BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: Mike Farmer on 04 May, 2021, 21:02

Title: "O" rings
Post by: Mike Farmer on 04 May, 2021, 21:02
 :) :) :) :)

Simple Q.
Is it normal to use a gasket as well as the "O" rings in the oil pipe bloc/engine casing joint.

Two reasons for asking 1. I've recently put one together minus gasket and it's in the frame and running--no leak but??? and another in frame but not running yet. (still time to use a gasket)
2. there doesn't appear to be a gasket in any of the Full Gasket Sets that I have purchased.

What I have been doing is assembling with the "O" rings and a smear of Wellseal and allowing it to almost dry prior to assembly and tightening.

Your thoughts please

Mike 8) 8) 8)

Title: Re: "O" rings
Post by: DAVE BRADY on 05 May, 2021, 07:51
Hi Mike,

I just use the 'O' rings.  If there is a problem the joint can be undone and new rings put in without having to clean the surface of any sealant.

Dave.
Title: Re: "O" rings
Post by: Bess on 05 May, 2021, 09:28
Hi Mike,
             Its not normal to use a gasket or a sealant with an O ring.

Manufacturers will recommend the O ring groove, mating surfaces are clean and the ring is lubricated during assembly. Lubrication is either as recommended by the manufacturer or compatible to the fluids the ring is sealing against.

Best wishes...
Title: Re: "O" rings
Post by: Mike Farmer on 05 May, 2021, 09:36
 :) :) :)

Thanks guys. Thats pretty much what I thought--but--I just obtained a three "spout" block and it had a gasket stuck to it so I wondered.

Heaven only knows how many of these I've done yet these silly Q's keep popping up. Like I say, it's the question that you don't ask that can cause a lotta damage.

Mike 8) 8) 8) 8) 8)
Title: Re: "O" rings
Post by: Mike Farmer on 05 May, 2021, 14:46
 :) :) :) :)

I've just opened a brand new gasket set. I'm not going to tell you what is in it. You'll only need one guess.

Mike 8) 8) 8)
Title: Re: "O" rings
Post by: Ian C on 05 May, 2021, 15:06
I believe the early A65 oil junction was just a gasket, but BSA modified for seals on later models?. I have always used the square section 'O' rings which IMO give a better seal.
Title: Re: "O" rings
Post by: DAVE BRADY on 05 May, 2021, 15:25
Hi Ian,

I believe the square section was the original spec. but they do not always seem to be available.  Where did you get yours?

Dave.
Title: Re: "O" rings
Post by: wardy on 05 May, 2021, 15:28
Just fitted mine without gasket, no issues. Found it helpful to grease the o rings a bit to keep them in situ as there's not a lot of room
Title: Re: "O" rings
Post by: Ian C on 05 May, 2021, 17:33
Quote from: DAVE BRADY on 05 May, 2021, 15:25

I believe the square section was the original spec. but they do not always seem to be available.  Where did you get yours?


I got a few from a fellow branch member a few years back Dave.  He let me know the company he got them from back then, but alas I can't the info!! I'm currently trying to contact him, so will hopefully have an answer soon.
Title: Re: "O" rings
Post by: Bess on 05 May, 2021, 17:37
Hi Mike,
            Looks like you have a gasket set for the 1963-64 bike as the oil header required a gasket. In 1965 the header changed and a X ring was used (BSA called it a joint washer, https://www.ebay.com/itm/NOS-70-8259-68-0598-Oil-Block-O-Ring-Seal-BSA-B25-B44-B50-TR25-68-0598-/332079417426), in 1966 and 1968 other changes and O rings were used for all years from 1966.

People started and are still changing the 63-64 oil header for the better sealing O or X ring option. The issue is that the 1965 X ring and 1966-67 O ring oil headers are different parts, so I guess, if it is unknown which header you have, you wont know which seal to use.

Using the 1968 onwards 3 pipe header is the best option as you know O rings were specified. Also the header is designed to give more oil flow to the head and was a BSA recommended upgrade.

Best wishes...
Title: Re: "O" rings
Post by: Bess on 05 May, 2021, 17:41
Hi,
    If you know the X ring size try ERIKS:

https://shop.eriks.co.uk/en/


Best wishes...
Title: Re: "O" rings
Post by: Mike Farmer on 05 May, 2021, 19:48
 :) :) :)

O Rings on Ebay.

Mike 8) 8) 8) 8)