KB 3.5 bearing problem

[Carl Van Houten]

Michael,
Did you get your problem fixed?

Dennis, That is top secret stuff dude....

 

[Danny King]

Yeah Carl you’ve been wrong all this time and just lucky i guess! Lmao

FFS it is just installing bearings!!!!!!!!!! Not rocket science.
I sure hope the motor never gets water in it as it will ruin the bearings.
there is more then one way to do things. Or Atleast until the Internet was born.

 

[Brad Christy]

Denis,

I'm guessing you were removing those bearings for a reason....? I wouldn't worry too much about bearings that were going in the trash, either.

I thought I was clear on it not being about thermal expansion.

The reason we freeze the bearings is to counter the heat in the case. There is enough heat in the case when we install the bearing to transfer enough of it into the bearings to cause burns to your fingers. That's hot enough to distort the retainers. If you start off with frozen bearings, the bearings don't get near hot enough to worry about.

Even if you start the engine up in the pits, immediately after retrieving it, the water in the engine has been there for several minutes. The minimal amount of moisture that might have clung to the bearings after being installed frozen was there for a minute at most. Not to mention that the bearings, at least the ones I've installed, were pre-coated with oil coming out of the packaging.

I'm sorry. It just seems like you're stepping over a dollar to pick up a dime.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[Dennis Somers]

LOL Very inventive spin I must say. Moisture steams off at 212 degrees. I don't know about you, but my fingers will burn if I stick them in boiling water. But if that's hot enough to mess up your composite cages, you better find better brgs. Carry on guys.

 

[Daniel's Racing]

You usually aren't ready to start blowing out new bearings and flooding the new engine with oil before your even done with assembling it but you could.
I use a heat gun and when I see the cases smoking I know they are ready. I do use air to cool the cases soon after pressing in the bearings. It has never affected the retainers.

IF YOU HAVE TO REHEAT THE CASES YOU CAN RUIN THEM. Better set them where you want them properly the first time.

I am thinking your nitro cases aren't as tight as some gas engine cases are. Some will open up and accept the bearings others even fully heated you better be ready to put some force behind the install tool and fast. If you don't go in one swift motion you just lost a bearing. If you cool them at all they will not even go in before they have tightened the bore so tight you can't take it home. I am not saying this because I have not tried freezing/cooling bearings. Forget the water that isn't the issue the issue is locking up the bearing in the bore because the ice cold steel sucked it out of the aluminum on contact.

Cooling the steel bearing robs the heat from the aluminum case and defeats what you heat the cases for in the first place. Room temp draws out the heat too fast. Cooled or frozen forget it. Some will lock up before they are fully in the bore from the rapid cooling of the aluminum shrinking on the bearing.

I have done a few bearings and everyone gets aligned in a assembled case so the faces of the outer races are dead true facing each other squarely to one another. This ensures cool running friction free that is running on every ball in the bearing 360° of rotation.

This was just a few of the bearing tubes/packages I found laying around the bench and in a box where junk ones get thrown.

Done a couple. Lol. Was saving cranks until I had several 5 gallon buckets full. Oh yea we were having some fun.

 

[Brad Christy]

LOL Very inventive spin I must say. Moisture steams off at 212 degrees. I don't know about you, but my fingers will burn if I stick them in boiling water. But if that's hot enough to mess up your composite cages, you better find better brgs. Carry on guys.

Denis,

Correct. Water steams off at 212. And what temp are you heating your case to? Exactly.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[Michael Villeneuve]

Hey guys,

Thank you so much for all the info.
I managed to get all the bearing in and seated properly. I did not have to heat uo the case at all, the bearing dropped right in. As far as problem wise, the PTO was giving me issue, couldnt get the bearing seated all the way without either a hammer or a press. So I decided to put it on Lathe at work and pass a quick 4000 grit sand paper and it did the trick, engine is running perfectly

Now I'm having an issue with my other engine, very poor idle, sometimes it'll stall if i remove the glow igniter, sometimes it will start reving super high if i get it started, fuel comes out of the carb and the pipe.
What could be my issue? I was told it might be taking air in from somewhere.

Thanks alot for the help

Mike