<VV> Here we go again...

[corvairs]

         And as long as I'm at it.........I would really like this Viton 
seal issue to get explained again.  There are 2 issues here.

1) A number of years ago the tail end of production of some Felpro and 
Victor crank seals had dimensional issues -NOT material issues - 
dimensional issues. Many of us had trouble with them leaking, especially 
the bell housing seals. This was NEVER because of the materials they 
were made of - it was because they did not fit properly on the crank hub 
- PERIOD. The common fix then was to use a redi-sleeve.

Finally I and another vendor had our own crank seals made to correct 
dimensions. Problem solved! Oh it's never that simple. At the time the 
manufacturer wanted to know if we wanted them in Viton. I said - "What 
for?". Well because my competitor was getting some made that way. 
Whatever. Then I find a ringing endorsement for the Viton seals in his 
catalog from one of my customers. Never mind that my new seals worked 
fine too - the Viton seals don't work properly because they're Viton - 
they work properly because they're dimensionally correct????  Why am I 
the only one who gets this????

See, Viton is a magic word to many Corvair people. For obvious reasons. 
But, like any other material, it has it's uses. Would Corvair owners be 
impressed if I started selling Viton windshield wiper blades or wheel 
bearings with Viton seals? How about Viton seat cushions? After all, if 
it's Viton is has to be better (pay no attention to the man behind the 
cutain!)

2) Ok Lon, big deal. The Viton seals don't cost that much more, so why 
not use them. The reason I haven't sold them is because - According to 
the head engineer at Parker Seal Viton is "not a preferred material for 
dynamic seal locations". Dynamic, as opposed to "static" are seals that 
seal a moving surface, like a rotating shaft. When Viton is used in a 
static position, like a draintube O ring, it works fine. But on a 
rotating shaft it MAY not wear, last or even seal as well as other 
materials.
As for the extra heat resistance that Viton has over those other 
materials - if you need that kind of heat protection at your crank ends 
then you've got SERIOUS heat trouble and will have lost many other 
components in the engine before your Viton crank seals protect you from 
anything.. Remember that Viton is generally only used at the rocker 
studs (on the head near the combustion chambers) and the draintubes 
(ditto). 

The maximun safe oil temp at the crank ends is LESS THAN HALF the temp 
rating for Viton. So where's the fire?

But I seem ready to give up. Like so many issues, common sense and a 
rational approach doesn't seem to factor in. Should I give in and sell 
the Viton seals? Lon

www.corvairunderground.com


B. King wrote -

> I also had the seal issue on another car using the best Clarks viton
>
>> seal. I'm installing a Speedi Sleeve.
>
>