Being around RC cars almost all my life, I had developed a special inclination towards their working mechanics trying to make sure I stay up to date.
RC cars work on electric, nitro, and gasoline engines as sources of their energy. The nitro engine RC cars are the most powerful amongst the three. Electric models are better in speed and efficiency. Gasoline-fueled cars utilize a mixture of oil and gasoline as fuel.
This experience and passion have taught me that the fuel RCs use makes a big difference in the way they run and function.
On a personal level, I feel that nitro models are the most powerful and fun to work with. Let us take a look at these models in detail.
Electric Vs Nitro Vs Gasoline
| Kind of RC | Electric | Nitro | Gasoline |
| Fuel Used | Rechargeable nickel-metal hydride, nickel-cadmium, or lithium polymer cells | A blend of nitromethane, methanol, and oil is used | Utilize a mixture of oil and gasoline. |
| Types | Two types of electric motors- brushed and brushless. | One Type | One Type |
| Speed | Brushless is fastest compared to any other type. | Slower than some of the brushless electric models. | Average speed |
| Battery Life | Brushless has a better battery performance than brushed engines | No battery is needed. Runs on fuel | They run on gas, once it’s over you need to fill gas again |
Electric Type
Compact yet powerful electric motors are used to fire up electric cars. These electric motors have rechargeable nickel-metal hydride, nickel-cadmium, or lithium polymer cells.
Apart from that, you will see two types of electric motors- brushed and brushless. Brushless motors are costly yet more powerful and efficient.
Nitro Type
While glow plug engines are used in fuel-powered motor modals. A blend of nitromethane, methanol, and oil is used to fuel the small and compact internal combustion engines.
Gasoline Type
Large models of these cars have been manufactured lately that is charged up by compact gasoline engines. These fall pretty close to string trimmer motors that utilize a mixture of oil and gasoline.
Electric Models
Compact yet powerful electric motors are used to fire up electric cars. These electric motors have rechargeable nickel-metal hydride, nickel-cadmium, or lithium polymer cells.
Apart from that, you will see two types of electric motors- brushed and brushless. Brushless motors are costly yet more powerful and efficient. Read below to find out how these work.
Brushed DC motors
First, you should know that a motor converts any kind of energy into motion. An electric motor hence converts electricity to motion. This is done via two magnets.
One of the magnets is created by tightly winding a wire around a ferrite core through which electricity is passed.
The second magnetic field is created through the current, which passes through the wire. The two magnetic fields repel each other, hence rotating the motor around an axle.
Structure
The brushed motor contains four salient components- the stationary magnet- permanent or electromagnet, rotor, commutator, and brushes. The rotor, which is the ferrous metal with the wire is connected to one of the brushes.
When current is passed, the magnetic fields of the rotor and the stationary magnet interact to create a force of motion.
Working
A loophole with using regular wires for rotor winding connections is that once the rotor has reached a certain angle of rotation, it would reverse in direction, and hence the rotator would just keep changing directions.
Hence, we use the commutator that is essentially just a copper sleeve circumscribing the axle, which divides the structure electrically and physically.
So when the power is applied and the current is passed, the commutator keeps connecting and disconnecting these two segments, alternatively giving power to both.
This reverses the polarity of the magnets, which in turn allows the motor to run smoothly.
Here are a few pros and cons of brushed motors over brushless ones.
Pros
- Low cost of construction
- Can be repaired easily
- You don’t need a controller for constant speed
- Great in case of environments that require extreme operations
- They are noiseless and can be run on all kinds of RC tracks
- Easy to maneuver and hence great for beginners.
Cons
- Battery dependent. The power gets discharged fast and easily and needs time to recharge.
- They are slower than brushless and nitro engines.
- The vent holes present are susceptible to dust and water, which might harm the device.
Brushless Motors
The permanent magnet in these motors obviates the need for brushes. The basic structure is nearly the same. It consists of a permanent magnet rotor and a stationary magnet with a coil wound around it.
An added element is the Hall Effect sensors, which are used to create feedback signals. These feedback signals navigate semiconductor switching devices.
Essentially brushless motors are 180 degrees flip of brushed motors. The rotor has permanent magnets and the stationary magnets have electromagnets.
The electromagnets are charged by a computer which helps the rotor rotate fully by 360 degrees.
Pros and cons of brushless motors over brushed electric motors are:
Pros
- They are about 80-90% more efficient
- They can work very well with high operating speeds
- There is no wear and tear caused due to brush sparking
- They have better battery performance.
- The heat dissipation gives them an upper hand which protects them from residue and debris.
- They have a small and compact size
- Brushless motors have a quicker response and are easier to maintain.
- You can control the speed with ease and they can self-start
Cons
- They are costlier than brushed engines due to the absence of brushes and longer-lasting LIPO batteries along with other upgraded pieces of equipment.
