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Old 07-08-2007, 11:05 PM   #1
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Default How To Break In ??????

Just got my new LRP Team Truck engine and and don't how to break it in.
i'v heard of the heat cycle break in but have no idea how to do it.
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Old 07-09-2007, 08:10 AM   #2
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try posting in an already existing forum you get answers much quicker
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Old 07-09-2007, 08:46 AM   #3
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Engine Tuning - New Engines
How to Break In your New Engine, by Ron Paris

Everything that’s needed to ensure your engine’s long life is contained in its carburetor. Most carbs have three adjustments that you’ll need to familiarize yourself with: The first, and most important, is the high-speed needle setting. This needle valve controls the mixture of fuel and air that enters the engine’s combustion chamber during high-rpm running. More fuel in this mixture causes a “rich” condition, while less fuel (more air) causes a “lean” condition. A richer high-speed needle setting will actually help keep the engine running cooler as it reduces rpm, and because there is more fuel passing through the combustion chamber, a bit of “liquid cooling” actually takes place. A leaner setting will allow the engine to achieve higher rpm, but will also cause it to run hotter.

A properly set high-speed needle will provide a compromise between a cool temperature and high rpm. Needless to say extremes in either direction aren’t good, but nobody ever blew up their engine by running it too rich!
Many racing engines also have a secondary needle-valve adjustment that is used to control the engine’s low-speed fuel/air mixture. This needle is used to adjust the way the engine makes the transition from low to high rpm. It also helps control the fuel mixture when the engine is idling. A low-speed needle setting that is rich will reduce throttle response at low rpm, and may make the car sluggish coming out of tight turns. A leaner setting will allow the engine to make more power during low rpm operation.
Many modern sport-type nitro engines have eliminated the low-speed needle entirely. While this doesn’t allow for the highest level of tuning for the experience racer, having one fewer needle to fuss with does make these engines much more user-friendly to the beginner, who only need set the high-speed needle.
Finally, there’s the idle-stop screw. Basically, this screw is used to keep the carb’s slide or barrel from becoming totally closed (which would stop the engine from running). A small opening of the carb allows just enough air and fuel to mix and keep the engine running. Setting the idle is usually done after you’ve properly set both the high- and low-speed needles.

Before you even place your nitro car on a starter box or yank its pull-starter, read the instruction manual that came with your engine or car kit. Most nitro kits’ manuals have a section that will tell you approximately where the carburetor’s needle settings should be for initial start up. We have found that higher-end (more expensive) engines tend to follow the instruction’s settings more closely, which means that when the manual says to set the high-end needle at three turns out from closed, this is almost exactly where the engine will run best for break-in.
For sport-type engines, the needle position that allows the engine to fire and run may be quite different from what’s recommended in the manual. In our experience, if a sport engine won’t fire, leaning the high-speed needle in small increments will get it going. Once the engine fires and runs consistently, we will usually richen the needle back to where the instructions recommend. Never run a new engine, or even an older one, too lean!

We know that you want to go out and do some hot laps the instant your new engine fires to life, but don’t! The first few runs of your new engine are critical. Once your engine starts, place the car on a stand so that its wheels can’t touch the ground. Let the engine idle at low rpm for a few minutes (two or three minutes will do), then shut the engine down and let it cool.
During this procedure, it’s also important that the piston not be at the top of the cylinder while the engine is cooling. Part of what’s taking place during break-in is that the engine’s mating parts are being heat-cycled. They’re expanding when the engine is hot and contracting when it cools. Heat cycling stabilizes the metal and allows mating parts to fit better against each other. Keeping the piston out of the upper portion of the cylinder (which is smaller in diameter than the lower portion in order to create a better seal during combustion) will allow the cylinder to properly contract as it cools—without interference from the piston. To figure out where the piston is in relation to the cylinder, just turn the flywheel. It will become difficult to turn when the piston is at the top of the cylinder, where the fit between the piston and cylinder is its tightest. Just turn the flywheel until the piston is in the middle of its “easy turning” part.
Now you’re ready to lay down some horsepower, right? Wrong! Repeat the above steps three or four more times.

