FabianT5

Hi,

i've been battling with my brand new Losi 350 for a while now and made a devastating discovery last night. I found that multiple balls of the large crankshaft bearing have shattered and the pieces of the balls went through the engine and destroyed it.
I had done a very careful break-in (following the most common suggestions) but never got the engine to run right...blew plugs and engine seemed to run too rich at times and too lean at other times in the same exact run. Thought i had airleaks and checked and sealed everything which is when i discovered this damage.

What leads to this? Did anyone ever see anything like it? Again, engine was brand-new and i was in the process of dialing it in after break-in. I've done some very carefully, monitoring engine temp, sound, smoke, etc.

I have another car (8ight T) with an also brand new Losi 454 engine that i haven't touched yet and won't until i know what caused the failure on the 350.

I hope the pictures show what happened.

Thanks for your help.

pickle311

iTrader: (31)

Ouch, that's bad. I would bet on a defective bearing. Those aren't the most reliable engines, but usually do pretty good for a few gallons.

Roelof

Do not try to find a reason, you will never know. Could be left over dirt from production, a bad ball or a bad placing of the bearing. Keep in mind that an unbalance in the clutch or even a bad clutch bearing can have an effect on the engine main bearing.

If the engine was new, try to get warranty.

PlanB

Wow... I would never expect that much amount of deformation just from a piece of metal. Try to get warranty solution.

1stPlaceAllDay

looks ok to me :-P

B3nno810

iTrader: (3)

Thats crap, i would bet on a defective bearing. I have found the losi engines to be very hit and miss tbh. Money would be better spent on a better, more reliable brand. Also unfortunately you will be hard pressed to get warranty, as most warranties are voided on nitro engines the second you run any through it.

B3nno810

iTrader: (3)

Why not? Nitro engines run at very high rpm's. They are also made out of light and softer materials than a full scale engine. Ever seen a full scale engine that has dropped a valve or spun main/big end bearings?

PlanB

You are right, but two stroke engines logically have better chance to clean itself. Somehow that metal piece just stuck in the chamber. I will be more careful about particules.

FabianT5

Thanks for all your replies. I will call them but am not so concerned about replacing the engine.
I was more concerned that this happened because I did something wrong. So from your replies, it looks like this is something that usually doesn't happen.
As for PlanB's comment: I found a piece of one of the balls stuck in the piston...that gives you an idea of the hardness difference between soft piston/sleeve and hardened bearing balls.

@ B3nno810: I know this might derail this thread, but what would be a good alternative (as I am now in the market for a new engine again)? I'm not racing, and don't need max. power. I'm a busy dad, that bashes every now and then. Got the Losi 8ight B and T because they seem very durable. Same i want from the engines in them. Durable, easy to tune, don't need crazy power.

Thanks again all for your insight, it helped me classify this failure.

pickle311

iTrader: (31)

Look for a Novarossi based engine. There are numerous rebranded Novarossis out there at great prices. The Fusion X3 is a great engine, plenty of power, and high end reliability for less than $150. Same with the Nova Elite 5. You can find it for $130.

PlanB

My first .21 engine is Novarossi Elite 5. I can define myself as newbie and this engine took so much abuse from me and still running good.

Tzicul

You just had bad luck. I'm now in process of rebuilding my 454 because I couldn't tune it anymore and found that front bearing seal was gone and the temperature goes high after 2-3 minutes of running. Lucky me, when I opened the engine I found that rear bearing had maybe 1 mm transversal play and the conrod was touching the crankcase. Probably very soon might have happen to me what happen to you. But I've got thru mine maybe 6-8 gallons of fuel. On the other hand, i just destroyed my GXR21 but I have no idea how, I just found that the piston has some deep scratches. Never run it without the air filter, the bearings was just fine, no loose parts. The only thing that came my mind is a broken plug, but... I don't know for sure.

token

You should see my Orion engine after a conrod popped... It was bad....

B3nno810

iTrader: (3)

An OS speed spec 2 will be a good upgrade. They are fairly well priced atm as theyre an older engine. They just keep giving and giving. Very reliable, holds a tune very well and has plenty of power.

A Novarossi mid range engine will also do the trick, could even drop a legend 4 into it.

Another alternative is the Fusion X4 for the buggy and Fusion x7 for the truck. Plenty of power, they seem to be very reliable engines and quite durable also.

Micah78

Thankfully your engine was just a Losi 350 lol! I had the same thing happen to a Clockwork modified Nova .28. My switch on my reciever pack went bad and off went my RC8T across my yard. It hit a boulder and flipped upside down. Then it wailed like a banshee till I grabbed it and stopped it with my shoe on the flywheel. It also gave me a "rug burn" from the ballooning tires getting my leg. I was still in my break in period and never got to see what my $450+ engine could do. The high RPM spun a crank bearing and sucked it through the engine. My piston looked like yours!