- They are quite fast and hence might be difficult to control and maneuver.
| Image | Name | Description | Price | Prime | Buy |
|---|---|---|---|---|---|
 Top | Losi RC Truck SCT | Losi RC Truck SCT Brushed RTR (Ready-to- Run), Black (LOS03022T2) | PrimeEligible | Buy Now | |
Top | Typhon 4X4 V3 | ARRMA 1/8 Typhon 4X4 V3 3S BLX Brushless Buggy RC Truck RTR (Transmitter and Receiver Included, Batteries and Charger Required), Red, ARA4306V3 | PrimeEligible | Buy Now | |
 | Losi Super Rock Rey | Losi RC Truck 1/6 Super Rock Rey 4WD Brushless Rock Racer RTR (Ready-to-Run) with AVC, Baja Designs, LOS05016T1 | PrimeEligible | Buy Now | |
 | Traxxas Rustler 4x4 VXL | Traxxas 67076-4 Rustler 4x4 VXL Off Road Electric Remote Control RC Car with Remote Control for Adults and Kids, Red | Prime | Buy Now | |
 | Traxxas Bandit | Traxxas Bandit: 1/10 Scale 2WD Off-Road Buggy with TQ 2.4ghz Radio System, Red | Prime | Buy Now | |
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Nitro
Glow plug engines are used in fuel-powered motor modals. A blend of nitromethane, methanol, and oil is used to fuel the small and compact internal combustion engines. These are called nitro cars.
When the fuel is ignited, the impact of the exploded fuel pushes down the piston which gives power to the engine. As the piston goes down, the crankshaft rotates which shuts the carburetor slot.
Since the piston is putting pressure on the fuel-air mixture inside the crankcases, it gets compressed. As the piston drops, the exhaust port gets exposed which lets the exhaust gases out of the cylinder.
Now the intake port is opened and the compressed fuel mixture enters the cylinder via the transfer ports.
These intake gases will force all exhaust fumes out through the exhaust. Once the piston reaches the bottom of its stroke, the slot under the carburetor will open.
This will, in turn, lead to more air mixture and fuel being pulled through by the vacuum.
Once the piston begins to go back up and the vacuum of the crankcase releases the fresh fuel to the bottom and the transfer of fuel into the upper cylinder slows down.
This new mixture is compressed like before as the piston covers the intake ports. Any leftover exhaust gas leaves the cylinder. At times a little fuel-air mixture is thrown out as well.
However when the exhaust closes the new air mixture is compressed as a result of which the cylinder head temperature rises and the glow plug renders fuel ignition. This cycle is repeated.
Here are a few pros and cons of nitro motors to help you draw a comparison between the three discussed motor types.
Pros
- It doesn’t run out of battery. Fuel is the only source required to keep it running.
- They’re faster than brushed electric motors and a few brushless ones.
- They are water-resistant in comparison to electric ones.
Cons
- They are noisy compared to electric engines
- High maintenance
- Fuel is costly and hence operational costs are slightly pricey
- Most nitro motors don’t have a reverse option
- They produce fumes that can be harmful
| Image | Title | Price | Prime | Buy |
|---|---|---|---|---|
Top | TEAM LOSI RACING RC Car 1/8 8IGHT-X 4WD Nitro Buggy Elite Race Kit, TLR04010 | Prime | Buy Now | |
Top
Top | Dodge SRT Demon 1:8 Scale Inferno GT2 Race Spec Nitro RC Car | Prime | Buy Now | |
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Top | QSs-Ⓡ RC Car 4Wd 1:10 on Road Racing Two Speed Drift Vehicle Toys 4X4 Nitro Gas Power High Speed Hobby Remote Control Car | Prime | Buy Now | |
 | Losi 1/8 8IGHT-T 4WD Nitro RC Truggy RTR | Prime | Buy Now |
Gasoline
Large models of these cars have been manufactured lately that is charged up by compact gasoline engines. These fall pretty close to string trimmer motors that utilize a mixture of oil and gasoline.
Gasoline engines are 4 stroke engines that comprise four elements- Air, Fuel, Compression, and Spark.
Air and Fuel are input into the carburetor which mix the two for combustion. This fuel and air mixture enters the combustion chamber through the intake valve.
As the mixture enters the cylinder bore, the piston pushes downwards.
When the piston reaches the bottom dead center, the capacity of the fuel-air mixture in the cylinder reaches its peak.
The intake valves close again and the piston springs back up to its original position and the mixture gets compressed between the head of the cylinder and the piston. This is also referred to as the compression stroke.
Then comes the power stroke. Since the piston is at the top dead center, it has the potential to ignite the fuel to provide the maximum power to the motor.
This stroke creates a high voltage, which is discharged using a spark plug, into the combustion chamber.
The heat ignites the gases, which release highly heated and expanding gases that push the piston down to the cylinder bore.
In the last stroke, the piston is at the bottom again and all combustion gases are released through it when the piston moves up. Once all gases are out, the exhaust valves shut and the piston is back to the top.
The entire 4-stroke engine cycle repeats itself. Power is created in only one of the four strokes however, the crankshafts fully rotate twice. A small engine flywheel keeps the machine functioning.
Final Thoughts on What Do RC Cars Run On
Choosing the right power source for your RC car can be challenging if you have half-knowledge of the subject. With this extensive guide, you will be able to make an informed decision.
Whichever option you go for, keep the power of the vehicle and the level of the user controlling the car in mind. All three engines work well if they are taken care of.
Sources
https://www.diodes.com/design/support/technical-articles/driving-brushed-dc-motors/
http://www.rcracer.com/2009/09/how-nitro-engines-work-63/
http://buildipedia.com/aec-pros/design-news/the-brushless-dc-motor-and-its-use-in-electric-cars
