I need to brake in my new Thunder Tiger engine, What is the best way to brake it in? This is my first plane I want to make sure I am doing things right.

Following the instructions that came with the engine is always the best way to break-in an engine.

Ken

I agree with RCKen. Make sure you have good, clean fuel and you are not in a very dirty environment. Make every precaution including safety. Do not get lazy with anything, a very well broken in engine will last you a very long time. It will also show you any problems you may have before you put the plane in the air. Check your fuel lines for any leaks, and most of all (RCKen, feel free to correct me anytime), check everything several times and to make sure you have smoke coming out of your muffler. No smoke can mean it is too lean...this is not good.

There is a long and detailed thread on breaking in ABC/ABN engines by Dar on the engine forum. You can use the search tool to find it. His advice seems to be highly regarded.

Dar Zeelon is on the MVVS engine section, his instructions are the best. I always use his method and have never gone wrong......

Another place for reliable information is Jett Engineering. They have a good break-in schedule there as well.

Break in is a very touchy subject (for an ABx anyway) and following the manufacturer's instructions is the best way like RCKen said. But if you don't have the instructions or they're a bit vague (and some are dreadful) then I can only pass on what I found by doing some experimenting on my own new engines. Running too rich (4 stroking) only runs in the rod bushes and didn't do anything for the piston although the liner began to get a polish. Running much leaner (as Dar suggests, 500 to 800 below peak revs) caused some damage to the piston with localised overheating but nothing too serious although it lost all the pinch. However, I'd prefer to have no damage at all so after that experiment I've always given them a first run just in a 4 stroke then gradually leaned them out over several tanks to slowly build up temperature.

suggestion 1) Mount it on a test stand - do not break it in on the airplane. Ensure the fuel system is clean.

suggestion 2) use the fuel you will use for flying it. Nothing special. No real need to add oil or anything.

suggestion 3) Select a prop 1" diameter smaller than you will be flying with. (if the engine is a TT46, use a 9x6 for break-in, first flights with a 10x6). Your first 3 or 4 break-in runs should be done using the lighter-load prop.

Take the time to become familiar with the engine while it is on the test stand.

Above all, be careful.

Follow the links and suggestions others have posted.

But do not get caught up in too many of the details. Break in is not THAT complex.

Your best bet it to find an experienced local modeler who can assist you and guide you through the process.

Bob

As long as it will idle and pick up from the idle, there is no need to bench run this engine.
If if runs on the ground it will run even better (unloaded) in the air.

tune it so it just breaks into a clean run and enjoy yourself flying it.

Hi!
Running in an engine is not Rocket science...
But what you must know is the following...

1. Is it a ringed engine.
2. Is it an ABC, AAC, or ABN engine (piston i A=Alu, liner in B=Brass which is C=Chromed ...or N=Nickel plated)

If it is Nr 1...it has to be run in rather slowly the first tanks (3-7)so that the steel piston ring gets seated in the steel cylinder. That means running the engine under light load, rich, not laboring it with a big diameter prop. For a .40 seize engine this usually means using a 9x6, 9x7, 10x6, 11x4 or 11x5 prop. Running in is best done in the bench the first couple of tanks ...buyt could also be done in the air by mounting th engine in the airplane and fly ...as long as the engine gets an adequat (rich enough) carb setting.


If it is Nr 2...it has to be run in under fairly high rpm so that the temperatur in the combustion chamber expands the cylinder walls away from the piston. The cylinder walls are converging at the top and this makes the piston touch the cylinder walls at the top of the stroke. You can feel the pinch when turn the engine over...
This way the piston gets seated in the cylinder. What prop to use is the prop you intend to run the engine with...for a .40 seize engine this usually means a 9x6, 9x7, 10x6, 11x4 or a 11x5 prop.
Engines could be run in the air or in bench...doesn't matter... as long as you run them fairly rich the first couple of tanks (3-7).


The only thing that you most avoid is to run in the engine in the airplane with the airplane sitting on the ground ! That's a NO NO!
Why? Because of dust and dirt particles that the engine inhales which fast destroys the piston to cylinder fit!
Remember...it's the piston to cylinder fit that is the most vital thing in our engines... lose that fit and you loose power and throtteling ability!


What fuel you use isn't vital as long as you follow some simple rules.
And they are...
1. Do not use too much nitro in European made engines as they are made with higher compression raitos then most Chinese or Japanese engines. 0-5% nitro is all that is needed to have a good running engine with perfect throtteling.

2. Do not use more that 15% nitro in most other engines.

3. If it's syntetics or Castor oil based fuel doesn't matter....whats matter is the above nr 1 and 2!!!!

I personaly use 15% all syntetic oil and 5% nitro for all my engines be it 4 strokes or 2 stokes since 6 years back with perfect results. This is for both for running in and for general sport flying. I have been flying for 31 years and before I started using all syntetic oils, Castor oil was the oil I used and what most fellows over here in Sweden and Europe used. Nowadays I think very few uses 20% Castor oil as most flyers prefere 10-15% all syntetic oil.