[Amc-list] Cam bearing oiling

["Bruce Hevner" <scramblr@xxxxxxxxxxx>]

I'll have to dis-agree with whoever it was (can't find the post right
now) who advised oiling the cam bearings on the "clearance" side of the
bearing. This will lead to excessive oil throw off as the bearings wear
and can cause low oil pressure especially at an idle.. The oil hole
should be just AHEAD of the loaded area of the bearing. This helps the
spinning shaft to develop a "wedge" of oil for the shaft to spin on
without allowing an excessive amount of oil to escape.
 I believe they used an SBC as an example. In this example the mfg
recommends the center bearings be installed with the oil hole on the
lower left side of the housing about equal to the bottom of the cylinder
on that side. This puts it just AHEAD of the loaded area of the bearing.
 The 2300 Ford (Pinto) had a big time problem with this especially in
race motors. The way the engine (OHC) was originally designed the cam
oiled from the bottom of the bearing but the bearing was loaded on the
top. We used to cut a groove in the bearing housing so the bearing could
be installed with the oil hole just ahead of the loaded area. Fixed the
problem. Later one of the bearing mfg came out with the groove on the
backside of the bearing. That way you could just install the bearing
with the hole in the new position.
 Pay attention to the worn area of the bearing when the old ones are
removed from the block. You would want your oil hole just AHEAD of this
area so the shaft can develop a wedge of oil at that point. Not always
an easy thing to do depending on the motor but it WILL help low idle oil
pressure and wear problems.
But HEY,,, that's just ME!
Bruce Hevner
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://splatter.wps.com/pipermail/amc-list/attachments/20080316/38fce14a/attachment.htm 
_______________________________________________
Amc-list mailing list
Amc-list@xxxxxxxxxxxx
http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list