RCU Forums - break in

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I just got my new 3.3 jato racing engine so do i use the heat cycling to break it in sounds like a good plan?

Do this:
[link=http://www.cooperfuels.com/Break-in.htm]ABC Break-in[/link]

so do i put it on the ground while i break it in or let it free idle

Read the instructions carefully. It says to drive your car around.

Quote:

ORIGINAL: Fuelman

Do this:
[link=http://www.cooperfuels.com/Break-in.htm]ABC Break-in[/link]

hold your engine wide open? are you kidding me? that is the worse break-in guide i have ever read. Use the heat cycle...

Those videos are not too bad. I think that step (video 18 out of 21) does a fantastic job of describing how to properly tune a car/truck/buggy engine, regardless of brand name.

For your information guys, ALWAYS check the factory needle settings to insure they are at the factory recommended starting positions before ever trying to start the engine. Also keep in mind that the factory settings do not always give you the best begining mixture setting since they are based upon the fuel the factory is using, altitude, etc..... and are only a very rich starting point.

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hold your engine wide open? are you kidding me?
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Where does it say to hold your engine at wide open throttle?
this is what it says on my web site:

I am a firm believer in achieving maximum engine longevity. I have every interest in teaching you how to have the longest lasting engine since I make fuel and broken/ worn out engines do not burn fuel!! I do not make or sell engine parts and have no interest in you prematurely wearing out your engine just to sell parts. One critical measure we can all take with a new ABC type engine to break it in properly and tune it properly. The other critical measure is to use a quality fuel containing some castor oil in it with a percentage of nitro that the manufacturer recommends.

Break-in of an ABC-type engine is quick and simple and generally takes less than a quart of fuel on most average .40 to .60 size two strokes, a little less for smaller ones like the car engines and more for larger engines.

1st- Partially disassemble the engine, at least remove the head and backplate to inspect the inside for shavings, flashing or debris. Flush it out good with some old fuel to get any fine metallic dust particles left over from the machining process, out of the engine. You would be surprised at how much metallic dust can be flushed out of a new engine, do the flush in an old white cool-whip container and you will see for yourself!

2nd- Install your engine in the car, plane or engine run stand, fill the tank full of fuel and then set all the needle settings to what the initial settings are in the owners manual. Both the low speed and high speed settings in the manual are a starting point. If the engine has an exceptionally tight pinch, making it hard to turn over, you may want to heat up the cylinder head with a heat gun or other means to relieve enough pinch to get it started.

3rd- Fire it up! Toss it on the ground if its a car and make a couple brief medium throttle passes to bring it up to temp. On a plane, just take it to wide open then adjust so it breaks into a clean two-stroke. In a car, once warmed up, bring the engine up to brief full throttle pass and adjust the high speed needle so that the engine has just begun to break into a clean two-stroke running condition (no longer sputtering or missing). Do not lean it out to maximum rpm's, on either a plane or car!

4th- If in a plane, just let it run wide open for 2 to 3 minutes. If its in a car, run it around on the ground using the full range of throttle with brief amounts of full throttle. Do this on a hard surface rather than grass to minimize a heavy load on the engine, like the planes, run it around 2 to 3 minutes.

5th- After the initial 2 to 3 minute run, shut it down and let it cool completely before doing it again. DO NOT force the engine to cool by pouring alcohol or fuel over it, let it cool naturally.

6th- After its cooled down, fire it up again and do the same thing, Just run it a little harder this time. Make sure the high speed needle setting is still allowing it to break into a good clean 2-stroke run, you may have to lean it slightly. Now you want to start paying attention to the low speed needle and start adjusting for crisp throttle response off idle. Shut it down after 2 to 3 minutes of running it around and let it cool.

7th- Again, after a complete cool down, do it again, running it even harder. Now you need to start leaning into the high speed needle a little bit closer to optimum running and get the low speed needle closer to a good clean crisp response. Shut it down after 2 to 3 minutes of running and let it cool completely. Repeat the 7th step one or two more times.

8th- The engine is as broken is as its going to get by this point. Fill the tank up to about half full then start getting the idle needle and throttle stop set to where it will idle for 15 or so seconds without quitting or loading up when you punch it. Set the high speed needle so it runs cleanly without sagging when wide open. If it gets that way, richen it up. As the engine accumulates more run time the tune will change slightly, thats normal, just be aware of it.

As long as you do not run your ABC Type engine too cold (rich) or too hot (lean) you will have an engine that will perform the way it is designed to and have a nice long healthy life.

There is no need to worry about what the engine temp is since that is dependent on so many variables it is not even worth discussing in a break-in or tuning article. Just do not worry about it, if its running crisp and clean without sagging or fading at full throttle it is not too lean and therefore not too hot. If the transition off idle is crisp and clean it is not too rich or too lean. Either case, the temp is a meaningless break-in and tuning tool.

Hey desicop can i use the videos for the 3.3 also

Running WOT during break in is the norm for airplane engines. I have seen some VERY experienced boat racers recommend the same method for running in boat engines. I generally use the method, I used it on my RB. Another guy has an RB at my club and mine is the sronger engine.

Bringing it to high speed gets the rod bushings seated and that is the most critical clearance in that engine. Once up to temp, you are not stressing the rod through excessive piston pinch. Running them hard but wisely is the most beneficial to an ABC two stroke.

The thing with planes and boat engines is that running a plane on the ground allows you to adjust the needles easily. Every boat I've seen was run with a mixture control on the third channel although freewheeling baseline needle settings are used to get it in the water.
With a car/buggy engine, you can freewheel the first startup and take it wide open long enough to get the high speed needle set to a clean two stroke, then toss it on the ground.
This is what I do, but recommending that does not go over too well in the car crowd. It is actually easier on the engine freewheeling it than loading it with driving but it is easier to tune with the audio and visual senses than it is with audio alone and car engines are real easy to get too lean or too rich because of the misconception that temp is used as a mixture indicator.

With a brand new ABC type engine their are two things you should never do. The first is never turn it through the pinch because they only have a very light preservative oil in them which isn't designed to be a lubricating oil so there's a good chance of damaging the piston if it's forced through the pinch. The second thing is that even with proper lubricating oil in it (from the fuel or even raw oil) never turn it slowly through the pinch because this will squeeze out the oil and you're back to possible piston damage. Once an engine is running, even at idle, there's simply not enough time for oil to get squeezed out at the pinch.

Full throttle and full load is the best way to run in an engine mainly because that's when it has the highest fuel consumption. High fuel consumption means the highest flow of oil through the engine and it needs this oil for protection. I'd strongly advise using a fuel with at least some castor for running in even if you have to add it yourself. With a plane engine they're running with a continuous high load so it's easy to set the mixture but a car (or boat) has to be done by trial and error so setting initially to know it's too rich is a lot safer than too lean. Too rich (full throttle) won't hurt the engine in the slightest, in fact I found that too rich (4 stroking) won't even let the piston run in. The rod bushes will run in beautifully though.

The best initial setting is just about what Fuelman recommended with the engine just barely breaking out of 4 stroke and running in a 2 stroke. The occasional misfire just lets you know the mixture is still correct. Every few minutes after that then you can slowly lean out the mixture maybe a click at a time to gradually build up the heat over the next 20 minutes or so. Forget about actual temperatures, they don't mean anything.

Or you could use the traxxas break in process that they recommend. It is there engines they would know about their engines.