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Break-in procedures
Have you guys read up on the "team break-in" procedure on the RB concepts website ?? They have this method that you run your engine at WOT ( wide open throttle ) at 70,80,90 % rich settings. Anybody try this yet. I know a guy that is sponsored by RB and he's gonna break in my motor tommorrow this way. He's broken-in alot of motors this way with great success. I'll let you know what happens.
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Let's explain why you break in a motor, then you'll understand the rational. When you receive a new motor, the parts that make it up are fresh from the CNC or mold process. The tollerances are good, but they aren't great since they are now mated up against a piece that has been cut at a different time and different piece. Because good compression is caused by making sure the piston is tight, a lot of times the cuts are done so that the parts fit real tight. Friction causes wear and every motor will have wear over time. The idea is to use this wear to, in a sense, grind away the imperfections between the mated parts so they wear in a certain pattern that makes the tolerances even better. Once a motor is run for a while the wear loosens the tightness and "breaks-in" a motor. Since a motor is at its least optimum "fit" in the beginning, you want to slowly ease in to this. After all, you're wearing away metal on metal. If you do it too fast, you'll rush the motor through this step and introduce much higher heat, expanding the metal and introducing all sorts of accelerated wear. If you're not tuned right, it could be really bad. Go slow and control this wear process. Motors don't know what brand they are and physics don't either. The same principles apply to all motors. Big 1:1 car motors, motorcycle motors, etc. Why do you think in your normal car your manual says take the first few thousand miles easy. If its not required, the factory does it for you, either way take it slow.
Finally, I'm running a RB motor I got from Chris Tosolini. He's one of the best in the world and he helped me break in mine; slow. Good luck. |
Heh, and if all else fails and it works great and your buddy proves all the motor manufacturers wrong, then so be it. He'll change the whole motor industry and be the last one laughing. Just hope you're right, the RB motors aren't cheap. Just my two cents.:)
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Re: Break-in procedures
Originally posted by Roger Have you guys read up on the "team break-in" procedure on the RB concepts website ?? They have this method that you run your engine at WOT ( wide open throttle ) at 70,80,90 % rich settings. Anybody try this yet. I know a guy that is sponsored by RB and he's gonna break in my motor tommorrow this way. He's broken-in alot of motors this way with great success. I'll let you know what happens. |
Since ti seems more than one of you break in this way. I'd like to know who has concrete results. Not gut feel, I'm talking real numbers.:)
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markp27 has spoken last time....
he said in one of the forum i have read:
post by markp27 he said: The important thing to do in a run-in is to heat-cycle. Therefore one of the most important points is to observe the temperature of the engine. Runing in an engine should not, as Glen has stated, be done by idiling the engine - this doesn't allow the engine to reach the optimum operating temperature. Make sure you set your engine on the rich side and run the engine in the first couple of tanks no more than half throttle - use the HSN to maintain the temp @ 95-105 Degrees C or 200-220 Degrees F. Some say to run the eingine at WOT even at this stage, but my personal preference is to let the components bed-in and not stress them too heavily for the first couple of tanks. After the first couple of tanks then increase the throttle, but maintain the temp as above. Other people have other break-in methods using WOT and higher temps - it is basically personal preference. The one which really doesn't work is letting the engine idle through a few tanks. Cheers, Mark. :tire: mop:tire: |
another person say....
