an essential component for reliable operation.
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Unleaded gasoline has gradually replaced leaded gas at many pumps in the United States and around the world, as its benefits for engine performance outweigh any risks to human health and the environment. Furthermore, emissions produced are significantly less. Unfortunately, however, certain older vehicles require lead for proper functioning. An additive designed to replace lead will help ensure these vehicles continue running well.
Before the new additive becomes widely available, most older cars and other vehicles that rely on lead fuel will need to switch over to regular unleaded gas (87 octane gas). This type of fuel doesn’t contain any lead and is, therefore, safer for your engine; plus, its lower octane rating makes it suitable for vehicles equipped with advanced emission control systems designed to respond well to higher octane levels.
Environmental Protection Agency sets the octane ratings of different kinds of gasoline, and two popular varieties are mid-grade and premium gasoline. Of these two choices, mid-grade usually has lower octane levels and can often be cheaper. If unsure which to purchase, service station employees can advise. If that fails to help, then their ratings should also be visible on the pump itself.
People driving older vehicles that were built before unleaded gas was introduced are concerned that switching to this fuel will harm their engines, but recent studies conducted by both the Army and Postal Service confirm what earlier studies demonstrated for automobiles: unleaded gas does not cause mechanical damage in heavy-duty vehicles either; over a three year period only four trucks operated using unleaded fuel required valve jobs and two replacements of their cylinder heads, compared with 16 that ran on leaded gasoline.
The Environmental Protection Agency is working closely with user groups of specific vehicles and equipment to assess if certain engines will be at risk when leaded gasoline usage is completely reduced, as well as potential alternative additives that could provide valve lubrication for those engines at risk.
Kerosene, a petroleum-derived liquid fuel, is often used as an economical option to power lamps, stoves, and heating devices in some parts of the world. Additionally, kerosene fuels small engines as a lubricant while being more stable and easier to store than gasoline with a lower flashpoint. Kerosene also makes an excellent heating and cooking fuel for campers and tents while providing moisture to soak items such as poi or fire batons used by entertainers.
Kerosene can serve as an effective lead replacement in some older engine models due to its low flash point and similarity to kerosene. It can be pumped through the carburetor directly to spark plugs for use with carburetors or fed directly into an engine through its fuel line using a nozzle, providing both lubrication and heat for smooth engine operation. In addition, its use as a degreaser makes kerosene great for cleaning bicycle and motorcycle chains before relubrication!
Kerosene became increasingly popular as an alternative fuel source in tractors and other hit-and-miss engines in the early to mid-20th century, often called tractor vaporizing oil (TVO), produced from crude petroleum through distillation. Although this fuel required air preheat and manifold heat to properly vaporize for spark ignition, its compression ratio was lower and caused less ignition knock than gasoline.
Due to its low flash point and high octane rating, diesel was an ideal fuel choice for use during cold weather when engine temperatures would likely remain at lower levels. Furthermore, its relative affordability made it the fuel of choice in many old tractors until diesel engines became widespread.
Kerosene is similar to paraffin and other fuels for small engines; however, its main difference from these other options lies in its higher octane rating than gasoline and other options listed here. In Australia, it’s commonly referred to as power kerosene with an octane range between 88-102.
Most engines that run on kerosene have hardened valve seats. Machining and shrinking them to accept unleaded fuel will not have any adverse effect on their engines – especially since most older models aren’t used heavily enough to reach temperatures high enough to cause microwelding of their cylinder heads.
Aviation gas (Avgas or Aviator’s Fuel) is an aviation gasoline with a high octane rating designed for use in aviation piston engines when Kerosine or Jet Fuel is unavailable, with its characteristic blue hue signifying high octane ratings. Furthermore, Avgas boasts lower vapor pressure than automotive fuels, which is crucial when flying as this helps prevent vapor lock in both the aircraft engine and fuel pump.
Like their automobile industry counterparts, aircraft fuel makers have begun the push towards eliminating lead from aviation fuel as well. Tetraethyl Lead (TEL), used in aviation gasoline (avgas), determines its octane rating. TEL acts to prevent premature detonation that could damage an engine, as well as keep liquid forms of aviation gas from boiling over and vaporizing into a dangerous form.
TEL in avgas serves to evenly burn its fuel during combustion, helping piston engines reduce wear on pistons, cylinder walls, and valves as well as corrosion and deposits that form in their combustion process. The TEL also serves to decrease corrosion deposits on engine surfaces that serve to support piston engines.
There has been some progress toward eliminating TEL from aviation gas (avgas), although this process will likely take time. Many aircraft, including Boeings, Douglas DC-3s, and Lockheed Constellations, as well as military and civilian piston aircraft with high compression ratios requiring fuel with an exceptional octane rating, cannot use plain avgas alone without additional additives being present in it.
Numerous aviation fuels have been developed that can replace leaded avgas. Unfortunately, however, some aircraft cannot run Mogas or car gasoline intended for planes, and ethanol-based aviation fuel can lead to phase separation in high-pressure engines.
As such, leaded gasoline sales appear to be on their way out; however, its use remains legal when used in specific vehicles such as aircraft and classic cars – especially since there are numerous older classics out on roads today that do not require racing or aggressive acceleration.
A diesel tractor is an extremely capable machine suitable for an array of tasks. This is thanks to its highly efficient engine, which generates enough power for it to perform heavy-duty jobs such as traversing difficult terrain and lifting heavy loads while attaching various farm equipment for increased functionality. Furthermore, fuel costs less compared to gasoline, which explains why so many farmers opt for this type of tractor.
Diesel tractors are known for being highly adaptable machines, yet also durable and reliable, thanks to water-cooled engines used within. Water cooling helps reduce internal damage caused by high temperatures while simultaneously increasing engine lifespan and preventing rust formation, saving both money and effort with its use as an alternative to lead engines.
However, it is recommended that you use the appropriate engine oil for your diesel tractor in order to maximize performance without downtime. When buying engine oil, make sure its viscosity meets specifications set forth by vehicle manufacturers as well as additives that improve low sulfur fuel lubricity significantly.
As part of your maintenance routine for your tractor, it is also essential to monitor its diesel fuel. If it has been sitting around for too long, its quality may have degraded; in such an instance, drain and store it in clear glass containers before pouring it back into its respective tanks after eliminating any accumulated moisture.
As previously noted, older gas tractors tend to have poor resale values due to ethanol-proof carburetors not yet becoming available for them. Therefore, it may be wise to upgrade to something more modern that supports ethanol fuel or even consider switching over to draft animal power as soon as possible.
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