<VV> Viton crank seals

[lonwall@corvairunderground.com]

Thanks Carlton - Bob, we appear to be seeing 2 issues here. My original 
objection to Viton "dynamic" seals had to do with wear resistance over 
time. But for some odd reason there are more and more people who are 
having very early failures as well.

As you know, the second issue could have multiple causes - the actual 
material only being one possibility. I was never told by anyone that 
Viton was a material that would not work at all in this application, 
just that it would not hold up over time. The length of time? Unknown.

I have never seen one of the Viton seals close up, but it is interesting 
that one person mentioned that he replaced his with a non-Viton "double 
seal". As Viton is a more expensive material than others it would seem 
possible that the Vitons are not correct copies of the original design 
(the non-Viton are). If so, then that could cause early failures.

Manufacturing defects are possible as well, but as the Viton seals are 
supposedly made by the same manufacturer as the non-Viton, and I have 
never had ANY problem with them, that seems less likely as well.

Lon
www.corvairunderground.com




On 2/10/2012 8:28 PM, Carlton Smith wrote:
> Hi Bob,
>
>   I  bought my Viton seals from Clarks in the fall of 2010 in a complete
> engine rebuild kit. Complete rebuild the engine over that winter. Both front
> and back seals leaked within a week of driving in March 2011. Replaced them
> with both with conventional rubber seals I bought From Lon. 7000 miles
> driven last summer and no leaks!
>
>