click here
and i quote rodrigo1508 said in his post: Hi I would want your opinion on this post at rcu "Idling an engine, letting it run slow, 1/4, 1/2 throttle is all incorrect. You want WOT after it warms up. YES WOT, even when it is brand new. This is in order to bring it up to the temp and fit the sleeve was designed to run at. Anything less and you are just leading your engine to an early death. Yes, running at WOT slightly rich, but not 4 stroking rich is the proper way to do it. This explains the proper way and WHY it is the proper way. Here is some further explanation I wrote a while ago for newbie nitro guys that were still doing that incorrect idling method: As for break-in, there is a whole lot of misunderstanding about this and basic engine operation. I have read and studied a lot of information on this and also by Dave Gierke who writes in RCCA and Model Airplane News (also by AirAge) about RC airplane and buggy engines and he's an expert. As well as Paris Racing, Stephen Bess, Clarance Lee, etc, in the research I have done over the last few years. It will take some time to convince yourself to bring a new engine to WOT but when you start to understand it and why it is correct, you will realize just how many people are completely breaking the engine totally incorrectly. Its important to learn the theory about how these engines run (2 stroke ABC, ABN, AAC), and how to break-in, especially because I see WAY TOO MANY people using the wrong procedure of idling many tanks of fuel through the engine. That is unnecessary and damaging which I will explain. Although we use the term break-in? by its word alone it is misleading because people wrongly assume it means to slowly and gradually bring an engine to tune by idling tanks of fuel but you will see why this is incorrect and unnecessarily wastes fuel too! Please be patient and read further to understand. These engines use a sleeve around the piston to make the seal (piston doesn't have a ring) and it operates properly only with sufficient heat so that the sleeve can expand to its designed operating size and fit. All engines will be tight, especially when new, so on the initial runs, you want to have it get up to temp, so it can run how it is was designed to. By idling tanks and tanks through, overly rich and cool, the sleeve just wears MORE against the piston because it is not hot enough to expand to its operating size. And by doing that you are prematurely wearing out and ruining your engine. The piston/sleeve is designed to operate at running temps. Not doing this by running cool and rich on the bench leads to premature wear. By idling away tanks of fuel I GUARANTEE you are doing more harm than good. As long as the engine is warmed up first, you dont have to drag out bringing it up to temp when it is brand new. It wont hurt or damage the working parts. These engines are very simple 2 stroke machines. They do not have extensive moving parts such as valves, cams, lifters, springs, etc. (like 4 strokers) so all this extra gentle, rich, cool operation is completely unnecessary (and worse it is harmful). HOWEVER, the sleeve around the piston can be a delicate thing to maintain and it is not forgiving of improper treatment. And improper treatment of a piston and sleeve is running it at a temp it is not designed for. (either too cold or too hot, both are just as detrimental) Most often this is done by running it too rich which makes it too cold because the rich mixture doesn't generate enough combustion heat for proper sleeve expansion. Just as damaging can be an excessively lean run. If it is run overly lean for any length of time it will destroy the sleeve. (that is why fuels with castor oil as part of the lube mix are very good because they tolerate the too high heat of a very lean run and will help to save the sleeve if it is not run too lean for too long. but avoiding a lean run is essential when you know enough enough about engine tuning to avoid it) Running a 2 stroke engine slow and rich makes it '4 stroke' which means it fires every other revolution, and that generates even less heat. It causes damage and wastes fuel as well! Using a fan is absolutely not necessary on it. Most important is to 'heat cycle' the engine at least 10 times to relieve the parts of manufacturing stresses. HEAT CYCLING REALLY IS WHAT BREAK IN IS ALL ABOUT. (I even think break-in should be called initial Heat Cycling?instead so that people understand what and why they are doing it.) You run the engine in the car for 2 - 3 minutes at full throttle (yes, WOT, dont baby it), ideally on a smooth paved level surface, after briefly warming up of course, and then shut down and repeat after the engine has fully cooled. Let it cool down completely. Heat cycling is the name of the game. You want it to come up to temp for a brief time, and cool down and repeat. After shutting down, adjust the flywheel so that the piston is at BDC (bottom dead center) so that it does not get stuck in the contracting/cooling sleeve, as can often happen. (If the piston should accidentally get stuck in the sleeve, preheat the cylinder to free the piston from the sleeve.) During these initial runs YOU WANT the temps to be at least 200 F but not above 230-250 F. After break-in, running temps above 230F is fine. (in fact nitro engines perform best when run 250-300. below those temps they are less efficient and less powerful. However, going by the mixture is more important than trying to measure temp with heat guns, etc. which you may wind up doing inconsistently. The mixture setting on the High Speed Needle is critical in the first runs. It should be a rich and not lean setting. However it should not be so rich that it 4 strokes. Also, to start a brand new engine it is very worthwhile to preheat the engine with a heat gun or hair dryer if it has a very tight piston/sleeve fit and you are having trouble turning it over to start it up. This will expand the sleeve some, and when you turn it over the piston will not excessively rub, or even get stuck in the