Topica Loopframe_Guzzi Archive


Subject: RE: Drip, drip, drip.....

Author: Greg Bender

Date: Apr 30, 2005, 4:52 AM

Post ID: 1718790464



Hi Ray,

Not a stupid question at all...I'm trying to figure this out, too :>

The purpose of the breather is to allow excess pressure from the engine
to escape. This excess pressure comes primarly from blow-by past the
rings. So, the air is pushed up into the breather and carries with it a
lot of oil in a mist. The purpose of the one-way valve, I think, is to
open when there is sufficient pressure AND to not allow oil back in the
way it came (although I don't see why that would be important). This
applies to either the flapper valve or the ball valve. The breather box
should not be removed as it also serves as an air-oil separator.
Essentially, the air/oil mist get's pushed up into the breather and then
the oil settles out and is able to return to the crankcase. If the oil
from the mist is not reclaimed, the engine would run itself dry.

All this being said, there are 3 pipes on the loop breathers. One pipe
(which contains the valve) is where all the air/oil mist comes from. One
pipe allows the oil to drain back to the crank case. And one pipe allows
the air to be expelled to the atmosphere.

My problem, if I understand it correctly, is that I'm getting
substantial blow-by at my rings (my opinion now...to be confirmed when I
get my leak-down tester). The breather is able to keep up under most
circumstances, but becomes overwhelmed and can't keep up when I work the
engine really hard. At this point, the crankcase is so pressurized that
it may even be pushing oil up the oil return line (this is my
suspision).

I don't see any reason why a ball-valve can't be substituted for the
spring loaded flapper valve as long as it is installed correctly...as it
has been a mainstay for Guzzi for many years and a common upgrade.

Ray Hale wrote:
 
Greg,
I know what the breather box and flapper valve is but don't know about
the ball valve, except that it's been stated on this list that it's
"later model". So, is there a possibility of simply replacing the
breather box with the ball valve, rather than all the disabling and
rerouting and such? Understand I'm bringing this in with no knowledge of

one of these pieces at all and my suggestion may be incredibly naive, or

stupid even. But I can take it, and had to ask.

And, while we're at it...would an NOS breather box likely have these
problems? Was it a problem from the get-go? I recall problems with this

on my G5. Looks to be the exact same breather, as I remember. Mine never

puked but certainly the tube was real wet all the time.
Ray
pax sine tedio
73 Eldo "19"


Greg Bender wrote:
 
Hi Kim,

I guess I'm not following you here. Are you saying that your ball valve
was somehow faulty and somehow allowed a bunch of your oil to run out
the belch tube onto the pavement? Am I missing something here?

Kim Schick wrote:
 
Ditto.

A dealer suggested that I install the ball unit under the breather (puke
box) which I did.
Whether or not the puke box was "disabled" or not I'm unsure, but I
think it
was.
Didn't take long after noticing the oil light come on (yes, there was a
slight hint of a problem) that I shut it down (after getting to the
other
side of a very busy bridge). After regrinding the crank, installing
oversize
connecting rod bearings and a new puke box (and removing the ball unit)
it
has run without leaking a drop. Very expensive compared to a puke box,
and
quite embarrassing to boot!

Caution advised.

Kim

�A bend in the road is not the end of the road unless you fail to make
the
turn�



Regards,

Greg Bender
1971 Ambassador
2000 Quota
http://www.thisoldtractor.com/gtbender

Florida MGNOC website
http://www.thisoldtractor.com/fl_mgnoc

Minnesota MGNOC website
http://www.thisoldtractor.com/mn_mgnoc

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