Seagull Threads (Nuts and Bolts)

[Nudge]

This may be some help to others, I am slowly adding more as I need or work them out.
If I have any incorrect or you have more to add please let me know and I can fix it.

Seagull Threads

Flywheel nut 7/16 x 18 BSF
villiers coil base lug studs 2 BA. Brass nuts
Villiers carb retaining clamp 1/4 x 28 unf
Villiers carb inlet 1 3/16-28 Brass (1 3/16-28 UNS is close and will work)
Fuel tank tap lower thread 7/16 x 19 55°gas thread
Fuel tank tap upper thread 1/8 x 27 60° nps parallel pipe thread (can someone please check)
Fuel cap 1-1/4 7 TPI 55deg
Amal float bowl 1/4 BSP,
Spark plug A6 or D16 M18 x 1.5mm pitch 1” spanner(for the D16)
Gearbox pinch bolt 5/16 BSF
Cylinder head bolts 5/16 BSF
102 Tiller wing nut 3/8 BSF
416 carb cowl drill 30.7mm tap 24 TPI 55° (1 1/4-24 Brass) UNS is close and will work
exhaust tube to the cylinder block is 2 BA.
transom bracket thumb screws are 7/16 BSW.
Early 102 waterpump housing to gearbox fastener 5/16" BSF
Flywheel woodruff key Imperial 5/8'' by 5/32".
securing bolt for a WIPAC/Villiers ignition base to crankcase 5/16" brass (this may be 5/16 Cycle thread (26 tpi, 60 degrees)) Needs to be checked


If bolt is close to 8mm then it will 5/16 BSF
If bolt is close to 6mm then it will 1/4 BSF

TORQUE SETTINGS FOR BRITISH SEAGULLS

5/16" CYLINDER HEAD BOLTS 18FT.LBS

5/16" CYLINDER BASE BOLTS 18FT.LBS

1/4" CYLINDER BASE NUTS 9FT.LBS

1/4" CRANKCASE BOLTS 9FT.LBS

9/16" DOME NUT FOR FLYWHEEL 24FT.LBS

BEVEL PINION DRIVE SLEEVE 20FT.LBS

Distance between bracket and water line:
SJM=355 mm, SJP=410-425 mm, SJPL=555-565 mm, LLS=410-425 mm, LLSL=555-565 mm, TC & THC=410-425 mm, TCL & THCL=555-565 mm.

[Hugz]

Good work!

I've bookmarked this.

[Gannet]

Yes, that is useful.
A couple more:-
!. The screw holding the exhaust tube to the cylinder block is 2 BA.
2 The transom bracket thumb screws are 7/16 BSW.

These two refer to the Forty Series.

A nit- picking comment is that torque values are correctly specified as lbs.ft and not lbs/ft.

Jeremy

[Nudge]

Thanks
I have added the threads to my list (once I have worked out a few more I will update this list).
I have also fixed the lbs/ft to lbs.ft

[Nudge]

This is some usefull info about spanner sizes

http://classicmechanic.blogspot.co.nz/2 ... chart.html

MM, AF, BSW, BSF Spanner Conversion Chart

If your classic was built - or at least designed - before 1960, there is a strong chance it will contain a combination of Imperial AF and Whitworth bolts and fixings. If it's Continental, metric fittings will be the standard.

The following chart allows you to convert easily between all of the major standards - MM, AF, BSW and BSF - making it a lot easier to find a spanner or socket to fit.

Metric bolts, which are measured in MM across flats (edge-to-edge) of the bolt head, are the most common fittings for continental vehicles. In an attempt to standardize certain fittings, some metric sizes which have an Imperial equivalent have been used for major fittings (such as wheel nuts) for many years. After around 1970, wheel nut sizes have virtually been globally standardized at 19mm, an almost exact match for a 3/4in AF socket in Britain. Likewise, earlier vehicles have 18mm wheel nuts, corresponding directly to 3/8in Whitworth (BSW).

The most common Imperial standard in classics built after 1960 is the 'increments of one inch across flats' or 'AF' system. A good quality AF socket set will fit the vast majority of fittings on a British classic car.

The 'Whitworth standards', of which the most common are BSW (British Standard Whitworth) and BSF (British Standard Fine), are a collection of standards based on the Whitworth thread. Devised by Victorian Industrialist Joesph Whitworth in 1841, it became the World's first standard for fittings, hugely benefitting Britain's Industrial Revolution. Whitworth set out the thread angle and pitch of a bolt, which increases in a ratio the larger the bolt becomes. The size of the bolt head also increases proportionally. The 'sizes' of Whitworth spanners refers to the diameter of the threaded stud, and not the bolt head itself: it is not an AF system. For this reason, BSF spanners are one size larger than the equivalent BSW, despite the fact that the bolt head is exactly the same size. The difference in measurement refers to the fact that the threaded section is thicker.
If you own a classic built or designed before 1960, and you are regularly struggling to find a spanner or socket to fit nuts and bolts (particularly on bodywork), it is a wise idea to invest in a set of Whitworth tools.

[Hugz]

Early 102 waterpump housing to gearbox fastener 5/16" BSF
Flywheel woodruff key Imperial 5/8'' by 5/32".

[Nudge]

Cool! I have added them to the list up the top.

[Henk]

Only a country like Britain could develop three different tool size standards, and use them all at the same time, at random...

[Nudge]

What is thread size of the securing bolt for a WIPAC ignition base to crankcase?
Thanks

5/16 brass.

Added to the top list,

Thanks

[headdownarseup]

Another nit picker here!
Wheel nut sizes, although as you say in days gone by a lot of cars had at the time a "standard" size of 19mm, nowadays there's quite a lot of modern cars out there (bmw,audi,mercedes,peugeot,renault,vauxhall/chevrolet/daewoo,suzuki,volkswagen/skoda/seat) and possibly a few others that have a 17mm wheel nut. Off the top of my head i think Ford have stuck with 19mm as a standardised size for a long time now.
Interestingly there is more of a shift towards a wheel bolt rather than a conventional nut as in days of old. Funny how times have changed.

Not that any of this really matters when it comes to seagulls of course.


Jon

[Keith.P]

It's like everything else, why make a stud and a nut, when you can just make a bolt, to save money.
Now most cars are sold without a spare wheel.

A pirate walks into a bar with a steering wheel on his pants, a peg leg and a parrot on his shoulder.

The bartender says, "Hey, you've got a steering wheel on your pants."

The pirate says, "Arrrr, I know. It's driving me nuts."

[AusAnzani]

A pirate walks into a bar with a steering wheel on his pants, a peg leg and a parrot on his shoulder.

The bartender says, "Hey, you've got a steering wheel on your pants."

The pirate says, "Arrrr, I know. It's driving me nuts."

lol

Not quite on topic, but I'm sure there is a link there somewhere.

[dandrews]

Remember, 19 Sept is "international talk like a pirate" day. Arrr.

[Liam2k3]

Right at the top. 7/16 thread on the crank shaft nut. The standard thread for BSF IS 18 tpi. Why does it state 16 tpi. Only noticed because ive just made a new nut and couldnt find 7/16x16 tap

[Nudge]

I will have to have a look into that and make sure it is not a typo.
Thanks for bring it up.