After you’ve heat-cycled your engine, you can finally put it on the track. But don’t get too excited yet. You must run it with a very rich high-speed needle setting. Some engine experts recommend that, during break-in, the engine be set rich enough so that it will actually four-cycle instead of two (our nitro engines are two-cycle, which means that the fuel/air mixture is ignited once for every two strokes of the piston). Four cycling means that the engine is actually only firing one time for every four strokes of the piston. In this condition, all of the unburned fuel passing through the combustion chamber takes heat (and any tiny metal particles created during the breaking-in process) right out to the exhaust pipe!
Do you really need to run the engine this rich? Well, the experts know their stuff, but we have broken in dozens of new engines without actually allowing them to four stroke. Whether or not you four-stroke your engine during break-in is entirely up to you—just make absolutely certain that the high-speed needle is set very rich: lots of blue smoke should be coming from the exhaust, and the engine should sound “blubbery.”
During this procedure, it’s vital that you avoid prolonged use of full throttle, which could strain the engine. You should instead “blip” the throttle as you drive the car to avoid spending too much time in one particular rpm range.
Run the engine using these settings for three or four tank-fulls of fuel, allowing the engine to cool in between runs.

Once you’ve put about six to eight tanks of fuel through the engine (as outlined above), it’s time to begin leaning the high-speed needle and making some power! Begin by leaning the high-speed needle (by turning it inward, or clockwise) by about one-hour (if you imagine the needle as a clock-face, one full turn of the needle would equal 12 hours). Run the car for a minute or so, then bring it back in and lean the needle by another one hour increment. Repeat this process until the engine begins to achieve good rpm, but it shouldn’t be allowed to “scream” quite yet. The engine should still be creating lots of blue smoke from its exhaust.
Before you achieve that screaming race setting, we recommend that you run your engine for a few more tank-fulls in this “almost race” setting. Once you get the needle set to where your engine is making good rpm, richen it (by turning the needle counter-clockwise) by about a quarter of a turn. This is your final setting.

Once you’ve found a good setting for the high-speed needle that allows the engine to make good power yet still push plenty of blue smoke from the exhaust (especially when the car exits a turn), it’s time to set the low-end needle and the idle-stop screw.
Most engine manufacturers recommend a specific setting for the idle-stop screw, and they’re usually well within the ballpark. For now, set the idle-stop screw so that the engine will idle at a moderate rpm without stalling.
Bring the engine up to operating temperature by driving it for a few minutes. Now stop the car and listen to the engine’s idle speed. If the engine idles fast but then slows down in just a few seconds, the low-speed needle is probably set too rich. Lean the low-speed needle (by turning it clockwise in one-hour increments) until, after running a few more laps, the idle stays high for about twenty seconds or so when you stop the car. Once you’ve done this, use the idle-stop screw to make the final adjustment of the idle speed.
For sport engines which lack a low-speed needle, the idle-stop screw is the only method of adjusting the engine’s idle speed. For these engines, simply turn the idle-screw clockwise to increase idle speed, and counterclockwise to reduce the idle speed.
Setting your engine’s idle speed isn’t a contest to see how low you can get it without stalling the engine! Your goal when setting the idle should be to allow the engine to run at moderate rpm without the clutch being engaged whatsoever. Your car should be able to sit at a standstill when idling. If you have to hold the brake, the idle is too high. If you have to blip the throttle to prevent stalling the engine, the idle is too low.

Nitro powered R/C vehicles can be tons of fun, or they can cause tons of frustration. The difference between success or failure lies with the break-in process. If you follow these steps, have patience, and use your noggin, you’re assured of success. Rushing through the break-in procedure or worse, forgetting it altogether, is a recipe for disaster.

Tuning your engine is the hardest part of nitro racing. But once you’ve learned how the carburetor works, and which screw does what, it will all become second nature. So when you’re running your car, you’ll always know exactly what to adjust to gain the highest level of performance possible.

1. Rich is good. Blue smoke should always be coming from the exhaust.
2. Always set the high-speed needle first
3. Never try to tune a cold engine—wait for it to get up to operating temperature.
4. Always begin your engine tuning from a rich high-speed needle setting. Never start out with a lean setting.
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Old 07-09-2007, 01:05 PM   #4
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You may want to look at this website:

It is a little more up to date. I have recently done it this way with very good results.
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Old 10-08-2007, 03:45 PM   #5
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Originally Posted by Nickmind View Post
You may want to look at this website:

It is a little more up to date. I have recently done it this way with very good results.
I did the Idle break in methed I ran 3 tanks first got the temp about 230 and then on the next 3 tanks i got the motor 240 and then the next 3 tanks i put the car on the ground and ran about half throttle watch temp mine never got over 270 on my Losi 427
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Old 10-08-2007, 09:19 PM   #6
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Reccomended Engine Break In

Remember to always run your Go Engine in a well ventilated space and also remember model engines and model fuel are not toys and should not be treated as such.

