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Old 05-11-2008, 10:05 PM
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Originally Posted by rossoh10 View Post
This is the method I used for my last engine and it is the only break in procedure I will use for now on.I have tried several methods including the heat cycle and I like this the best. Dont knock it until you try.

Install the new engine into your chassis complete with clutch and ready to go as if you were going to race. Take a screwdriver, glow igniter, starter box, and a full bottle of fuel to a remote area where you won't annoy anyone with a running engine. Start your engine and allow it to warm up with several short throttle “blips”. Once your engine has some temperature in it you can begin the break-in process. Start by opening the top end needle 1 full turn. Open the carburetor to full throttle and hold it there. Open the top end needle until the engine flames out. From here, close the top end needle turn and restart the engine again running it at full throttle. Run the engine full throttle for 3 tanks and shut the engine down.
Allow the engine to cool for 15-30 minutes. Once the engine has cooled down, run through the same process again for two additional tanks. On the third tank close the top end needle by of a turn. Instead of holding the engine at full throttle, start using the throttle by doing 2-3 second bursts of full throttle. Once you have done this for of the tank close the top end needle another of a turn and continue throttling the engine. Continue closing the top end needle turn per every tank of fuel. Do this until you have run a grand total of 8 tanks through your engine and then shut the engine down.
Allow the engine to cool for 15-30 minutes and then you are ready to hit the race track. Drive two tanks rich around the track slowly closing the top end needle sneaking up on that perfect mixture. At the end of the second tank your engine should be tuned to race speed. This will give you a total of 10 tanks of fuel through your engine before you really start to lean the mixture for ultimate power.
The reasoning behind this break-in procedure is that there is always a large volume of fuel flowing through the engine. Large volume of fuel means plenty of oil and lubrication for the break in process. This also helps flush out any burrs or small pieces of material that may have been left over from the manufacturing of the engine. Also, the engine has a load placed on it by trying to cycle all of the fuel through it – somewhat similar to the load that you will put on it out on the track when you try to power your car around the track. Last, the engine is broke in with rpm – if you break the engine in at idle then you will not be seating the piston, sleeve, and connecting rod at anywhere near the rpm that it will have to be ready for out on the race track.
This is the procedure that I have used with good success over the years of nitro racing. When I've hurried the break-in process I have had some engines last 30 minutes to 4 hours of racing. When I've taken my time and run through this process I've run engines as long as 16 hours of racing!! Yep, same piston and sleeve!!!! Be patient and have fun!!
Good Luck!!
Josh Cyrul

This is very similar to how I break in motors, and have not had one problem in hundreds of motors for myself as well as customers.

Mount the engine in the car as you normally would.
Get the engine started, and let it idle for 30 seconds to build up some heat.
Slowly increase throttle as you richen up the top end needle. Leave the ignitor on the car and keep going until you achive full throttle and are so rich the engine will barely run.

Run 1 tank like that and let it cool off.

Start engine again and run 5-6 more tanksin that manner. You will notice you HAVE to lean the mixture just to keep the engine running. You can remove the ignitor after the 3rd or 4th tank and lean the engine a bit to compensate. Let the engine cool off again.

After that, fire the car and tune it so you can slowly start driving it around, keep the temp around 130, and keep full throttle blasts to a minimum of a second or two.

Over 3-4 more tanks, gradually get the car up to 180. Let the car cool back off fully once or twice during these tanks.

After that put the car on the track and adjust as necessary. Put in a new glow plug for this step.

I've used this method on everything from entry level engines, to full race engines and have got well above average life out of everything.

Best of all this takes about an hour.

Last edited by largeorangefont; 05-12-2008 at 01:14 AM.
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