sleeve (as sometimes can happen). Preheating really works well. You do want to run it on the rich side, but you want it to come up to temp also, just not more than 2-3 minutes in beginning runs, in order to keeps temps around 230F. Listen carefully to the exhaust noise or note? as you do not want it to be ? stroking? If it is, it needs to be leaned slowly until it runs 2 stroke. You can tell it is 4 stroking if it is very boggy?and hesitant?in acceleration and running. If it is making that burbling?sound then it is 4 stroking which means it is running too rich and therefore too cold. Everyone thinks they have to run it super cool and check to be sure temps are low. That's not what it is about. The reverse is true! Cool operation is damaging operation. Little, if any, break-in will occur unless it is heat cycled properly. The manufactures cant make a piston/sleeve turn over smoothly at room temp, because when the engine runs the sleeve will expand and there will be no seal at operating temp. See how that makes sense?! So preheat it if necessary and don't run it cool, and heat cycle it, and you'll be good to go! After you have done this several times then you can gradually lean out the HSN to get best performance, but it should then be richened up just rich of peak to ensure it lasts long too. Running it at max peak rpm will lead to the shortest useful life of the piston and sleeve. If racing that is fine but if you are just playing you may want to run just a little richer than that peak setting. After the HSN is set then it is time to set the low and/or mid range needles and idling setting. I see a lot of people idle the engine for a tank and then they let it cool off thinking that they are "heat cycling" it. However, because they are not running it up to WOT it is not generating enough heat to be of any use to a breakin/heat cycle. So, inadvertently by idling they are just letting the engine sleeve and piston wear away from the cold tight fit that they are allowing to happen when idling away on the bench. Research has shown that basically no breakin effect takes place AT ALL unless the engine is allowed to come up to operating temp for 2 minutes. So if you are idling away and then let it cool there is zero breakin/heat cycle benefit. But if you want to wear away the sleeve and piston fit then idling will definitely do it for you. I hope this is helpful!! P.S. If you want to hear it from him, read Dave Gierken article in the January 2002 issue of RC Nitro magazine! " phew! :tire: mop:tire: |
More and more manufacturers are recomending WOT Break- In method.
After reading a post by Andrea Rossi in Sirio's web site, this is the correct Break-In procedure for the S12's 1.- One (1) tank in the bench at WOT with very rich setting of HSN, avoiding it to go on 4 stroke. COOL DOWN 2.- Three (3) tanks on the track with very rich setting of HSN, and tuning the HSN at the end of third tank to get almost full power. COOL DOWN 3.- For 20% Nitro, use .20 head shim and N° 7 Glow plug. He says after that, the engine will give more power after every new tank. Which means that Breaking-In Sirios, should be done with more or less 300 to 500cc of fuel. AFM |
Well, after reading this thread I just can't stay quiet anymore. I've been racing some form or another all of my life. I've tuned or helped tune everything from go kart motors to $45k pro mod door slammers. In all that time I have learned a little about race motors. With that knowlege I have ALWAYS been against the typical nitro r/c motor break-in procedures. I totally agree with the above quote by whoever wrote it originally. There are a number of reasons why I disagree with conventional break-in methods, but the most important are:
1) heat cycling- rich and slow means not enoug heat. 2) aluminum connecting rod stretch. if you break in a motor with al rods at low RPMs and begin the mating of the piston and sleeve (since r/c motors don't have rings) then when you go to WOT the piston actually goes higher than it did during break-in and begins to destoy the surfaces. I would advise anyone having trouble starting a new or tight motor to hit the head and sleeve area with a heat gun set to high. This will expand the sleeve and make life much easier |
This is what Rody said about this method… he also posted he runs a 7X4 prop on the motor
“Anyway, if you still want to do it in this way, I think in this way you cannot do a lot of things wrong. So before you start to run in an engine I suggest you cover the cooling-head with something so the engine heats-up properly(without the cover the engine will stay too cold). Then start the engine and let it run rich at full throttle for 2-tanks at a temperature of about 80°C. Then 2 more tanks at 90°C. Then 1 more tank at 100°C. After this your engine is almost run-in, however you need to finish the rest of the running-in in the car for about 2 more tanks and you are then ready to go. With the engine full-throttle, you are sure that the idle needle is not in front of the spraybar and so you are running the engine really on the setting of the main-needle and so are also sure the engine will run rich. Also more fuel/air will go through the engine with full throttle so a better lubrification.” |
Originally posted by ottoman Also more fuel/air will go through the engine with full throttle so a better lubrification.” |
Originally posted by GUNPOWDER This is referring to full throttle with car running on the track yes? (Not a bench run??) AFM |
If you don't have a bench, how would you run in your engine in the car? Just have a rich setting and run WOT up and down the straight at the track?
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how do you run the car (wot) on the track ? I can see doing it on a bench or starter box...:confused: :confused:
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Originally posted by Q how do you run the car (wot) on the track ? I can see doing it on a bench or starter box...:confused: :confused: |
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