Real Newbie question here but does this method work for big block, truggy motors? I have read through the posting and I only see references to .21 and .12 sized motors. Thanks.

So where can I find this procedure?? Is there a link? dumb question....i know..

THIS IS IT
 

In the area of engine break-in, there are several different procedures that have been used over the years. Different manufactures, top drivers, and hobby store experts all vary in their opinion as to which is best. Over the past 10+ years of nitro racing I have found this procedure to give me good results in both areas of on-track performance as well as reliability.

Install the new engine into your chassis complete with clutch and ready to go as if you were going to race. Take a screwdriver, glow igniter, starter box, and a full bottle of fuel to a remote area where you won't annoy anyone with a running engine. Start your engine and allow it to warm up with several short ½ throttle “blips”. Once your engine has some temperature in it you can begin the break-in process. Start by opening the top end needle 1 full turn. Open the carburetor to full throttle and hold it there. Open the top end needle until the engine flames out. From here, close the top end needle ¼ turn and restart the engine again running it at full throttle. Run the engine full throttle for 3 tanks and shut the engine down.

Allow the engine to cool for 15-30 minutes. Once the engine has cooled down, run through the same process again for two additional tanks. On the third tank close the top end needle by ¼ of a turn. Instead of holding the engine at full throttle, start using the throttle by doing 2-3 second bursts of full throttle. Once you have done this for ½ of the tank close the top end needle another ¼ of a turn and continue throttling the engine. Continue closing the top end needle ¼ turn per every ½ tank of fuel. Do this until you have run a grand total of 8 tanks through your engine and then shut the engine down.

Allow the engine to cool for 15-30 minutes and then you are ready to hit the race track. Drive two tanks rich around the track slowly closing the top end needle sneaking up on that perfect mixture. At the end of the second tank your engine should be tuned to race speed. This will give you a total of 10 tanks of fuel through your engine before you really start to lean the mixture for ultimate power.

The reasoning behind this break-in procedure is that there is always a large volume of fuel flowing through the engine. Large volume of fuel means plenty of oil and lubrication for the break in process. This also helps flush out any burrs or small pieces of material that may have been left over from the manufacturing of the engine. Also, the engine has a load placed on it by trying to cycle all of the fuel through it – somewhat similar to the load that you will put on it out on the track when you try to power your car around the track. Last, the engine is broke in with rpm – if you break the engine in at idle then you will not be seating the piston, sleeve, and connecting rod at anywhere near the rpm that it will have to be ready for out on the race track.

This is the procedure that I have used with good success over the years of nitro racing. When I've hurried the break-in process I have had some engines last 30 minutes to 4 hours of racing. When I've taken my time and run through this process I've run engines as long as 16 hours of racing!! Yep, same piston and sleeve!!!! Be patient and have fun!!

Good Luck!!
Josh Cyrul
CEFX

CEFX.net , and if you think his break-in procedures are good check out his other articles there. Some great info!!!!!

Yes

Thanks Nitrojunkie & Artificial-I, I really appreciate it!

glad i could help :)

I am about to try this method on my new IDM Evo 3 (Picco) engine. I'll let you know how it works out.

one thing it dont say in the instructions and i highly reccomend is use a hair dryer or heat gun to preheat the engine up will make it a lot easyer to start for the first time and a lot less stress on the conrod

and every time you let it cool down make sure the piston is at bottem dead center

I'm starting the Cyrul break in and I've got a few questions. My motor is a TZ 12.

First, when I'm opening up the HSN the engine will bog (4 stroking I think?) and I have to keep turning quite a bit to actually flame out. Subsequently, I have to turn the HSN back more than just 1/4 turn to get it to not 4 stroke. I take it that it's not critical exactly how far I turn back the HSN but that the motor is running properly at WOT.

Next, I know I'm not supposed to worry too much about about the temp, but at the same time I know that cycling the motor without enough heat is a bad for the engine. When I back out the HSN just to the point that it runs without flaming out it's still pushing so much fuel through the engine that it doesn't get very hot. Probably in the 130 to 150 degree range. Shouldn't I lean out the HSN some more to bring up the temp so I'm avoiding damage? What temp would be safe for this stage (the first three tanks) of the break in.

This is how it should sound.

http://www.pro-hobby.net/video/r40_c...od_breakin.wmv

Dont try to match it perfectly to the sound but it should be similiar , try to make it as rich as possible without shutting down.

That video was super helpful. I watched it last night and was able to make the motor run in a similar fashion. Thanks!

What about the temperature though? I can get it to run like the video while varying the HSN through a small range. The temp varies depending on the HSN setting. If I can run the motor like the video and get the motor hotter isn't that best?

put some aluminum foil over the head to help keep temps up. i machined a spare head down so it only has 3 fins left.

sounds like you have a sedan, so also what you could do is to just get the wheels barely spinning and hold one rear wheel to put some load on the engine and help bring temps up. keep it over 160F at all times even if you have to hold a hairdryer on it the entire time.... you may need a second person to help.

That wouldnt be so great for the clutch of diffs. Cyrul states to make sure the wheels arent spinning , therefore no clutch engagement.

The fuel is putting load on the engine and the rpms arent so high so this really wouldnt be needed either way.

At least thats my thoughts on it.

You can always go in and out of the cyrul mode. I did this , I would then let the motor idle and idling on a leaner state it would heat the motor up. Then I would return to the cyrul mode and back and forth. This is how I heat cycled my motor.