How do you break in the MGT
05-18-2007, 02:36 PM
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How do you break in the MGT
He whats up, my friend is buying an MGT 4.6, but will he be useing the heat cycle break in method. Could some one give me a site that explains how to do this. Im not familiar with the heat cycle method. Any help will be much appreciated. 
05-18-2007, 03:24 PM
#3
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RE: How do you break in the MGT
Basically, first thing to do is take out the glow-plug, look down in the hole, rotate the flywheel with your finger, and find out the exact point where the piston is all the way at the botoom. Then, what I do is scratch a notch in the flywheel at 12:00. Then, with the glowplug in, I know when the piston is all the way at the bottom. There may be a more elegant way to mark BDC, but I just scratch a notch on the flywheel.....
Then, when you're ready to break-in, depending on the outside temp where you are, if it's not hot out wrap the cooling head in an old sock. The whole point of heat-cycling is to get the temps up to 200 or slightly over, and then to let it cool down completely with the piston at its absolute bottom position. So, run the car very gently in figure 8's, and monitor the temps with a temp gun. After 2 minutes or so, it should hit 200, then shut it down, rotate your flywheel to 12:00, and let it cool completely. Repeat - like 10 times.. That's what the text says - but I do it probably like 20 times..... Break-in is not exciting...
Here's the text everybody seems to refer to:
Good luck..
"This was copied from a post by STEPHEN BESS on the "Starting Grid" message board as he tried to help another member get more life and performance out of his OS motor. This break-in method should apply to virtually any ABC hobby nitro engine (except for ringed engines).
If you are still idling at least a tank through during break-in, you're using the old-school accepted method (still works well for some!) but it's not the method that the top engine guys (Ron Paris, Dennis Richey, Rody Roem, Michael Salven are just a few I've spoken personally with about this) recommend anymore.
From the very 1st time you start your engine, plop the car on the ground & begin running it in a parking lot in 2-3 minute intervals, tuned only *slightly rich* getting the temps up in the 200F range on a normal day. Every 2-3 minutes, shut the engine down & let it cool completely with the piston at BDC, and then fire it back up; continue this cycle until you've run 15 min or so, and then bump up to 3-4 minute intervals. Vary the RPM and don't be afraid to get the temps in the 200's. What you want is heat cycling of the components without the incredible stress that comes with breaking an engine in when it's overly rich & cold. After cycling the engine in this mannerfor about 20-25 total minutes, it'll be ready for the track and race tuning. I realize this method goes against the old-school "idle on the box" routine, but you'll be amazed once you've completed this break-in routine, your OS will still have amazing pinch w/out sticking at the top AND your OS's compression will last far longer than it will with the "old school" method.
You say you run the engine at "factory settings" for the first FIVE tanks? That alone causes lots of stress, as the factory OS settings are very rich on every OS I've ever owned or tuned. The piston & sleeve haven't expanded to operating temps, and every time the engine turns over, the piston slams into the pinch zone at TDC. The not-so-surprising result can be a cracked con-rod at the crank pin--that's where the majority of the stresses occur as the engine turns over. I've only heard of about 6-8 OS engines breaking con-rods, and they're ALWAYS during the first gallon...and almost every time it's because the guys have performed the break-in procedure you described. Doesn't seem like a mystery as to why it's happening. Drawing out the break-in routine really stresses the engine & actually wears away compression along the way. This method I've outlined will feel weird at every step, but after you try it once, you'll notice a big difference in your engine's performance & lifespan.
Hope this helps; give this break-in method a shot--you have nothing to gain except longer life & more power
"
Then, when you're ready to break-in, depending on the outside temp where you are, if it's not hot out wrap the cooling head in an old sock. The whole point of heat-cycling is to get the temps up to 200 or slightly over, and then to let it cool down completely with the piston at its absolute bottom position. So, run the car very gently in figure 8's, and monitor the temps with a temp gun. After 2 minutes or so, it should hit 200, then shut it down, rotate your flywheel to 12:00, and let it cool completely. Repeat - like 10 times.. That's what the text says - but I do it probably like 20 times..... Break-in is not exciting...
Here's the text everybody seems to refer to:
Good luck..
"This was copied from a post by STEPHEN BESS on the "Starting Grid" message board as he tried to help another member get more life and performance out of his OS motor. This break-in method should apply to virtually any ABC hobby nitro engine (except for ringed engines).
If you are still idling at least a tank through during break-in, you're using the old-school accepted method (still works well for some!) but it's not the method that the top engine guys (Ron Paris, Dennis Richey, Rody Roem, Michael Salven are just a few I've spoken personally with about this) recommend anymore.
From the very 1st time you start your engine, plop the car on the ground & begin running it in a parking lot in 2-3 minute intervals, tuned only *slightly rich* getting the temps up in the 200F range on a normal day. Every 2-3 minutes, shut the engine down & let it cool completely with the piston at BDC, and then fire it back up; continue this cycle until you've run 15 min or so, and then bump up to 3-4 minute intervals. Vary the RPM and don't be afraid to get the temps in the 200's. What you want is heat cycling of the components without the incredible stress that comes with breaking an engine in when it's overly rich & cold. After cycling the engine in this mannerfor about 20-25 total minutes, it'll be ready for the track and race tuning. I realize this method goes against the old-school "idle on the box" routine, but you'll be amazed once you've completed this break-in routine, your OS will still have amazing pinch w/out sticking at the top AND your OS's compression will last far longer than it will with the "old school" method.
You say you run the engine at "factory settings" for the first FIVE tanks? That alone causes lots of stress, as the factory OS settings are very rich on every OS I've ever owned or tuned. The piston & sleeve haven't expanded to operating temps, and every time the engine turns over, the piston slams into the pinch zone at TDC. The not-so-surprising result can be a cracked con-rod at the crank pin--that's where the majority of the stresses occur as the engine turns over. I've only heard of about 6-8 OS engines breaking con-rods, and they're ALWAYS during the first gallon...and almost every time it's because the guys have performed the break-in procedure you described. Doesn't seem like a mystery as to why it's happening. Drawing out the break-in routine really stresses the engine & actually wears away compression along the way. This method I've outlined will feel weird at every step, but after you try it once, you'll notice a big difference in your engine's performance & lifespan.
Hope this helps; give this break-in method a shot--you have nothing to gain except longer life & more power
"
05-18-2007, 08:49 PM
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RE: How do you break in the MGT
Here is my break in process. I first prop it up so the wheels are not touching then fire it up and let the first tank idle about half way through and check temps as I go. Then I blip the throttle off and on to about 1/8 throttle till its in the 200's then I shut it off. Do that untill the tank is empty. Then after that I let it cool and fuel it back up and then drive around real slow for another tank and not even worry about the temps..... just make sure its not to hot. Then the third is done the same as the second tank. Then 4th tank gets a 1/8 turn lean on the carb and done the same as tanks 2 and 3. Then I consider it broken in and take it easy untill after tanks 8 to 10. Thats when I start leaning it out more and more till its tuned up good.
