scottm
Hardcore RCTalk User
I was surfing over at radiocontrolzone.com (a vastly inferior site to this one, of course!) when I came across this post by Steve Pond in response to a question about temperature. It is on one of my favorite subjects that I prattle on about all the time, break in technique. So here is a reminder about proper break in:
http://www.radiocontrolzone.com/forums/showthread.php?s=&threadid=161018
Steve is the Technical Editor of RC Car Action and an administrator at rcz, and is probably the world's leading advocate of heat cycling and hot temp break in. The Cliff's notes virsion of Steves method is to get the engine hot (200 F) with a heat gun before starting it the first 15 times or so. Run it rich, but not blubbery rich, at 200 to 220 F, for 1 minute at a time. Let it cool completely with the piston at the bottom of the stroke, repeat 5 times. Then go to 2 minute intervals, then 3 minute intervals. You can be driving it during this time at up to 1/2 throttle.
I have experimented with the propeller break in method, as shown here in my gallery:
https://www.rcnitrotalk.com/gallery/showphoto.php?photo=2789&papass=&sort=1&thecat=500
But that is unnecessary IMO. Most of the benefits come from getting it hot first, so just get it hot and drive it. Running it cold is the biggest mistake. Here is a quote from the OS website:
"How Do I Break In My R/C Car Engine?
The break in process of model engines, especially R/C car engines has been affected by a wide variety of myths and misconceptions. The main one is that the engine must be run at idle for several tanks' worth of fuel before the model is run. There is nothing farther from the truth! In fact, running the engine at idle for several tanks' worth of fuel will not only insure that your engine won't break in properly, but it could also reduce its overall life!
The purpose of the break-in process is to run the engine so that its moving parts will polish each other to a perfect fit. This requires that the engine be run at a variety of throttle settings so that the different parts will be affected by changing pressures and temperatures.
Typically, we start out with a moderately rich needle setting and start driving the car right away. We accelerate to a medium speed and then coast. Turn around and come back the same way. If the high-speed needle is so rich that the engine tends to hesitate a lot when throttle is applied, we'll lean it a bit to eliminate most of the hesitation.
After a few minutes of this, we start accelerating to a high speed and then coast. Turn around and come back the same way. We do this for the remainder of the first tank.
During the next two to three tanks' worth of running, we gradually lean the high-speed needle valve until the engine will run at full throttle at a setting just rich of peak RPM. One way to tell that the engine is on the rich side of peak RPM is to accelerate to full throttle and carefully listen to the engine. It should accelerate up and hold RPM, and not sag back down.
With the CV-series of engines, we'll set the high-speed needle about 2-1/4 turns open and lean from there. When fully leaned, the needle will be between 1-3/4 to 2 turns out from closed. The engine may still run with a leaner setting on the needle, but that setting may be lean enough to allow the engine to gradually overheat and quit. An overheat is a bad thing, and it will cause the piston/cylinder fit to go bad very quickly. "Thermal overload" is just another term for overheating.
If the engine is set too lean, the engine's internal parts can be damaged because they'll be starved of lubrication. Remember, the engine's lubrication is contained in the fuel, and a too-lean setting means too little fuel, which translates into too little lubrication.
Finally, O.S. states in their engine instructions that you should use a fuel that has an oil content of no less than 18% by volume. Many so-called "R/C Car" fuels contain oil in the 12%-14% range. While these may work quite well when the engine's set correctly, low-oil fuels do not leave much margin of error if the engine gets a lean run. Nitro content can be as high as 20% by volume without worry about special engine tuning or setup."
Read more from OS here:
http://www.osengines.com/faq/product-faq.html#q590
I have done engines the old cold way and the new hot way. Both run fine for a long time. But the hot break in engines still have so much compression after 1+ gallon that they are hard to start cold, just like they were new. I am now in the habit of warming my engines every time, and there is no doubt in my mind that they are going to last longer amd make more power.
http://www.radiocontrolzone.com/forums/showthread.php?s=&threadid=161018
Steve is the Technical Editor of RC Car Action and an administrator at rcz, and is probably the world's leading advocate of heat cycling and hot temp break in. The Cliff's notes virsion of Steves method is to get the engine hot (200 F) with a heat gun before starting it the first 15 times or so. Run it rich, but not blubbery rich, at 200 to 220 F, for 1 minute at a time. Let it cool completely with the piston at the bottom of the stroke, repeat 5 times. Then go to 2 minute intervals, then 3 minute intervals. You can be driving it during this time at up to 1/2 throttle.
I have experimented with the propeller break in method, as shown here in my gallery:
https://www.rcnitrotalk.com/gallery/showphoto.php?photo=2789&papass=&sort=1&thecat=500
But that is unnecessary IMO. Most of the benefits come from getting it hot first, so just get it hot and drive it. Running it cold is the biggest mistake. Here is a quote from the OS website:
"How Do I Break In My R/C Car Engine?
The break in process of model engines, especially R/C car engines has been affected by a wide variety of myths and misconceptions. The main one is that the engine must be run at idle for several tanks' worth of fuel before the model is run. There is nothing farther from the truth! In fact, running the engine at idle for several tanks' worth of fuel will not only insure that your engine won't break in properly, but it could also reduce its overall life!
The purpose of the break-in process is to run the engine so that its moving parts will polish each other to a perfect fit. This requires that the engine be run at a variety of throttle settings so that the different parts will be affected by changing pressures and temperatures.
Typically, we start out with a moderately rich needle setting and start driving the car right away. We accelerate to a medium speed and then coast. Turn around and come back the same way. If the high-speed needle is so rich that the engine tends to hesitate a lot when throttle is applied, we'll lean it a bit to eliminate most of the hesitation.
After a few minutes of this, we start accelerating to a high speed and then coast. Turn around and come back the same way. We do this for the remainder of the first tank.
During the next two to three tanks' worth of running, we gradually lean the high-speed needle valve until the engine will run at full throttle at a setting just rich of peak RPM. One way to tell that the engine is on the rich side of peak RPM is to accelerate to full throttle and carefully listen to the engine. It should accelerate up and hold RPM, and not sag back down.
With the CV-series of engines, we'll set the high-speed needle about 2-1/4 turns open and lean from there. When fully leaned, the needle will be between 1-3/4 to 2 turns out from closed. The engine may still run with a leaner setting on the needle, but that setting may be lean enough to allow the engine to gradually overheat and quit. An overheat is a bad thing, and it will cause the piston/cylinder fit to go bad very quickly. "Thermal overload" is just another term for overheating.
If the engine is set too lean, the engine's internal parts can be damaged because they'll be starved of lubrication. Remember, the engine's lubrication is contained in the fuel, and a too-lean setting means too little fuel, which translates into too little lubrication.
Finally, O.S. states in their engine instructions that you should use a fuel that has an oil content of no less than 18% by volume. Many so-called "R/C Car" fuels contain oil in the 12%-14% range. While these may work quite well when the engine's set correctly, low-oil fuels do not leave much margin of error if the engine gets a lean run. Nitro content can be as high as 20% by volume without worry about special engine tuning or setup."
Read more from OS here:
http://www.osengines.com/faq/product-faq.html#q590
I have done engines the old cold way and the new hot way. Both run fine for a long time. But the hot break in engines still have so much compression after 1+ gallon that they are hard to start cold, just like they were new. I am now in the habit of warming my engines every time, and there is no doubt in my mind that they are going to last longer amd make more power.
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