Subject: Re: those pesky little o rings
Author: Patrick Hayes
Date: Mar 26, 2001, 9:38 PM
Post ID: 1706052548
In a message dated 03/26/2001 6:24:43 PM Pacific Standard Time,
haw-@frontiernet.net writes:
<< Now tell me this; why do we want to stop oil blow by with these little
o-rings when we want oil to get up on the rockers anyway?? What does it
matter how the oil gets up there?? I know we want oil into the rockers
themselves but it is pretty much an oil bath up in the heads isn't it?? >>
Remember, in the Guzzi engine cycle, there are periods of time when both
pistons are moving up and other periods when both are moving down. Thus,
there is a substantial change in the ambient air pressure inside the
crankcase chamber during every rotation cycle. If you don't seal well, you
will pump oil out somewhere. The oil is fed to the head through an external
feed pipe to the head and through drilled galleries to the rocker carriers
and shafts. It drips off and drains down through the head and cylinder
through a small hole low in the head. BE CAREFUL when you install the head
gasket. It goes two ways and you can inadvertently plug this drain hole.
You don't wan any oil passing down along the four perimiter cylinder studs
from above or through the 12 and 6 position studs from the case below. This
oil would eventually bleed out through the head gasket or base gasket.
Patrick Hayes
Fremont CA
EV, EV, SPII, V-65-C, Monza, SuperAlce
MGNOC L-403