breaking in?

[Chuteboxe]

I just bought a savage 25 couple days ago, i have a 4.6 but desided to keep that for racing at the track, i wanted somethin to bash with. I desided to give breakin the 25 a try since i let the guy at the hobby shop do my 4.6. I let it idle through 1 1/2 tanks of fuel, then the next tank and half i put it on the ground and drove it at 1/4 throttle, and starting leaning it out slowley and gave it a couple hits of the throttle, ppl have been tellin me diff things, LHS said one thing, the book says another, and one guy was sayin not to break it in like that cause these things are tough and want to be run hot at first to get used to it, he said its all BS and there are so many myths out there bout breaking in, i dont kno who to beleave so i took it back to the hobby shop and left it up to him, my question is do u think ive done any serious damage to it?, it dident sound bad when i was runnin it and the guy at my LHS said it should be fine?

Thanks, Gino

[one]

Everyone has their own methods, but the reality is that you only have one objective goal.........get the engine to normal operating temprature every time. It cannot achieve that when idling. It can achieve it during 1/4 throttle bursts for 2 seconds however. Never rev the engine past halfway for the first 2 tanks, never "max it out" until after the 4th tank.

That's how to break an engine in.

If the engine does not get to proper temprature during break in, it will not expand and contract correctly and therefore will always be "tight" inside. This causes friction leading to slower performance and premature wear greatly increases. If it is brought to proper temprature, it will "set" correctly as the piston and sleeve contract and expand as they should.

It's also good practice to rotate the piston to the bottom of the cylinder for at least the first 5 tanks after runs to eliminate it cooling at the top and creating a larger gap at the top of the piston and loosing compression. After 5 tanks the piston and sleeve will be pretty much "set" and it won't matter, though some do forever just it to be safe.

[Chuteboxe]

thanks one, could u tell me wat the proper temp is for the savage 25 when breakin in?
the guy at my shop said it shouldent be brought passed 180F 190F or so and then shut it off and let it cool down, start it up and let it run untill it hits that temp and shut it off do that repeatly for 3 or so tanks

[Duster_360]

Usually, everbody using the heat cycling style of breakin talks about getting the engine up to 200F. This is what the method one is talking about is called. You are trying to get the piston/sleeve to a high enough temp (200F) so the correct amount of expansion takes place allowing the piston and the sleeve to wear in together or mate together. It is important to return the piston to bottom dead cylinder out of the pinch zone while it cools. And you should allow it to cool completely down at least for the 1st one ot two cycles. If you allow it to cool while the piston is in the pinch zone, it can get stuck and in freeing the piston, you'll have caused premature wear that costs you some engine life.

Your hobby shop guy is on the right track. Don't feel bad, I idled my 1st tank on my 1st rc not knowing any better. I don't think you've done any serious damage, my 1st lasted 3 gallons in spite of doing it "wrong".