RE [alfa] O-rings (was: Oil Leaks on Alfa Four)

[Tom Sahines <tsahines@xxxxxxxxxxxxxx>]

John thanks for the history lesson on the orings. I did not know about the 
Delrin rings, interesting.

I would like to add a little to this discussion.

First removal of roll pins should not be attempted. When they no longer 
protrude from the block simply adding another roll pin, pushing the old one 
in further, is the accepted fix.

Bob Wandell at Import Doctors has successfully used a variation of Freds 
fix for years. He uses brake tubing (steel) rather than brass model tubing.

Currently I use a part made by Jon Norman's shop (Alfa Parts in Berkeley). 
This is a small machined brass tube with steps on both sides. One side is 
press fit into the block and the other end fits loose into the head. A 
small shoulder provides the support for the oring. Jon provides 6 orings 
and 6 pins in a kit. I do not use these orings. I have been using Chevy 
283-327 viton valve stem seals for many years with and without inner 
support with good success. These rings are square cross section rather than 
round and are less prone to change their shape (figure 8 or pretzel). The 
material composition stays pliable after years of service.

Tom Sahines ARA Tech Hot Line San Jose California.


Date: Sun, 4 Jan 2004 23:27:40 -0500
From: "John Hertzman" <johnhertzman@domain.elided>
Subject: [alfa] O-rings (was: Oil Leaks on Alfa Four)
In AD9-1056 Russ Neely writes "In days of old, the O rings would not
retain their shape - they would turn to a pretzel shape. Then someone came 
up with the idea of putting roll pins in the passage where the head joins 
the block. Plus a material called Vitron came along. Vitron O rings plus 
the roll pins to keep them round seems to have solved the problem on most 
late model Alfa four cylinders. I am not sure exactly when Alfa started 
putting the roll pins in at the factory. But I am pretty sure all L 
Jetronic spiders had them, so the change may have been about 1982."
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