Is it a very bad idea to break-in/run a nitro engine in freezing temperatures? Right now the weather around my place is about -15 to -20 degrees, Celcius, or about 5 to -5 Farenheit. I know some of you are probably going to tell me I'm an idiot for trying to run in these temperatures and that I should wait until warmer weather, but warmer weather is months away. If running my engines in this weather means I need to replace the pistion/sleeve come summer, so be it, the enjoyment I get out of it is well worth it to me.

Anyway, I finally replaced the ancient and crappy Pro .15 in my TMaxx with an OS .18 CV-RX. I let it idle 1 tank indoors, just because I didn't want to take it straight outside. The second tank I idled sitting inside my door, but with the door open to let fumes out. After that, I took it outside, and started running it gently up and down the sidewalk, no WOT. For the fourth tank, I started giving it some short blips of throttle, but never to WOT.

I have been running it with the body on to try and keep the engine warmer, and I have the cuff from a wool sock that I just stretch over the cooling head, in an attempt to keep it warm. I do not have a temp gun at this point, but my "home test" is seeing if small bits of snow boil off the head, it must be around 220F

Now, the engine seems to be going fine so far, around 6-7 tanks through including the first 2 idled ones. There is still a slight pinch if I try to rotate the flywheel, more than just compression, so I know it's not fully broken in. It's very difficult for me to try and break these in/tune them because I only got into the hobby in October, and don't have a lot of experience. The temps I'm running in make my carb settings drastically different than typical, so I don't really know if I'm being harmful to the engines.

I'm posting this because I'll be putting the finishing touches on my Nemesis soon, and will need to break it in. I guess if I made a mistake on the OS, I'd like to know so that I don't make the same mistake with the 7.7. Is there anyone else here that runs nitro engines in very low temperatures, and can you give me any hints that you've picked up? I feel like I'm flying blind here, trying to tune these myself. I've already asked my LHS's and they all tell me I shouldn't be running in this weather, but it's too fun not to.

That, and my TMaxx is extraordinarily clean, not a speck of dirt anywhere. There's some advantages to driving around in the snow [8D]

Thanks for any help, sorry for the long post.

i dont tune to temp. but i use my temp gun alot when breaking in a engine its a good investment to have. i broke in an engine when it was cold and it seems to be doing just fine

you will really need to watch temps and make sure you are not lean, you have to have temps in the 180-240F range all the time the enigne is running, you will have to wrap the head with alum foil to keep the enigne warm, and heat the before starting, if your enigne is running cold don't lean it to wram it up, just keep wraping the head.

and don't let the engine cool down to below 60F when its off.

I think most would not recommend breaking them in with it so cold..

Engine can be running at 220 and be running to lean,

I think if you wrapped the head in something to keep the temp up without having to over lean it.

But I've never broke and engine in with it that cold, coldest i've run is 35 degrees..
I should of wrapped the head cause i couldn't get it to temp without overly leaning it,

ive broken in 2 engines in snowing conditions and both seem to be doing just fine like all my other engines. i warm the engines with a hair dryer then i use a sock to keep the engine temps up and run them.

I wouldn't do it.
Not for any fear for the engine. With the proper preparations and precautions the engine will do fine.
No, I wouldn't do it because I don't like the cold - and you will get cold doing it.
There's a reason I moved from Minnesota to the deep south. In thirty years it's only gotten into the teens a few times and into the single digits only one time that I can remember.

haha i never went below 40 til i was 16. cali weather was great

I've actually started wearing a scarf around my left hand/TX. I can't wear my glove because I wouldn't be able to use the throttle. So, I wrap a scarf around the whole thing, leaving the steering knob and antenna sticking out. That, and warm clothing, and I'm fine. Until I did that I'd have to go in when my left hand got numb.

thats a trooper!

As long as you can keep the engine easily at operating temp without leaning it out to achieve good operating temps, you'll be fine. I wrap some tin foil around the head then rubber band it on, then a sock when its that cold. But, that's just me.

I always carry aluminum foil in my tool box so I can wrap the cooling heads. I usually do it when temperatures get below around 20F. Even when wrapped with foil, I have never had a problem with overheating. Of course, I do check the temp more often when they're wrapped.

My brother and I broke in his OS 18 CVR a couple weeks ago and it was 11F (about -12C). Everything went well, but it was freakin cold out there We didn't wrap the head, but if it had been as cold as you're talking about we would have. Actually, if it was that cold we would be waiting for spring

Oh, I have been running nitros for about 15 years and have never used a temp gun. I have nothing against them, but don't see the need to be so precise when bashing. All of my engines run tip top.

Thanks for all the great info, looks like I'll be wrapping my engine in foil. I haven't been running the Tmaxx lately, there's been a cold snap here, temperatures are around -35C to -46C, which is too cold for me. I did try to take the truck out, and it ran fine (started first pull!). I just couldn't take the cold, and on top of that the snow has been drifting, is really powdery and light. The Tmaxx just sinks in. Guess I'll have to wait a week or two