EdwardN

iTrader: (1)

From my expirience, Josh's method is realy great and if follow it-results for sure will be positive.
About materials, as it goes on conventional set ups-ABC or AAC, yes they expaniton rates are very critical.
In my particular case ( BRB set ups) and we did a lot of testing on all variety of temp, the temperature doesn't make big difference ( in reasonble limits). Actualy hoter you running is better, but again, in the limits.
About changing conrods-yes on all mass production engines it has to be done. But there is materials available much better and works 4-5 times longer then stock, but this is different story.
Conclusion-yes Cyrul"s method is really good and usefull and I recomend to everybody follow it up.
Edward

revzalot

iTrader: (4)

I especially like how you keep opening the top end needle at WOT to clean all the junk out of the motor while breaking it in or tuning it. Very nice method!

cdelong

iTrader: (12)

I never fire up a new engine without opening it up and cleaning the internals first. I don't care how much fuel you are flushing through an engine- if there is really any metal fragments in there before you start it up you will damage the engine. It only takes 10 minutes to open the engine and clean it with some denatured alcohol or old fuel and compressed air.

revzalot

iTrader: (4)

Good advice cdelong. Yes clean is fast! Can I just take off the back plate, heat sink head, and carb off, then spray fuel throughout the innards of the motor?

cdelong

iTrader: (12)

I take it down to bare bones- just leave the bearings in the block. I have a RB V12 arriving tomorrow and think I'll try this break-in method on it. I've never had a problem with "puttering" around the driveway around 200- 220F, but this sounds quicker.

coldfusion

Just a question on cleaning and blasting air into the engine - i was told you should not blast air directly into the engine bearings as this would cause damage to them but anywhere else in the internals are fine. Is this true?

...

Before last weekend the piston on my RB V12 5 port could only travel half way up the sleeve. After last weekend's Asian Mugen Cup Finals, it now travels all the way up the sleeve infact slightly above the top of the sleeve without any compression left? I was running with 0.4 head shims, No.6 nove plug, 25% byron and at a race temp between 110-130c. There is slight freeplay between the conrod bushing and the crank pin. What went wrong?

jeffreylin

Josh, I hope you will see this but here is my question with your method.

I tried it step by step but that engine died in the middle of a race--a broken piston. Luckily it was a handout motor ($50 for race entry includes a motor). It wasn't the best motor out there so the failure could've been due to material or worksmanship.

But looking back, I see a problem. You stated that once the engine is up to temperature, we should richen the top needle until the engine flames out. Well I had to open it so much before it flamed out that the engine cooled down and was only running at about 100F. That couldn't have been good?

Also, as mentioned in other posts before, wouldn't full throttle for 5 tanks especially when the engine is tight and temperature is lower be bad for the con rod? I mean yes replacing it is always a good idea but having to replace a $20-$30 con rod right after breaking in seems a bit excessive doesn't it?

I hope you and everyone don't take this the wrong way. I am just curious. Please let me know if I am not following your method correctly.

And if you actually saw the post, good luck with the Reedy and I can't wait to see that new Kyosho car!

CD3 RACING

You can try this one http://www.johnnycoolguy.com/JCGR/ma..._break-in.html

BigDogRacing

iTrader: (12)

A broken piston probably has very little to do with the break-in method. My name isn't Rody or Cyrul, but I'm guessing the most likely reason for a broken piston is poor materials or possibly over revving.

If the motor was up to operating temperature and you richened it until it flamed out it shouldn't have dropped that much. Also, he only suggests doing that to flush out the motor. If it was new and clean it probably didn't need to go to the full extreme of flaming out. However, even still it didn't hurt the motor.

When the motor is above 175F the piston isn't anywhere near as tight as it feels when cool. The reason it's tight when cool is because the sleeve has contracted and is pinching the piston at TDC. This is another reason I try not to rev my motor(s) hard until they have been started a few seconds. I set the hi idle on my radio to start the motor and let it hi idle for 8-10 sec.

I'm sure Josh won't be on here any time soon because of the Reedy so I hope I was able to help a little

jeffreylin

Thanks Jason. I think that is good we are discussing these because if someone did as the instruction he/she might be breaking-in the engine at 100F like I did. Not good.

