Break-In Worries

[KROGOTH]

Ok. I just got my new O.S. .21TM, and after spending yesterday prepping it I started break in today. Finished tank 1 recently. I planned on heat cycling it originally, but I was apparently running it ridiculously rich for that first tank and it was hard to get the temp above 150 degrees. I'm thinking the high speed needle needs leaned out, but I'm really nervous about this.

I'm trying to break this engine right and take better care of it than I did my 3.3.

Anyone have any advice on how I should proceed?

 

[weezracen]

I would use traxxas brake in and just keep a eye on my temps make sure it gets hot enough. When you let your mill cool down I would also make sure that it is at bdc (bottom dead center). A good way to find bdc is to take out your glow plug and turn the fly wheel until the piston goes all the way down then make a referance mark on the fly and chassis. Take your time and I like to baby mine for a few more tanks after I think it is broke in. Just my 2 cents tho.

 

[KROGOTH]

Yeah on this engine I made sure to mark BDC on my flywheel when i installed the flywheel. I've learned alot since I broke in my 3.3, but I want to take proper care of this engine.

 

[Gee]

You can use a sock or alum foil (wrap around the head) to help get the temp up fast during the break in process. Probably better to do that then have it to lean at first. Need it rich to lub the parts and relive the stress added during the break in. Also preheating the engine before starting it does help vs starting it from room temps. It important to get the temp up fast during the first break in.

 

[KROGOTH]

Tried using a sock. You dont understand though, lol. My motor was dumping fuel out the exhaust. I should take a pick of the dark spot where I ran the first tank. Even with a blow dryer and a sock on the engine, it wouldnt go above 165.

On my second tank I got it to run at around 190-210 pretty consistently. This afternoon I may do a tank of just heat cycling since I messed it up last night.

 

[Gee]

I got a few of those stains on my bench out back. I did have that problem with my lpr 28. Couldn't get the temps up. Got too concern about the temp and next thing I know I had a $175 paper weight. Well not really but was close enough. Leaned it out too much and well the rest is a whole thread in itself. I just had it repinched and going to try it again. I know what it is like to be cautious about having one too lean. I've read that 210 is an acceptable temp for break in. If that what you get next time I wouldn't lean it out any farther. The oil helps reduce the breaking stress but so does getting it up to the right temp. Oh, yeah next time tell us you already tried the sock. lol

 

[KROGOTH]

I'm just going to try and straight up heat cycle it for a couple tanks and then just start babying it.

Gone through 3/4 of a tank already. Getting the temp up to 200 and then keeping it there a few minutes before stopping the motor, putting the piston BDC and letting it cool and repeating. Its still running very rich, so it seems to be taking a lil while to get my temps up, and it bogs down if I give it more than half throttle, so yeah. I'm nervous as hell and hope I'm doing it right with this engine.

 

[traxxas t-maxx]

So about what temps. do you want to be running because when I get my new diff. I have to break my new 2.5 in?

 

[KROGOTH]

Alrighty, heat cycled my engine for roughly 25 minutes of running time (i.e. I'm not counting the time it spent cooling off). I had half a tank left so for a bit I drove it and tried to get it at least slightly in tune. Was giving good response in the 240-250 range but I feel this was too hot so I started richening it back up. Even though break in is done I want to run it rich and take it easy. Thats my plan so far.

My big question here and now is, how do you know you're done breaking your engine in?

Alrighty, heat cycled my engine for roughly 25 minutes of running time (i.e. I'm not counting the time it spent cooling off). I had half a tank left so for a bit I drove it and tried to get it at least slightly in tune. Was giving good response in the 240-250 range but I feel this was too hot so I started richening it back up. Even though break in is done I want to run it rich and take it easy. Thats my plan so far.

My big question here and now is, how do you know you're done breaking your engine in?

 

[blckrevo33]

i just rebuilt my 3.3 and broke it in. i too had a hrd time getting the temps up finally about the 5th tank or so i had pretty consistent temps 210-250ish. i ran 11 tanks through following traxxas method after the 9th tank i started messing around and running it good and now my temps stay between 225-260 and it screams. i still knida baby it a little more than most people but my last 3.3 lasted three yrs.it just lost pinch never broke. just make sure you put it at bdc after it shuts off.