Running-In your new RC Car Engine

12 Hillside Court, Barbot Hall Industrial Estate, Rotherham, South Yorkshire. S61 4RP Tel: 01709 377250

Each day we get asked about the 'running-in' of a new engine.
Is it absolutely necessary? - Do I really need to do it? - What happens if I don't?
Let's try and answer these questions for you..
Q: Is it absolutely necessary?

A new engine incorrectly run-in or not run-in at all will appear to run well but....not for long
Incorrect or no run-in at all will seriously shorten the life of your engine.
Q:Do I really need to do it?

Bearing in mind the answer to the question above a correctly run-in engine will provide possibly years of superb performance.Top speeds, responsiveness, good fuel economy and reliability are the rewards of a well run-in engine
Q:What happens if I don't?
A: Your engine's life will be shortened dramatically.

You may face erratic starting problems, high fuel consumption and lack of performance if you thrash your engine from new. Ultimately ending in a new engine being required.
Q: How do I run it in?
A: We consider a 10% to 16% nitro mix

to be ideal for the running in period. Straight from the box, your new car's engine will be set to run 'rich'. That's to say, the carburettor settings will be set to allow higher than normal volumes of fuel through to the cylinder.The reason for this is to ensure the engine runs cool and receives sufficient oil to 'seat' the new engine components.

A common problem when running in a new engine is the frustration of the engine continually cutting out. This is normal. The engine is having to cope with more fuel than is normal and so is to be expected. Persevere. Also, you may suffer from another common new car problem - tight engine! When starting a new engine, it can be beneficial to 'crack open' (slacken) the glow plug slightly to allow some of the compression out. Then, once the engine has been started, nip the glowplug back up. If you hear the engine slowing, apply a little more throttle. Take care not to 'blip' the throttle too much because this can have a tendency to stall a rich engine also. Keep the engine out of its upper throttle range though.

You will find that after a couple of tanks that the engine will run more readily without cutting out all of the time. It is advisable to have to hand at least one spare glow plug as the running in process can tend to foul the plugs and you may need to change it at least once. Commonly known as 'break-in pains', the symptoms of a rich engine can make you wonder if it will ever get better. Be patient and persevere, the benefits will far outweigh the teething problems. Don't take any notice of your mates who tell you not to bother. "It'll be fine, I didn't run mine in". It's not their engine. It's yours and it cost you a lot of money so do it right. Consider your engine 'broken-in' after at least 6-10 tanks of fuel and not before. In actual fact, the more tanks you put through the engine during the break in period, the better. Try to ensure that you run your car in on a smooth clean surface (not off-road) as dusty conditions may cause the engine to run unnaturally hot. Also, try to avoid breaking-in the engine on very hot or humid days.
It is advisable to run the car in without the bodyshell although not essential as you need as much airflow around a new engine as you can get.

Start your engine, drive the car slowly around to let the engine heat up. Ease the throttle on and off slowly. Try to keep the car moving so as to ensure good airflow around the cylinder head. The idle speed should be set as low as possible to keep the engine running when the car is stopped.
Remember, always run the engine with a clean and oiled air filter (please use proper filter oil).

Finally, it is important to understand that part of the breaking in process is 'heat cycling' the engine. Don't let these terms frighten you, it simply means that when running in your rc car, please allow the engine to cool back to cold between each tank of fuel.
By now you should realise that it's practically impossible to run a car in successfully in one day. It's likely to take a couple of days at the very least.....patience brings rewards! Basically speaking - That's it - how to run-in your engine!