The Following steps are what is reccomended for a proper engine break in. A proper engine break in will not only increase the performance of the engine it will also greatly increase the longevity of your Go Tech engine. During the break in period the engine is under the most stress. Because of the tight tolerances of the piston and sleeve (which is vital to a performance engine) the connecting rod will see the most abuse during break in. To minimize this abuse it is important to keep the engine running in its optimal temperature range, running too cold is especially hard on the connecting rod. The ideal temperature for break in is between 210-240 degrees, we recommend purchasing a temperature gun and keeping a close watch on the temperature during break in.

The following break in procedure will require 7 to 8 tanks of fuel. We recomend that you use a fuel with a high oil content and low nitro content such as sport model fuel and not racing fuel. Always allow the engine to cool down to ambient temperature inbetween each step before continuing to the next step. Always place the piston in Bottom Dead Center before it has a chance to cool, you will need to do this everytime you use your engine. If you follow these steps you should have a long lasting engine.

The first step is to wrap the engines cooling head up in aluminum foil. this will help it achieve optimal tempature fast and help insure the engine is not running too cool. It will also force you to run a richer needle setting to keep the engine in the temperature range. We also reccomend using a heat gun of hair dryer to get the engines temperature up above 160 degrees before trying to turn over the engine. Allow the engine to cool and remember to place the engine at bottom dead center
For the first 2 tanks of fuel you should only let the engine idle (do not rev at all.) make sure the engine is around 210-240 degrees monitor it closely and use the needle valve to control temperature.
For the third tank of fuel you should repeat the steps and pulse the throttle to 25%, remember do not hold it open just slow open then close no more than 25%. If you have a computer radio you can use the servo endpoints to accomplish this and it will make it much easier for you.
For the fourth tank of fuel repeat step three but this time you can open the engine up to 50%. You should no longer need the alumn. foil wrapped around the cooling head and remember to keep a close watch on temperature, at 50% throttle it will be very easy to over heat the engine. Remember to control the temperature with your needle valves.
Tank five is a repeat of step four but this time open the throttle up 75%. Remember that you want to pulse the throttle and should never have the throttle open for longer than 1 second.
Tank six repeat step five but this time open the throttle up 100%. Remember that you want to pulse the throttle and should never have the throttle open for longer than 1 second. At this stage it is extremely important to watch temperatures as the engine can over heat very quickly and unexpectedly. In order to maintain temperature at this stage the engine should be running extremely rich.
Now your ready to take the car out and tune for performance your engine should be ready to go. Don't overdue it too much for the next 2 tanks but you should be able to drive around the track at a good speed but not race speed.
Get ready to go out there and win.
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Old 10-09-2007, 12:05 PM   #7
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holy crap!!!! 7 -8 tanks of fuel???? wow... . mine was broken in, in 3 tanks. first tank i let it idle, second tank i ran it around for a bit not too much, 3rd tank i was giving it way more throttle.. pretty much running it at WOT.
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Old 10-09-2007, 01:05 PM   #8
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Actually it 'PROBABLY' wasn't 'broken-in' in 3 tanks. You may have thought it was, but there is an extremely high probability that it wasn't.

Unless your tank holds 4~500cc's of fuel, that is...

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Old 10-09-2007, 01:07 PM   #9
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BTW ~ +1 on the heat cycling methodology...

Works great on motorcycle racing engines too!

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Old 10-09-2007, 01:07 PM   #10
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Originally Posted by savage.25 View Post
holy crap!!!! 7 -8 tanks of fuel???? wow... . mine was broken in, in 3 tanks. first tank i let it idle, second tank i ran it around for a bit not too much, 3rd tank i was giving it way more throttle.. pretty much running it at WOT.
there is no way you got a motor properly broken in in 3 tanks.
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Old 10-09-2007, 01:10 PM   #11
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I agree with rabidsquirrel...there's no way an engine is fully broken in and ready to race after 3 tanks. My VSpec wasn't even fully broken in after it's first full race day. I thought it was but didn't realize I was wrong until I felt heavier top end and was getting better runtime.
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Old 10-09-2007, 02:44 PM   #12
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Most engines, when broken in properly won't be fully broken in for at least a gallon. Just remember to idle the first tank, ALWAYS heat it up to around 200 degrees with a hair dryer/ heat gun, and drive around slowly for about the first quart, slowly turning in the needles and driving faster until it runs at operating temp without something insulating the head. Heat it up until all metal to metal pinch is gone and it should last you 10 gallons!
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