What Do Petrol RC Cars Run On?

Petrol RC cars, as the name suggests, primarily run on a petrol-based fuel. This is different from the nitro RC cars, which use a special blend of nitromethane, methanol, and oil.

Petrol RC cars utilize a mixture of regular unleaded petrol and 2-stroke oil, similar to what’s used in chainsaws or some motorbikes.

How to Mix:

Typically, a ratio of 25:1 or 30:1 is recommended, meaning 25 or 30 parts of petrol to 1 part of 2-stroke oil. However, it’s essential to consult the manufacturer’s guidelines for the specific model you own as some may require a different mixture.

Advantages of Petrol-Based Fuel:

Cost-Effective: One of the primary benefits of petrol RC cars is that petrol is readily available and often cheaper than nitromethane. This makes running and maintaining a petrol RC car more cost-effective in the long run.

Longer Run Times: Petrol RC cars generally have larger fuel tanks, and petrol delivers more energy per volume than nitromethane. This means that you’ll experience longer run times and more fun before needing to refuel.
Environmental Concerns: While no internal combustion engine is entirely eco-friendly, petrol burns cleaner than nitromethane, producing fewer noxious emissions.

Some Downsides:

Weight: Petrol engines and their accompanying fuel tanks tend to be heavier than their nitro counterparts. This added weight can impact the car’s agility and speed.
Complexity: Petrol engines can sometimes be more complex and harder for beginners to tune or maintain. Proper care is required to ensure the longevity of the engine.
Safety: Storing and handling petrol requires care due to its flammable nature. Always store petrol in approved containers and away from sources of ignition.

Electric vs. Petrol RC Cars:

It’s worth noting that there are also electric RC cars available, powered by rechargeable batteries. While electric cars offer ease of use, cleanliness, and quiet operation, many enthusiasts prefer a petrol engine’s raw power, sound, and realism.

How do petrol RC cars work?

Here is how they work:

The Basics

Petrol RC cars are miniature vehicles powered by small internal combustion engines that use a mix of petrol (gasoline) and oil. These cars mimic the workings of a full-sized automobile but on a much smaller scale.

Fuel System

Petrol Mixture: Typically, the petrol used for RC cars is mixed with a two-stroke oil. This oil ensures proper lubrication of the engine’s moving parts and helps dissipate heat.
Fuel Tank: The petrol mixture is stored in a small fuel tank, which usually includes a one-way valve to let air in as the fuel goes out, ensuring a consistent flow to the engine.
Carburettor: As the engine runs, the petrol mixture is drawn from the tank into the carburettor, which regulates the amount of fuel and air mixture that enters the engine.

Engine

Internal Combustion: Petrol RC cars employ a two-stroke internal combustion engine. The engine has a single cylinder, and during its operation, it goes through two main cycles: intake/compression and power/exhaust.

In simple terms, the spark plug ignites the fuel-air mixture, causing an explosion that drives the piston. This, in turn, powers the vehicle.

Cooling System: Given the heat produced by these explosions, a cooling system, usually involving cooling fins on the engine and sometimes a fan, ensures that the engine doesn’t overheat.

Drive System

Clutch: Just like in full-sized cars, the engine’s power needs to be transferred to the wheels. A clutch system ensures that when the engine is idling, the car isn’t moving. But as the engine’s RPM rises, the clutch engages and transfers power to the transmission.
Transmission and Differential: The power is then transferred through a gearbox, which controls the speed and direction (forward or reverse). From there, a differential might distribute power to the wheels, allowing them to rotate at different speeds, particularly during turns.

Control System

While the engine and drivetrain get the car moving, controlling its direction, speed, and other operations are handled by the RC system.

Radio Transmitter: The user holds and operates a radio transmitter, sending signals to the car to control its functions.
Receiver: The RC car has a built-in receiver, which interprets the signals from the transmitter and sends commands to various servos.
Servos: These are the small motors or actuators that physically execute the commands. For instance, a servo might be connected to the steering mechanism, allowing the user to control the car’s direction.

Exhaust System

Lastly, just as in real cars, petrol RC cars have an exhaust system to expel the burnt gases from the combustion process. This not only reduces internal pressure but also aids in the pulling of fresh fuel-air mixture into the cylinder.

Can you self-build a petrol RC Car?

Yes. With the right set of skills, tools, and patience, constructing a petrol RC car from scratch or via kits can be an immensely rewarding experience.

Whether you’re an RC enthusiast looking to level up or a newbie willing to dive deep, building a petrol RC car offers a hands-on journey into the fascinating world of automotive mechanics and engineering.

The Basics of Petrol RC Cars

As discussed earlier, Unlike electric-powered cars, petrol RC cars run on a mixture of unleaded petrol and 2-stroke oil. The engine sizes typically range from 23cc to 30cc, although some models have even larger engines.

Components Needed

To build a petrol RC car, you’ll need:

Chassis: The structural framework that holds the car together.
Engine: 2-stroke petrol engines are commonly used. These are available in various sizes and power outputs.
Fuel Tank and Fuel Lines: To store and deliver the petrol mixture to the engine.
Exhaust System: Helps to expel burnt gases and produce that unique roaring sound.
Electronics: Including servos for steering and throttle, a transmitter, and a receiver.
Transmission System: Gears, differentials, and drive shafts to deliver power to the wheels.
Suspension: Shock absorbers and springs to navigate rough terrains.
Tires and Wheels: Specific to the terrain you intend to drive on.
Body Shell: Protects the internal components and gives the car its aesthetic appeal.

Steps to Self-Build

Planning and Design: Decide on the car’s scale, type (on-road or off-road), and budget. Sketch a design if you’re going for a custom build.
Component Acquisition: Source the components either online or from hobby shops. While many opt for kits, experienced hobbyists might choose individual parts for a more tailored experience.
Assembly: Start by setting up the chassis. Attach the engine, followed by the transmission system, electronics, and suspension. Ensure the components fit snugly and are appropriately aligned.
Testing: Before finalizing, test each component individually, especially the electronics. Ensure the servos function correctly and the engine starts without issues.
Tuning: Post-assembly, tuning the engine for optimal performance is crucial. Adjust the carburettor settings, ensuring the right air-fuel mixture for peak performance.
Final Checks: Ensure all nuts, bolts, and screws are tightened. Fill up the fuel tank and perform a test run.

Challenges and Considerations

Skill Requirement: Building a petrol RC car requires a blend of mechanical and electrical knowledge. Familiarity with 2-stroke engines is beneficial.
Tool Availability: Ensure you have the necessary tools such as screwdrivers, pliers, wrenches, and possibly a soldering iron.
Safety: Always work in a well-ventilated area and keep a fire extinguisher nearby. Petrol is flammable, and safety precautions are paramount.
Maintenance: Petrol RC cars require regular maintenance. Cleaning, tuning, and occasional part replacements will ensure longevity.