Lets discus the break in process in this thread.
I am currently looking for a good break in method so this can help me a lot.

The following was posted by BaxterC

This one was suggested by afm

This is Initial D about his WOT style

i think the 1st one is the easiest to understand

Very controversial subject, I will give you my short and sweet method I developed after owning mroe nitro engines than I can remember though. Crank it, lean it, get it over 200 degrees as quick as possible, put it on the ground, run it, not wide open but don't baby it. Do this for a few minutes, shut it down, BDC the piston, let it cool completely, re fill tank, crank it again. 200 as fast as possible, run it again another 3 minutes or so. I do this about 10 times and call it good, lean it the rest of the way, and its ready to race. The reason I do this is simple, metal expands when it get hot, and wears as it rubs on other metal. Breaking in an engine cold and rich does not allow the sleeve to expand where it will be when its hot therefore there is going to be more wear on the piston liner and the piston if it is broken in cold causing lower compression upon completion and overall shorter life and less performance. I have used the method on everything from Picco .12's to V01B's to RB WS7's and it works great. The other method used on similar motors has shortened life and lowered power significantly. I can say this becuase I am a rebuild freak, my motors get rebuilt completely quite a lot to keep the most power out of them for racing as they don't even come off the shelf just to play with, only for the track. In a couple of gallons I will rebuild a motor so I can tell a difference as the last engine break in was not that long ago.

They say , at least Initial Dm that he does that because that way the piston and sleeve ends up polished.
What I normally been doing is the first 1 or 2 tank at idle and then start to run the car very slow with blipings to get it to 200 and then let it cool completly this for about 10 tanks each tank increasing the throttle, once I get to WOT I start to lean it.
Right now I have gone through 1 tank at idle very rich for 2 minutes cycles and then turn it of, it get to 170 ,I think Ill do this for one more tank and then put it on the floor start the blipping until 200 turn it of to cool and again for a few more tanks, I have all this week to do this and the next to set the needles.
What do you think of my method?

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-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 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!

Thanks for the info, It makes a lot of sense but now I am at the middle of my break in and now dont know what to do, if change it or just finish it. I think may be I will do a mix of both, I was going to do what I said in the past post but decided to do WOT method at very rich settings , now I have about 10 tanks, what do you suggest I should do? should I just keep with this break in or bring the engine to 200 temps and cycling.

Get the engine up to temp, the longer you run it cold, the more you are causing early wear on the internals because they are not able to expand.

I preheat my engines with a heat gun before/during break in. I bring the temp at the glow plug to 180-200 degrees before kicking it over on the start box. I get the idle mixture good and let her idle 2 tanks at 200 fairly rich, enough to sustain that 200 degree range.

I then run another 2 tanks on the road 1/4-1/2 throttle, then just baby it for a few tanks after that and im all good. I dont stop heat gunning it until after I finish the break in, that way the engine is always up to temp before I start to avoid premature piston/sleeve wear.

I got this from the RB forum from Rody himself

"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."

I stop doing the WOT rich thing and did this.

I would give it several short runs at WOT and gradually lean each one out. After a few runs tune it and drive it as you normally would. As long as you get it up to temp and don't do any prolonged idling is best. A good breakin should be accomplished in less than 10-15 runs of 2- 3 minutes each. Anything above that is really useless and just a waste.

Rody says rich at full throttle. That is is WOT is, Wide Open Throttle. So following his advice and WOT is the same thing.

im putting a new piston sleeve in mine tonight, i like the WOT method as it makes sence and should go quick.

as the rest of the engine has been heat cycled is there any other issues to worry about if your just putting in a new piston/sleve?

He does say that but to achieve the 100 C (210 F) I had to lean it. So I think that his method was pretty much the same as yours, you say to bring the engine around 200 F and that is what he is also saying, thats why I desided to use it
I do know what WOT stands for I was just trying to say that I was going to up the temps as you said.

