Breaking in a new nitro engine is necessary to allow the piston and sleeve to develop a precise fit and optimum cylinder sealing. Proper engine break-in is therefore critical to achieving the fastest, most reliable engine performance.
There are many ways on how to break in a nitro RC engine, but this article covers how to break in a nitro RC engine using the Traxxas method. In this article, we will cover how to prep a nitro engine for the first break in and the break in process.
For the purpose of this article, we will be referring to the Traxxas T-Maxx 3.3 as the RC vehicle. Here are some things you will need for breaking in:
- Tuning screwdriver, flat head screwdriver
- A temperature gauge , in order to keep it within 215 to 270 degrees Fahrenheit
Step One: Pre-Inspection
One of the first things to check before breaking in the nitro engine is the fuel door. Many people tend to overlook checking the fuel door, but you should check to ensure that the fuel door seals off properly in order to get the correct pressure for your engine to run correctly.
Check that the O-ring around the neck of the fuel tank is properly compressed for maximum sealing. If your nitro car’s O-ring is not properly tightened, you can simply screw down the screw to make the O-ring tighter.
Next, you will want to check that your motor mount screws are tightly screwed to hold the motor mount to the chassis. It is a good habit to regularly check every screw on your vehicle to make sure that they are tightly screwed in.
Lastly, you would want to check your gear mesh. You want to make sure that when you put your fingers on the little clutch and rock back and forth, you are able to move it due to the right gear mesh.
Step Two: Fuel Up The Fuel Tank
After doing the pre-inspection and making sure that there is a new glow plug in there, it is time to fuel up the fuel tank!
Step Three: Prime The Engine
First, you will want to use a finger to cover the exhaust hole and give your pull starter or EZ starter a couple of turns. You will start noticing that the fuel will start moving up the carburetor.
Some people prefer to loosen their glow plug one half of a turn as the compression on a new vehicle is very high, and they loosen it to make it easier to start the engine. If you do this, remember to tighten the glow plug back to the original tightness once the engine starts running.
It is important to make sure that you are starting your engine at or above room temperature (70°F or 21° C). If the temperature outside is cooler than room temperature, remove all fuel and keep your RC vehicle indoors until you’re ready to start it and then take it outside.
Step Three: Breaking In
Next, turn on the kit and motor. Check that the steering, throttle and brake are working correctly.
You can either choose to run your RC vehicle on an open grass area or a flat concrete area (asphalt etc).
On the first tank, you will want to remove the chassis and use up to a quarter throttle. Accelerate for 2 seconds and then let off and brake. Repeat this until the whole fuel tank is complete, then let it cool for 15 minutes.You will notice that the engine is accelerating sluggishly.
You should look out for thick blue smoke exiting the exhaust outlet. If there is
no smoke, tighten the high-speed needle 1/4 turn by turning the needle counterclockwise.
For tank two, put the chassis back on and use half a throttle. Accelerate for 2 seconds and then let off and brake. Repeat this until the whole fuel tank is complete, then let it cool for 15 minutes.
For tank three, use half a throttle. Accelerate for 3 seconds and then let off and brake. Repeat this until the whole fuel tank is complete. You do not need to let the engine cool down.
Go full throttle on tank four. Accelerate for 3 seconds and then let off and brake. Repeat this until the whole fuel tank is complete. You do not need to let the engine cool down. If you are running a 2 speed RC vehicle, do not allow shifts to high gear (some RC vehicles are factory pre-set to shift pretty early).
Go full throttle on tank five. Accelerate for 5 seconds by accelerating over 3 second count and holding it for 2 seconds. You do not need to let the engine cool down. Repeat this until the whole fuel tank is complete.
After the fifth tank of fuel, the engine break-in process should be complete.
Other Tips On How To Break In A Nitro RC Engine
- Don’t forget to use your temperature gauge to monitor the engine temperature while breaking in your nitro RC engine. It is critical to get your engine up to at least 215 – 230 degrees Fahrenheit and sustain it throughout the break in process in order for the sleeve and piston to expand. If you are breaking in your engine during a cooler temperature, you should wrap a sock or something similar around the cooling fans to increase the heat.
To properly use a temperature gauge, you want to place the temperature gauge right over the top of the glow plug and cooling head.
- Always make sure that there is plenty of smoke coming out of the exhaust when breaking in. A trail of smoke means that the engine is getting proper lubrication.
- Do not run the tank empty when breaking in. All nitro vehicles tend to lean out as the tank empties because there isn’t as much pressure forcing the fuel into the carburetor when there is less fuel in the tank. Hence, you should keep the tank full and work down to half a tank and then refuel. If you need to run a full tank before letting it cool, you should first run it to half tank, refuel, and then run it back down to half again. Doing so will ensure that the engine is receiving the maximum amount of lubrication possible.
- During the break-in period, your engine may appear to malfunction with symptoms such as stalling, inconsistent performance, and fouled glow plugs. This is normal and are just some “break in pains” that new engines have to go through.
- The entire break in process should take you around 3 hours.
With this guide, you should now know how to break in a nitro RC engine using the Traxxas method. Leave us a comment or question in the comment box below!