Dead on, John. Nearly all model bearings are at least C3 clearance. Some
real hot engines are even looser. Also, be sure that you get ABEC 3 or
better tolerance bearings as ABEC 1 bearings can be far enough out of
tolerance in the outer ring that you may not be able to properly install
them. Both of these ratings go hand in hand.
Desert Sky Model Aviation
ARFs, engines, bearings, etc
> Bearings from the local bearing supply house will often work
> but in some applications they will have shortened life due to
> inadequate internal clearance. For model engines a C3 clearance is
> best. This is looser than the standard clearance that you get if none
> is specified. You may get away with standard fit in some engines but
> with others you won't. Your shop can probably supply in C3 in many
> sizes. A couple cases where I have found where the tighter bearings
> fail quickly are Webra Speed61 and OS1.08.
> I believe the tightness of the fit of the outer race in the
> case and the heat expansion characteristics of the engine are a couple
> things that affect bearing clearance requirements.
> >I rebuild most of the engines in our club and surronding areas and all
> >I ever do is go to the local bearing company with the old bearings and
> >they supply repalcements that are exact. Never had a problem. The only
> >time they could not find the proper bearing is for the rear bearing on
> >a YS. Its a Nachi and is very narrow and even Nachi claimes its built
> >just for YS. If it comes with seals on both sides just use something
> >sharp to gently pierce the one side and pry out the seal. Try it on
> >the old seal to see how easy it is to remove the seals.
> >On Wed, 5 Dec 2001 07:24:00 -0600, "Bill Fulmer"
> >>Sorry... Yer right about an MDS sucking, but it won't be thru the front
> >>bearing... Crankcase pressure is positive at this point.. Worst case
> >>be a "wet nose"...
> >>> Your going to suck some major air. My bro-in-law had a bad bearing on
> >>> MDS and it ran like total ***until he replaced it.
> >>> IronZ
> >>> > **** Post for FREE via your newsreader at post.usenet.com ****
> >>> > I ordered a new bearing kit from Boca Bearings for my ST 90. The
> >>> bearings
> >>> > I recieved are the same physical size, but the seal on the front
> >>> is
> >>> > different. The original bearing had a sealed bearing type seal on
> >>> side
> >>> > and nothing on the other. The replacement bearing I recieved had
> >>> > dust cover type seals ( not really sealed. On the old bearing, I
> >>> not
> >>> > blow air thru the seal, on the new one I can.
> >>> > Will I have a problem with this new bearing and engine performance?
> >>> > anybody had any experience with these bearings and this motor? I
> >>> > the econo-power bearing kit.
> >>> > --
> >>> > Brad Jensen
> >>> > The only reason I am here, is because I am not all there.
> >>> > *** Usenet.com - The #1 Usenet Newsgroup Service on The Planet! ***
> >>> > http://www.FoundCollection.com/
> John Hawkins - From Canada's Atlantic Coast