Transplant

[Gary Derian]

Roller bearings are good where it is difficult to oil but they do not have
less friction, once they are moving, than plain journal bearings.  In fact,
many times plowing a roller through oil has more friction than a plain
journal.

Gary Derian <gderian at oh.verio.com>


> COOL DEAL!
>
> Thanks for sharing that info, haven't ever heard/read about stock roller
> bearing apps!
>
> Only Hig Dollar Race setups!!
>
> Good to know!
>
> LATER!
>
> Todd....!!
>
> ----------
>
> James Montebello wrote:
> >
> > > What engines used roller bearings?  What applications?
> > > Shannen
> >
> > A great many engines use roller bearings.  The bottom ends
> > of most two-stroke engines are all roller bearings.
> >
> > A good many four-stroke motorcycle engines have also been made
> > using rolling-element bottom ends.  Harleys use them, most
> > four-stroke singles, and quite a few large displacement fours
> > made by Suzuki and Kawasaki used rollers.  Even on engines
> > with plain main and big end bearings, rollers are typically
> > used at the ends of the crankshaft, and in the gearboxes.
> >
> > Porsche made a few racing engines that used roller bearing
> > bottom ends in the '50s, and '60s.
> >
> > In all cases, the crankshafts are multiple pieces pressed
> > together around the bearings and one-piece rods.  For very
> > high-stress operation, these bits would be welded together.
> > If the crank needed to be rebuilt, the weld was ground off,
> > and the parts pressed apart.
> >
> > Most of these engines are not low power applications, either.
> > The two-stroke GP machines made today produce in excess of
> > 400hp/liter unsupercharged.  The big roller bearing Suzuki
> > and Kawasaki engines are very popular in drag-bike applications.
> >
> > james montebello