Bearing Shield

[Olly]

I'm having a senior moment. LOL

I'm installing new bearings in a Greenhead 67. Do I leave the shield on the small bearing closest to the flywheel or take it out?

Olly

 

[RodneyPierce]

I always leave the outer bearing seal in place.

 

[Duck899]

Yep, I'm with Rodney, I always leave 'em in place.

 

[Thomas Hulbert]

I too would leave shield on the bearing less chance of pressure leakage. Outer bearings leek to leave the seals on due to the possibility of pressure blowout.

 

[Olly]

Thanks - that's good because I had left it in.

 

[Don Ferrette]

I never leave the shields in as they turn into crap traps.

 

[tnrcboatracer]

Shields do not seal the motor, they have a small gap at the ID. Seals can help, but if you need them, the motor needs to be fixed.

 

[moparbarn]

I never leave the shields in as they turn into crap traps.

then quit running in crap, don :blink: :lol: :lol:

 

[Joe Warren]

I never leave the shields in as they turn into crap traps.

I never leave the shields in as they turn into crap traps.

I agree with Don. It came with them OUT from CMB....... When the engine case is under pressure it needs to be able to pressurize the brg for lubrication. the shield will Never take the place of a Good Crank seal if it is damaged?? B)

 

[JimZaremski]

I'm with Jon in that I don't see any reason to leave them in; shields don't actually seal anything, they just prevent larger pieces of grit from getting in there. actual seals IME add drag and if you need them you've got other problems.

I have a couple of sirens which need shielded bearings because they're out in the open and have no lubrication supply other than the original packing, and seals would inhibit the ability to coast.

 

[Olly]

OK - so 3 for, 3 against, 1 no commitment and one a dig at Don. I'm confused. Not really a senior moment after all. LOL

 

[Ray Sametz]

:lol: One senior to another, pop the flywheel and remove the shield. OMHO, I need a nap.

 

[Duck899]

They are shields and not seals. I've ran without them and with them, never saw any difference. I've been changing bearings in engines since 1976. I just leave them in and change bearings in a CMB 67 every year. I run about 6 races a year of 4 heats each. Sometimes I change them twice a year, depends on how hard I run the engine or if a big contest is coming up and you want top notch performance. Try it either way. Pretty sure they are just dust caps for the most part and to be removed after bearing install.

In my Precision Aero (Nelson) controline engines from Randy Smith the engines come with the shields installed.