BSA Owners' Club Forum

The BSA Workshop => Pre War => Topic started by: Tony B on 25 April, 2017, 18:34:33

Title: Petrol tap for 1936 Blue Star.
Post by: Tony B on 25 April, 2017, 18:34:33
As it says in the title, I am looking to replace the petrol tap on my 1936 Blue Star 350.  There are so many on line and I'm not sure of the thread diameters.  The top one is bigger than the bottom one.  It's a Ewart with a patent number 342560 stamped in.
Any suggestions gratefully received, just need a tap to get the beast on the road.
Regards Tony Booth, Padworth, West Berks.
Title: Re: Petrol tap for 1936 Blue Star.
Post by: JulianS on 25 April, 2017, 19:38:54
The threads will be BSP (British Standard Pipe).

1/4 BSP is a common one for pipe union - od 0.518 inch x 19tpi.

Some tanks take 3/8 BSP x 19tpi. OD 0.656 inch.

Also seen 1/8 BSP x 28 tpi. OD 0.383 inch.
Title: Re: Petrol tap for 1936 Blue Star.
Post by: Tony B on 25 April, 2017, 19:52:11
Crikey, and I was hoping it would be a simple - 'this is the one'.
Not to worry, I spotted a bigup for c and d autos in another post so I'll see if they will do a repair or cork replacement for me.

Thanks for the fast reply Julian.
I guess the professional way would be to buy some dividers and measure it accurately, holding a builders tape against it doesn't do my knackered eyesight any good!
Title: Re: Petrol tap for 1936 Blue Star.
Post by: JulianS on 25 April, 2017, 20:05:32
If its roughly 1/2 inch its 1/4 bsp.

If its roughly 5/8 inch its 3/8 bsp.
Title: Re: Petrol tap for 1936 Blue Star.
Post by: Tony B on 25 April, 2017, 20:16:33
Thanks Julian, that suits my simple mind to a tee.