RC Nitro bearing trouble

[EvhCo]

The rear bearing on my Super Tigre seems to hit the dust. A few days ago I left the engine without ARO and the next day, the inside of the crankcase was SWARMED with rust. Fast forward, I got rid of all the rust, but the rear bearing makes a small "dragging" sound. It's still smooth, but I don't wanna risk it.
Are there specific bearings I need to place in the engine (apart from the size)? I've seen some shady ceramic bearings, would those do the trick, asuming they fit?

 

[WoodiE]

@EvhCo where the heck did you store this engine that it immediately filled with rust after one evening?!? ?

For bearings I use FastEddyBearings and recommend them. However Boca and Avid are also good trustworthy brands as well.

 

[D3MON]

@EvhCo where the heck did you store this engine that it immediately filled with rust after one evening?!? ?

For bearings I use FastEddyBearings and recommend them. However Boca and Avid are also good trustworthy brands as well.

+1 to this, i actually just received some fast eddy bearings for my engine rebuild project, i am very pleased with them. i used the double sealed front end bearing, XXX2R-SC (replace the XXX with the bearing size that you are needing) was the bearing type that i used, then i removed the bearing seal that goes inwards towards the crank.
also the "rear" bearing is the one in the middle of the crankshaft, the "front" one is the one closest to the flywheel.
i will say that i have had luck with boca bearings as well, but i had heard so much about fast eddy and wanted to go that route.
boca bearings have a really good fitment guide to get the correct size.
that is kind of troublesome that you had rust in just a few days, received a motor that had sat for about a year without ARO and had very little rust inside.

 

[EvhCo]

One thing I noticed is that there was a persistent exhaust smell around the engine HOURS after I shut it off. I've left if without after run care before and this never happened, but I'm surely not missing a step from now on.
The bearing makes a soft noise that is inaudible unless I stick my ear on the crankcase. It's very smooth, however. Does it need replacing?

 

[D3MON]

given that they are pretty cheap, i would go ahead and have one ordered, have you tried dripping a bit of fuel on the inside of it (from the backside of the case)? and roll it over to see if it clears up? may be able to flush it out with brake cleaner or some alcohol. make sure all cleaners have had a chance to dissipate and to pre lube it with fuel before closing it back up, you never want dry bearings.
the smell is probably from the fuel/oil in the pipe after its done running, and is pretty normal i think.

found a pretty nifty way for bearing removal and install here:

id probably order the new bearings, but IMO should be fine until then.
never know the bearing might last a few days, or it could last years, tis the luck of the RC nitro gods.
my $0.02

 

[EvhCo]

the smell is probably from the fuel/oil in the pipe after its done running, and is pretty normal i think.

Uh, okay, I know I'm gonna get lectured for this one, but...
I DON'T HAVE A PIPE!
Yet, at least. The tank is mounted higher than the carburetor, and that's how it's getting the fuel. Runs as rich as I need it to. I personally love the super loud sound, but I don't wanna wake the whole city up when I'm out for a run, so I'm eventually gonna get a pipe after I make sure nothing else is left to replace on the engine.

have you tried dripping a bit of fuel on the inside of it (from the backside of the case)? and roll it over to see if it clears up? may be able to flush it out with brake cleaner or some alcohol. make sure all cleaners have had a chance to dissipate and to pre lube it with fuel before closing it back up, you never want dry bearings.

I've tried pouring some fresh fuel down the bearing, and it's still sounding. I'll go ahead and try with the brake cleaner eventually.
After everything's done, I'll order two bearings (gonna replace the front one too while I'm at it), and in the mean time I'll put it together and try to run it like it is, see how's the bearing acting. The stories of bad bearings destroying engines kinda scared me a little, so I ain't gonna test my luck.
Are the rubber-sealed ceramic bearings good in an engine? Does the crankshaft area get hot enough to worry about the rubber seals?

 

[D3MON]

the center (rear) bearing typically looks something similar to this: https://www.fasteddybearings.com/13x24x6-bearings/
(this may not be your bearing! reference only!!!) and is designed for being the bearing in question. for the front one, i ended up with a ceramic double shielded as above and removed a seal, I'm guessing this is a plane engine correct? i believe that those use metal shielded bearings in closer to the crank. if its a car you want a rubber shielded bearing. with the shield on the outside only to allow fuel/oil to lubricate it from the inside.
i would highly recommend getting a pipe, not even for fuel delivery, but for backpressure of the engine. its hard on the engines to run with no backpressure.

 

[EvhCo]

It's a car engine actually. A G27 CX.
I'll get the engine together soon, and post a video of it running so maybe you can hear or see if there's anything that needs urgent replacement. Thanks a lot for your help! Much appreciated.

 

[D3MON]

ahh ok, for some reason i hear super tiger i think of plane engines.
https://www.ebay.com/p/OFNA-HYPER-7-TQ-Pro-Pipe-Header-Hobao-Oh29/2256036996?iid=303076049739
here is a pipe that is very cheap that also sounds very good, i just put one on my MGT .21, and seems to compliment the power band well.