Has any one used the heat cycling method. I have been running nitro for 10 years and have always used the factory directions. I read all the top motor guys start by running the motor at a slightly rich setting on the ground for 2-3 minutes then shutting it down with the piston at BDC and letting it cool, start it up and run it again for 2-3 minutes, keep doing this until you've run 15 min on the motor. Then jump it up to 3-4 min until you have 20-25 min. on the motor and dont be afraid to get the motor over 200 degrees before letting it cool because the motor is going to heat cycle. After 20-25 min tune to race.

The sticky link, http://www.rcuniverse.com/forum/m_5517128/tm.htm, is probably the best description of heat cycling for the initial engine break-in. I highly recommend this link and not only that, it is full of many useful tips concerning tuning and engine care as well.

As for the break-in of a brand new engine, always bear in mind taht this is only the initial break-in. Many engines are not fully broken in yuntil about the half gallon mark, and some of the higher performance engine may need as much as a full gallon befoer tehy are broken in. The initial break-in is meant to primarily wear teh piston into the sleeve and have those match each other for a better compression seal. In many cases, the pinch is still quite strong intil the half gallon or full gallon mark, so the engine might have gone through the initial break-in but is not fully broken in.

When breaking in any engine and even up until when the engine is fully broken in, I consider it an absolute muct to preheat th engin before evn tring to start it.

I have been heat cycling my engines for a while. I am in the process of doing it to a new engine right now. I am a true believer in it, but not everybody likes or uses this method.

That is true since it is moer involved. As a matter of fact, many engine owner's manuals tell to idle the engine with the wheels off the gound and at WAY to rich a setting. This will intially break-in the engine, but such a cold break in eats too much material off of the piston and sleeve thus reducing their logevity potential.

Just keep it at 200F and idling will be fine.

I'm done using the heat cycle method and run 5min instead of the 2-3min

You need the engine temp at least 210 to start breaking it in. You can run your engine almost as hot as you want as long as you're not lean.

I do the same, I'll le the engine temps get up to 250-260 as long as I have good smoke. After 5 minutes I shut her down and put the piston at BDC and let it cool then repeat.

Ideling through the first couple of tanks and not letting the engine temps to get above 210-220 degrees will put stress on the con-rod and may reduce the engines logevity.

i get em over 200 and run the whole tank, keep temps between 200 and 220, empty the tank, BDC, cool and repeat

Idling will not put any stress on the rod, but rather taper the piston size at the improper temperature. So when break in is finished and you lean out, you experience "blow-by" and a lack of compression at proper operating temps[8D]

If your engine has a lot of pinch and you don't preheat the engine and maintain the temps over 200 degrees F, you can damage the con-rod.

Ah yes! Forgot about that[)]