Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 50, 60, 90 & 100 Talk => Topic started by: RayK on September 05, 2018, 08:55:55 AM

Title: BS90 Rotary disc valve oil seal
Post by: RayK on September 05, 2018, 08:55:55 AM

Help please. Does anyone know if the 47-25-8 rotary disc valve oil seal for 90/100 is double sided or single sided. The 175 47-28-8 oil seal is double sided.
Thanks
Ray

Title: Re: BS90 Rotary disc valve oil seal
Post by: Trev W on September 06, 2018, 01:09:35 AM

Hi Ray , I have had a look at a 90 oil injected engine I have apart & it has a double sided seal( spring both sides )  fitted to it .
 Cheers Trev

Title: Re: BS90 Rotary disc valve oil seal
Post by: RayK on September 06, 2018, 01:33:57 AM

Thanks Trev. As I thought, had some doubts as I didn't have one in my set of seals. The 175 has a double sided seal although larger internal measurement. With your confirmation it makes sense. Now to find a local supplier. Can get single sided only in Canberra @Capital Bearing Supplies. Haven't tried others as yet, any suggestions.
Cheers
Ray

Title: Re: BS90 Rotary disc valve oil seal
Post by: BRT-GTR on September 07, 2018, 07:01:21 AM

          Ray,
                  You may have found this, many seal suppliers offer double sided seals..........great just what we want.  However they turn out to have only one garter spring with the second side being a simple dust seal lip. They are labelled R23 or TC type. Not what we want.  So far, I have been unable to find double garter spring seals in the UK.               Brian.

Title: Re: BS90 Rotary disc valve oil seal
Post by: RayK on September 07, 2018, 08:16:43 AM

Thanks Brian. Looks like the slightly larger 175 seals are available, however the 90 seals may be more difficult to find.
Cheers Ray

Title: Re: BS90 Rotary disc valve oil seal
Post by: Lambretta on September 13, 2018, 10:04:14 PM

https://www.amazon.com/uxcell-Nitrile-Rubber-Double-Rotary/dp/B0089A9ZEU/ref=sr_1_2?s=industrial&ie=UTF8&qid=1536890539&sr=1-2&keywords=47-25-8

Go to amazon, Ebay etc... and type in 47-25-8 Oil Seal.

Title: Re: BS90 Rotary disc valve oil seal
Post by: BRT-GTR on September 14, 2018, 07:54:23 AM

         Lambretta,
                           The Amazon seal you found is an example of what I was saying above. This seal does not have two garter springs. The second lip (as shown in the ad photo) is simply an unsprung rubber dust lip and would be ideal for external wheel bearing or engine seals where dust/grit needs to be excluded.  They may not provide the two way pressure sealing required on our crankshafts.                                                                                                                     Brian.