Since that experience, I have broke in a couple of engines following Josh's method but with some changes. Instead of running it very rich, I just run it at perhaps a turn or two rich, and keep the tempurature at above 180F. Instead of running it WOT the whole time, I will do full throttle for a second or so and idle for 2-3 seconds. I figure this way I am breaking-in at operating temperature and am not working the con rod too much. It takes quite a bit longer but both of the engines I broke-in have been very fast and reliable.

fastharry™

iTrader: (4)

so I followed the procedure on the first tank......then it started to rain..here's my question........warmed it.......Flamed it......leaned it 1/4 turn.......ran the 1st tank...engine never got over 120 degrees......

brand new rb turbo..measured with a Ray tech gun.....in a r40....

I still feel funny that the motors not hitting 190-200.......of course,if you read RODY's instructions,he wants you to run the car on the track....with the motor just about 4 stroking....and not high rpm.....

pretty much doing the same thing....But I'm gonna go with Josh's method..which is quicker,easier,and less of a PIA....

any reason I shouldn't be concerned?....

ontheroad

Hİ!
What about the methods in the motors manuel?
In Tz's manuel it says " Try to make time to run the car at full throttle. Lenghten full throttle runnibg time gradually. When the car can run full throttle, close the needle valf, etc"
So it is close to cruel's method. What about other manuels?

fastharry™

iTrader: (4)

it seems all the manuels wwnt you to run the enine rich.....when I followed Rodys RB instructions,the motor never got over 140 for the first few tanks either.........

neither will the os if you run it like they want you too...it seems like they want you to run the cars with no regard to temps during break in...and that getting fuel is the motor is more important...

afm

WOT BREAK-IN

Idling an engine and letting it run slow, 1/4, 1/2 throttle is incorrect. You want Wide Open Throttle after it warms up. YES Wide Open Throttle, even when it is brand new. This is in order to bring the engine up to temp. and fit the sleeve to what it 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. Here is some further explanation of ” the way”, and why it is the proper way.

As for break-in, there is a whole lot of misunderstanding about this basic engine operation.
Although we use the term “break-in”, by its wording 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!

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 them 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.

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 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. 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.)

Run the engine in a bench for 2 - 3 minutes at full throttle (yes, WOT, don’t baby it), 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.). Follow this procedure for at least 3 tanks, then put the engine on the car and do another 3 tanks at the track to finish Break-in, leaning the engine a bit after every run

During these initial runs YOU WANT the temps to be at least 90° C but not above 109° C.
After break-in, running temps above 109°C is fine. In fact new generation nitro engines perform best when run at 120°C – 130°C. 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 keep temps around 109°C. 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 break-in/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 break-in 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 break-in/heat cycle benefit. But if you want to wear away the sleeve and piston fit then idling will definitely do it for you.

As you’ve read, 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 enough heat.

2) Aluminum connecting rod stretches. If you break in a motor with aluminum 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 destroy the surfaces not used.

I hope this is helpful!!

AFM

P.S. If you want to hear it from him, read Dave Gierke’s article in the January 2002 issue of “RC Nitro” magazine! "

This is what Rody Roem from RB Concept says for Break-In

Before you start to Break-in an engine on the bench, I suggest you cover the cooling-head with something, so the engine heats-up properly FOR ONE TANK at idle (without the cover the engine will stay too cold).

Then start the engine and let it run rich at full throttle with or without the cover (depending on temp):
2-tanks at 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 Break-in in the car for about 2 more tanks tuning your needles for max power and you are then ready to go.

With the engine at full-throttle, you are sure that the idle needle is not in front of the spray bar, so you are running the engine really on the setting of the main-needle and you’re also sure the engine will run rich. Also more fuel/air will go through the engine at full throttle so there’s better lubrication.
DON’T FORGET TO COOL-OFF YOUR ENGINE COMPLETELY AFTER EVERY TANK.

Rody Roem
RB Concept Engines

fastharry™

iTrader: (4)

thats all well and good....but getting the engine to flame out..and then turning in 1/4 turn..and then running the WOT(..according to Josh's method)..does not yield temps in the 190 to 200 range.....

so maybe I should lean it out a tad..get the temp to 200..an then run it 3 tanks?....