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The Mazda "O" ring installation does not follow suggested methods fro "O"
ring manufacturers. "O" rings are typically trapped loosely in a groove of
specific dimensions. When the groove is closed the "O" ring must not fill the
groove, but be free to move a bit to establish a seal against pressure, and to
prevent a hydraulic event where the total volume of the groove is less than the
volume of the "O" ring. This can break or fracture the groove material, or force
"O" ring material out of the groove area and create a leak.
A good installation would include rigid groove walls which the Mazda does
not have. High oil pressure pushes the rather limp front cover forward and
allows the "O" ring to escape. I have also seen the "O" ring over fill the outer
edge of the land area and form a loop that slips back over the oil passage to
generate a smaller leak.
As can be seen in the excellent Mazdatrix article, Mazda has been dancing
around this problem from day one. A problem that would not have occurred in the
USA. (In my opinion). How about we don't mill the tube to the same height
as the gasket rails? Leave it .045" taller. More pre load and less machine
time. The gasket takes back .018" of that and nobody is the wiser. Nobody looses
face and the "O" rings stay in place for the most part. The solid Teflon washer
like seal sounds real good also. About .030" thicker than the hole depth. There
you go. No "O" ring to pop out.
Lynn E. Hanover
In a message dated 9/1/2012 7:48:09 P.M. Eastern Daylight Time,
cbarber@texasattorney.net writes:
I have oil pressure again.
Sent from my iPhone 4
I just got this
same msg again with no changes but this time it came from Earnst.
Anybody know why? Virus somewhere??
Bill
B
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Finn Lassen
Sent: Friday, August 31, 2012 10:18
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Pesky front
cover O-ring
He still needs to machine the hole for the o-ring
deeper. Unless the teflon ring will fit inside the hole it will act as a
spacer and somehow allow the o-ring to slide out.
Of course he won't
listen to me. I already posted this earlier.
Finn
On
8/31/2012 6:46 PM, hoursaway1@comcast.net wrote:
Chris I do not know the size
of this o-ring you & others have had a problem with but I
have been servicing automobiles for 30 years, automatic trans
& computer controlled sys. as specialty, we use, in some
places Teflon sealing rings in various sizes ( 1/16" X 3/8" to
1.0" around, 1/8" X similar diam. ) they are somewhat soft yet very
strong, they have some crush capability but I am sure they would not blow
out with a high pressure situation. Take an o-ring to any trans shop &
ask to match it to a Teflon ring. Check with Lynn.
David.
From:
"Chris
Barber" <cbarber@texasattorney.net>
To: "Rotary
motors in aircraft" <flyrotary@lancaironline.net>
Sent: Friday, August 31, 2012 3:56:05
PM
Subject: [FlyRotary]
Pesky front cover O-ring
Just pulled my front cover and low and
behold that damned front cover O-ring was fricken GONE. The retaining ring
was in place but no sign of the o-ring. Is it ok to pretty much glue this
damn thing in some how???? Lynn suggested a metal solution but that is
not in my skill set. I have halamar and used it last time. Yes, I did instal
the ring.
So, since I bought it I will be installing the new oil pump.
Heck, the old one is over 20 years old. If any of y'all has a remedy
for this damned thing slipping out you will have my complete attention.
Oh, I am sending a picture or how I am making the front cover area
easier to get to :-)
Chris
Sent from my iPhone
4
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