I think Nitro-Keebler is on to something with the idle it through the first couple of tanks with the deat gun blasting it. Doesn't this give you the best of both worlds - High heat to avoid premature wear, while at the same time, no excessive strain on an engine that is trying to mate the piston and sleeve.

sounds good to me

your reasoning sounds like it makes sense but it is incorrect. part of the reason for the breakin is to preserve the tight piston sleeve taper fit at the very top of the compression stroke (top dead center). the only way for the top of the sleeve and therefore the cylinder as a whole to expand properly from the inside is to run it up to wot without an overly rich setting. idling even with a heat gun is not the same, because it cant duplicate the heat creation scenario as when it comes from the actual combustion chamber internally when run at wot. using a heat gun cant duplicate what the engine does naturally and is designed to do. there are tremendous temps and pressures created in the combustion chamber/cylinder and that is what you want to occur as soon as possible for proper breakin, and a heat gun cant do that. the faster the sleeve expands on its own natural way the better for your breakin. when the sleeve expands under the engine's own natural internal combustion cycle heat generation it means you are preserving that tight and proper piston sleeve fit, whereas running it cold doesn't allow the sleeve to expand so it just wears out more and erodes the piston sleeve fit. stress relieving the engine with the correct 2 - 4 minute runs for about 12 times/runs of heat cycling with cool down times is far wiser than any idling and heat gun use. idling is one of the worst things for an abc/abn/aac non-ringed nitro engine.

It is bad to run it WOT when it is blubbery rich, as in the break in settings. You will end up damaging the connecting rod. Also, when he says WOT, he means getting the engine up to wide open and letting it come back down, not holding it at wide open for long periods of time (or so I hope..).

how much are you soppuse to lean the engine out every tank or 2 sorry guys dont have enough time reading this long thread

why do everybody got there own breaking "method".

I know this sounds newbish (and yes i am). I bought a maximum MT plug the tape they gave me into the vcr and did exactly what they said to do for breakin.

Now i wounder if I would have been better off fallowing one of your methodes.

In any case how long can a engin be expected to live?
I would also like to know the difference between a Torq engin and a none-Torq.

Your engine will last ages if you treat it right. The engine in my CEN car is 4 years old, and has had gallons through it and it still goes as strong as ever with full compression etc...

As long as you follow some break in procedure ie run it rich for a while then lean it out your engine will be ok. I agree with shoestring racer that the best method is to get it up to temp fast and run it.

***? Am i missing something?

Torque is the pulling power you get from an engine, is what gives you your acceleration, its partially linked to horsepower but not directly. Torque is more important in an engine than horsepower. It can be improved in no end of ways...by porting the engine etc, this also increases horsepower...

Cheers
David

Shoestring is right on the money.
I make glow fuel and run engines for a living and the one thing that always baffles me is why the break in instructions for most these car engines are written incorrectly. You must get it up to operating temp (about 230F in an ABC type engine) as rapidly as possible and heat cycle the engine with complete cool downs like shoestring mentions. I have even gone so far as wrapping some foil around the cooling fins when its cold outside on some of these engines just to retain enough of the heat so the top of the sleeve will expand to design fit. Never think you're breaking in an engine by letting it sit and idle for a tank or two blubbery rich, you are just destroying the piston / sleeve fit and setting up the manufacturer for another parts sale.
If you break them in like Shoestring suggests and tune them correctly, you can get 10 or more gallons of fuel through an engine. I have had as many as 20 gallons through a cheap buggy engine with carefull tuning.

Fuelman, it's business.......it's business strategy so that the sales will keep on rolling.
They don't want the engine to last for a very long time......

Shoestringracer and Fuelman are both right.

You MUST get the engine up to operating temperature! Otherwise the piston is too tight in the sleeve and you are just wearing away the piston. (Granted after this break in your engine will seemed to have 'losened up', but the only reason would be because of this wear!) Once its there you need to keep it there by applying whatever throttle is needed, if that be WOT then so be it. Remember at this point that the engine will be running so rich that WOT will only seem like half throttle on a well tuned engine....

Cheers,
David