Engine breakin
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From: Seminloe, FL
I'm ready to start my new fantom .18 in my t-maxx.The manual say's start and run in truck @ 5 to 10 sec blips,checking/setting the highspeed needle as you go.My question is,does it have to be running down the street,5 to 10 sec's and I'll be chashing her down the next subdivision,lol. Can I remove the tire's and breakin the engine on a stand? Would that not be better,no lost control,no running into stuff,easier to tune?How are you folk's breaking in your t-maxx engine's? Any help will be great!!!!!!
Thanks
ken
Thanks
ken
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From: LondonKILIMANJARO, TANZANIA
don't do that, the engine has to have a load on it when breaking it in, which is why they say to run it on the street, there won't be much lost control with an engine on break in, you should be running really rich, and the car won't pick up speed....also, a tip, we've gone over this a million times, so please search the forum about it...check out www.rbproducts.com and click on forum to see more ways on break in.
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From: Fitchburg, MA
Hi ; I'm about to break-in a new OS Vo1b .21 engine; I mean tight; is this engine; I burnt up my rubber starter box wheel on the first atempt to start; and loosened the glow, but then flooded it; some say try a hair dryer to preheat? any suggestions would be appreciated. Thanks John
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Use a heat gun or hair dryer on the head some. This will allow the top tapered portion of the sleeve to slightly expand so it can turn over easier. Get it running and then driving as soon as you can then. And NO IDLING!!!
See this:
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.
It’s 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-inâ€, 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 don’t 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’s 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, don’t 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 ‘4 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 can’t 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 Gierke’s article in the January 2002 issue of “RC Nitro†magazine!
See this:
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.
It’s 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-inâ€, 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 don’t 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’s 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, don’t 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 ‘4 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 can’t 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 Gierke’s article in the January 2002 issue of “RC Nitro†magazine!
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From: Oxnard,
CA
GREAT, GREAT INFORMATION.
THANKS ALOT
This makes complete sense to me. I have a good understanding of metals and their thermal expansion properties , which is why I always questioned the reason why we had to break it in slowly,. This helps affirm my thoughts.
This web site rules !!!!!!!!!!!!!!!
THANKS ALOT
This makes complete sense to me. I have a good understanding of metals and their thermal expansion properties , which is why I always questioned the reason why we had to break it in slowly,. This helps affirm my thoughts.
This web site rules !!!!!!!!!!!!!!!
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From: Sylvania,
OH
WOW!!!!!! That was very very informative!!!! I understand so much more now about break in. There is so many differnt ways to break in an engine, and I couldnt decide on how to break in my os 18 tm engine, but, I think I will go with that heat cylcing way, WOT. Thanks so much for giving out that information!!!!!!
#9
I imagine this thread may not be looked at, but are you saying the engine maker's manual should be ignored? What you say makes complete sense (I am not an expert, but I have plenty of mechanical knowledge because I was a helicopter mechanic). I have a Revo and I followed the instructions to the letter. I now have a dog of a motor that won't even lift the wheels off the ground. I know that the best launch is one that the wheels stay on the ground, but I think the motor is a bit underpowered. Could this have been my fault from following the instructions? Furthermore, why would a manufacturer lie to it's customers? It is possible that I am running my engine too cool (about 200 by temp gun, but I am not sure what the emissivity level of blue, anodized aluminum is). If I could get some help that would be fantastic. I wouldn't want to spend money on a new motor when I could get the most out of this one (btw, I have the stock 2.5r in it still)
#10

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I imagine this thread may not be looked at, but are you saying the engine maker's manual should be ignored?
I have a Revo and I followed the instructions to the letter. I now have a dog of a motor that won't even lift the wheels off the ground. I know that the best launch is one that the wheels stay on the ground, but I think the motor is a bit underpowered. Could this have been my fault from following the instructions?
Furthermore, why would a manufacturer lie to it's customers? It is possible that I am running my engine too cool (about 200 by temp gun, but I am not sure what the emissivity level of blue, anodized aluminum is).
If I could get some help that would be fantastic. I wouldn't want to spend money on a new motor when I could get the most out of this one
Take a new engine out of the box, throw away the instructions (except of needle starting points),
Squirt a ltttle bit of oil in it fo some additional start up lube,
Check both needles to insure they are at the factory defaults,
Fire it up and immediatly get the engine up to design tempreture by tuning it to a rich but clean running condition (worry about the low speed needle after a tank or two),
You do not want it to run slobbery rich, you want it to run clean, but not lean. PERIOD
Short wide open 5 ot 10 second blips is fine, grass, road, it does not really matter, but you must have full throttle running in there.
It is really that simple!, no VooDoo, no mystical magic, just pure simple and easy. After the first couple tanks running that way (with complete cool downs between tanks), you can start leaning out the high speed needle and dialing in the low speed needle. The key to success is crisp and clean running for break in. You will do more harm than good if you allow it to idle or run at all in a slobbery condition.
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From: SAN DIEGO, CA CA
Lots of very good information here, I am ready to breaking-in my rebuilt motor. My problem is I dont have much time during the day, I take care of 2 kids and work at night, during the day I have about an hour window to do what ever i can. (Nap time for the kids) I can run the motor for 1 tank a day and be finish in a week. Is this okay? or should I wait till I have enough time to perform the heat cycling in one shot.
I am also pre-heating my engine before start-up with a butane pen torch. I kinda dont like to be carrying around a hair dryer or a heat gun in the park, a pen torch and a lighter is much more convenient for me. I do this by placing my palm about 8 inches away from the blue flame and then slowly placing it closer till I feel the heat, then thats how far away I would place it from the engine . I'll do this for about a minute until the head feels very warm to the touch, this is ofcourse before I put any fuel in the tank.
Am I doing the engine any good by warming it up this way? Or Am I doing it more harm than good?
Thanks,
I am also pre-heating my engine before start-up with a butane pen torch. I kinda dont like to be carrying around a hair dryer or a heat gun in the park, a pen torch and a lighter is much more convenient for me. I do this by placing my palm about 8 inches away from the blue flame and then slowly placing it closer till I feel the heat, then thats how far away I would place it from the engine . I'll do this for about a minute until the head feels very warm to the touch, this is ofcourse before I put any fuel in the tank.
Am I doing the engine any good by warming it up this way? Or Am I doing it more harm than good?
Thanks,
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From: Lancaster, PA
emissivity level of blue, anodized aluminum .87
http://www.electro-optical.com/bb_ra...inum%20Samples
See About Halfway down
http://www.electro-optical.com/bb_ra...inum%20Samples
See About Halfway down
#16
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From: SydneyNSW, AUSTRALIA
And make sure you use a temp gun to see what heat the flame is.. Then throw the temp gun into a lake and record the water temps .. you can usualy leave it in the water for at least a week before the battery goes off.. lol
no seriously you should temp everything in sight its loads of fun ! : )
no seriously you should temp everything in sight its loads of fun ! : )
#17
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From: , CA
heat cycling to releive manufacturing stresses?? ok i break in my motors be starting them and getting them up to temp, using a heat gun prestart is a good idea. Then run at least 5 tank fulls without letting the engine shut off, making sure to either have the engine under load or off the throttle. My truck smokes all of my buddies trucks. it has the stock savage motor in it and they have a savage and two revos. all three with stock motors. heat cycling is bs



