heat cycle break-in!

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4x4

Well-Known Member
Messages
811
Location
england
here is the heat cycle break-in.
these instructions are helping me to break in my engine.

it is from: http://www.johnnycoolguy.com/JCGR/main/tech_break-in.html

ENGINE BREAK-IN LIKE THE PROS

This was copied from a post by STEPHEN BESS on the "Starting Grid" message board as he tried to help another member get more life and performance out of his OS motor. This break-in method should apply to virtually any ABC hobby nitro engine (except for ringed engines).

If you are still idling at least a tank through during break-in, you're using the old-school accepted method (still works well for some!) but it's not the method that the top engine guys (Ron Paris, Dennis Richey, Rody Roem, Michael Salven are just a few I've spoken personally with about this) recommend anymore.

From the very 1st time you start your engine, plop the car on the ground & begin running it in a parking lot in 2-3 minute intervals, tuned only *slightly rich* getting the temps up in the 200F range on a normal day. Every 2-3 minutes, shut the engine down & let it cool completely with the piston at BDC, and then fire it back up; continue this cycle until you've run 15 min or so, and then bump up to 3-4 minute intervals. Vary the RPM and don't be afraid to get the temps in the 200's. What you want is heat cycling of the components without the incredible stress that comes with breaking an engine in when it's overly rich & cold. After cycling the engine in this mannerfor about 20-25 total minutes, it'll be ready for the track and race tuning. I realize this method goes against the old-school "idle on the box" routine, but you'll be amazed once you've completed this break-in routine, your OS will still have amazing pinch w/out sticking at the top AND your OS's compression will last far longer than it will with the "old school" method.

You say you run the engine at "factory settings" for the first FIVE tanks? That alone causes lots of stress, as the factory OS settings are very rich on every OS I've ever owned or tuned. The piston & sleeve haven't expanded to operating temps, and every time the engine turns over, the piston slams into the pinch zone at TDC. The not-so-surprising result can be a cracked con-rod at the crank pin--that's where the majority of the stresses occur as the engine turns over. I've only heard of about 6-8 OS engines breaking con-rods, and they're ALWAYS during the first gallon...and almost every time it's because the guys have performed the break-in procedure you described. Doesn't seem like a mystery as to why it's happening. Drawing out the break-in routine really stresses the engine & actually wears away compression along the way. This method I've outlined will feel weird at every step, but after you try it once, you'll notice a big difference in your engine's performance & lifespan.

Hope this helps; give this break-in method a shot--you have nothing to gain except longer life & more power :)


hope this helps
4x4
 
anyone have any comments? is it good for people who want to break there engine in this way.
thanks 4x4
 
posted this awhile ago. (well copied over from revo-world)

its a great breakin procedure, everything written in it makes sense and breaking an engine in takes alot less time.
 
thanks for the comments its working well for my new engine so far and i wish you luck when you break in your next engine -savage x-.
thanks again 4x4
 
I have a question, actually. How the heck do you know when you're piston is at BDC? Are you supposed to take out the glow plug every time and peek down through or what?
 
Mark your flywheel after you first install it so you have a line to go by for BDC
 
Excellent tip, JT. For the guys that preffer roto-starts, that works great.
 

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