BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: Taffyboy on 23 Oct, 2020, 20:59

Title: a65 cyl. head outer nuts
Post by: Taffyboy on 23 Oct, 2020, 20:59
Is there a tool out there to gain access to the head outer nuts on an a65 when torquing? Cant seem to find nowt. I recall a tool to adjust ford ohc Pinto engine tappets, which from memory, appear the right shape ie 90 degree bend at both ends. 3/8" drive one end, but cant remember the A/f size on the spanner end.  :-\
Title: Re: a65 cyl. head outer nuts
Post by: Nanonevol on 23 Oct, 2020, 22:51
I use a 13 mm crowfoot that fits a 3/8" drive.
It's close enough in size to fit.
(https://i.imgur.com/doNX8HXl.jpg)
Title: Re: a65 cyl. head outer nuts
Post by: chaz on 24 Oct, 2020, 07:28
when I first started working on BSA's there was a picture of a box spanner and a dimension to the centre of the 1/2 drive . this was dimensioned to allow leverage calculation for torquing.
nowadays having used spanners for 40 years, if needed I torque accessable nuts/bolts and get a feel for the rest using a spanner,
Title: Re: a65 cyl. head outer nuts
Post by: DAVE BRADY on 24 Oct, 2020, 09:00
Hi,

There is a thread about this so a search of this forum may help.  What I do is find a ring spanner that fits well rather than an open ended one, and has a 1/2" on the other end.  Put the spanner on the nut and set the torque wrench in the other end but set at 90º to the spanner.  The 90º is important as this means that the torque on the nut is correct. Pull on the torque wrench as normal.  At the required torque an ill fitting spanner will damage the nuts.

There are plenty of 'crows foot' adapters available but they all seem to be open ended and it is quite tight getting the spanner on properly hence use a ring spanner.  Even then it may be necessary to grind it down a bit to get it on properly.

Dave.
Title: Re: a65 cyl. head outer nuts
Post by: JulianS on 24 Oct, 2020, 10:03
This from the BSA service sheets.
Title: Re: a65 cyl. head outer nuts
Post by: Taffyboy on 24 Oct, 2020, 11:36
Just find it unbelievable that bsa themselves, did'nt have a have a tool to buy of the shelf for this. After all, a vital part of any re build. Anyroad, thanks to all for the replies chaps.
Title: Re: a65 cyl. head outer nuts
Post by: Mike Farmer on 24 Oct, 2020, 12:40
 :) :) :)

Hi

I think that formula should read  12" +  3"  =  15.

Mike 8) 8) 8) 8)
Title: Re: a65 cyl. head outer nuts
Post by: chaz on 24 Oct, 2020, 13:26
Julian
thats the one I saw years ago, thanks
Title: Re: a65 cyl. head outer nuts
Post by: Nanonevol on 24 Oct, 2020, 18:40
Sorry that should be a 15 mm crows foot above.  Very close to the 5/16 Whitworth nut on the BSA head.
Title: Re: a65 cyl. head outer nuts
Post by: Greenfield on 27 Oct, 2020, 19:38
Using Dave's system its very important that the spanner and torque wrench are fixed at 90' and that the pull on the torque wrench is at 90'. If you pull more in the direction of the rotating head nut which is more natural, it gets a lot more complicated with the length of the spanner now having an effect, and you will probably apply more pressure and thus produce a reduced tightness.