Viton or Silicone rear main seals SBC

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RT Machine
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Viton or Silicone rear main seals SBC

Post by RT Machine » Mon Nov 13, 2017 5:44 am

Is there any real difference in sealing ability and longevity between Viton or Silicone [2 piece] type rear seals in a performance application ?
Viton has a higher heat rating and twice the price, but are they better ?

Sparksalot
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Re: Viton or Silicone rear main seals SBC

Post by Sparksalot » Mon Nov 13, 2017 6:17 am

Yes, Viton is far superior in that application.

engineguyBill
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Re: Viton or Silicone rear main seals SBC

Post by engineguyBill » Mon Nov 13, 2017 12:41 pm

I have always used silicon rear main seals, with excellent results. Available from many sources, but all are probably manufactured by Fel-Pro.
Bill

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A_VAS
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Re: Viton or Silicone rear main seals SBC

Post by A_VAS » Wed Nov 15, 2017 5:38 pm

Viton will not swell or change properties much in the presence of hot engine oils
viton has better low temperature performance, down to like -40*C.

it is far superior to silicone in those 2 areas.
raw material is about 15x the price of a regular VMQ silicone
too lazy to make power w/o boost

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