<VV> viton pump cups/crank seals

[J R Read]

Thanks Lon,

So, in summary - is it fair to say...   Not a concern or only insignificant 
concern with pump cups, but a definite concern with crankshaft seals?

Later, JR


----- Original Message ----- 
From: <corvairs at pacifier.com>
To: "J R Read" <hmlinc at sbcglobal.net>
Cc: "Joel McGregor" <joelsplace at earthling.net>; <virtualvairs at corvair.org>
Sent: Tuesday, September 06, 2011 4:59 PM
Subject: Re: <VV> viton pump cups/crank seals


> JR - His observations at the least are rational. I have NOT heard any
> advice against using Viton for pump cups but I was warned by head
> engineers at Parker several years back to stay away from Viton in
> "dynamic" (rotating) seals. Whether some of the same problems could come
> up with pump cups so far no one has given an educated opinion.
>
> Lon Wall
> www.corvairunderground.com
>
>
>
>> Lots, but you are now mentioning the main reason for my concerns.  Has
>> there
>> been any adverse reports regarding wear when using the viton crank seals?
>> Anyone?  They've been around for a while now, so I'm wondering if any
>> problems have been noted.
>>
>> Later, JR
>>
>>
>> ----- Original Message -----
>> From: "Joel McGregor" <joelsplace at earthling.net>
>> To: <virtualvairs at corvair.org>
>> Sent: Thursday, September 01, 2011 7:06 PM
>> Subject: Re: <VV> [fastvair] Re: viton pump cups
>>
>>
>>> It seems to me that a crank seal does a lot more moving than anything in
>>> a
>>> carb.  How many inches per hour would 3500RPM convert to on the crank
>>> hub
>>> circumference?
>>> Joel McGregor
>>> ________________________________
>>>
>>>> Hi Dan,
>>>>
>>>> But, it also seems that the typical use of viton is in more or less
>>>> stationary settings like seals, gasket, hose, etc.
>>>>
>>>> Accelerator pump cups are in a moving setting and in contact with the
>>>> metal
>>>> of the carb - sort of a 'moving seal' if you will. Are there any
>>>> studies
>>>> that you might be aware of which would indicate adverse (or
>>>> non-adverse)
>>>> effects on the accelerator pump 'barrel' or to the viton itself in that
>>>> specific (or a similar) setting?
>>>>
>>>> Later, JR
>>>