08. Clutch & Brake Hydraulic System | Turner 950 Part and Assembly Information

Period Girling advertisement mentioning Turner next to all the “big guys”

In 1959 the Turner 950 BMC-A and Coventry Climax got disc brakes as a factory option. This was the recently introduced (second generation) Girling Type 10 disc brake system. Girling (part of the Lucas group) began experimenting with disc brakes on race cars in 1952. An early generation Girling Type A solid caliper 11″ disc brakes had been used on the Triumph TR3 from 1956. Turner (as a small company) was one of the earlier adopters (1959) installing disc brakes on their sports cars. It required the use of special mounting brackets to mount the callipers to otherwise standard front hubs.

Girling Type 10 Callipers (Turner H5 and H5A) and Mounting Brackets (Turner H6) on my Alexander-Turner 950

Complete Girling front brake system on Turner 950

Girling Type 10 Disc Brakes

Applications:

Austin Healey Sprite Factory Conversions (Sebring Sprite) from 1959 onwards
Berkeley Bandit from 1960 onwards
Turner 950 BMC-A (optional) and Coventry Climax from 1959 onwards

Girling part no Description (and Turner reference number)

64032502 Calliper assembly LH (Turner H5)
64032503 Calliper assembly RH (Turner H5A)
64325873 Piston
64325183 Calliper mounting bracket (Turner H6 2x)
64325186 Disc (Turner H11)
64325027 (GDB 509 – DS 5S) Pad
64325418 (GDB524) Pad (alternative)
64325022 Pad Retaining Pin
64325009 Retaining Pin Clip
SP2507 Service kit callipers

Exploded view of Type 12 calliper; Type 10 is similar

Pistons 64325873 tend to corrode after many years of use (moist in brake fluid!) and are hard to find. I had new ones made in Cr Ni steel according above left drawing. Also the pins 64325022 have a hard life and making new ones is not so difficult (see 2nd drawing). These items are both used in Type 10 and Type 12 systems.

Girling Type 12 Disc Brakes

Applications:

Triumph Herald Oct 1961 onwards
Triumph Vitesse “6” 1962 onwards
Turner GT and Coventry Climax 1220 from 1962 onwards

Girling part no Description

64032604 Calliper assembly LH
64032605 Calliper assembly RH
Non-Girling part Disc
64325708 Pad
SP2529 Service kit callipers

Discs dimensions for Turner Sports 950 BMC-A and Coventry Climax from 1960 onwards

Original Girling code was 64325186 (for Turner H11)

Dimensions	Metric	Inch
Outer diameter	Ø 217	8 9/16”
Overall width	23.5	15/16“
Disc thickness	9.6	3/8”
Minimum allowed thickness	8.6
Centre hole diameter	Ø 63.5	2½
Bolt pitch circle	Ø 87.3	3 7/16
Bolt hole (4x)	Ø 9.6	3/8”

These Girling discs are no longer available. Whether Girling also provided the hubs is still point of investigation. The origin (and supplier) of the Turner hub is unclear.

Other potential Turner suppliers had different dimensions: Austin-Healey Sprite has a bolt pitch circle of Ø 81.0. Triumph (Herald, Spitfire) had indeed a value of Ø 86.6 mm, but the disc is otherwise different (overall width and diameter) and cannot be used.

The Ford Escort Mk1 1300 GT disc comes very close with a bolt pitch circle of Ø 86.4 although this is a non-Girling system.

Front Brake Pads for Turner 950 BMC-A and Coventry Climax from 1960 onwards

Original Girling part number 64325418 or GDB524(no longer available). Dimensions: 62 x 43 x 15 mm. Same part number is also used as rear brake pads on Lotus cars:

Elan 1.5 (1962-1965)
Elan 1.6 (1966–1974)
Elan 2+2 1.6 (1967-1971)
Elan 130/4 (1971-1974)
Elan 130/6 (1972-1975)
Elite 1.5 (1958-1964)
Elite Mk II (1961 on)

Corresponding Lotus part numbers:

036J6066 (non-servo version)
036J6064 (servo version)

Other brands that supply this product:

NU-TEXA DP46
EBC DP145 complete axle set
Bendix B300119
Ferodo FER DA3 FF 517

Bendix B300119

Ferodo DA3 FF 517

Modification of Ford Escort Mk1 1300 GT Front Brake Discs

Ford Escort Mk1 GT discs can be made to fit with slight machining. Original Ford part number: (Ford GB) 3026E1123C/68AB1125AA; (Ford D) 1450669. This disc is used on Ford Escort Mk1 1300 GT (from 8/1969 till 11/1974). For dimensions and tolerances see Brembo drawing (below).

Other manufacturers that supply this disc type:

Brembo 08164310
Ferodo DDF 009
EBC D080
SAP motor parts BDC 1018
Autonational BDC 0079

Comparison of dimensions Turner versus Ford disc:

Dimensions	Turner	Ford
Outer diameter	Ø 217	Ø 218.6
Overall width	23.5	23.3
Disc thickness	9.6	9.65
Minimum allowed thickness	8.6	8.6
Centre hole diameter	Ø 63.5	Ø 63.1
Bolt pitch circle	Ø 87.3	Ø 86.4
Bolt hole (4x)	Ø 9.6	Ø 9.9

The Ford Escort Mk1 GT disc has a different pitch circle (about 1 mm smaller) which does not allow a direct exchange. Three possible solutions:

New holes have to be drilled at the correct pitch circle Ø 87.3 mm.
The holes in the Ford disc have to be enlarged from Ø 9.9 to Ø 10.5 mm.
The holes in both hub and disc to be enlarged to Ø 10.0 ^+0.05 mm.

Girling Type 10 on Sprite Factory Conversions (Sebring Sprite)

The Donald Healey Motor Company supplied conversion parts (as per Sebring Sprite) including wire wheels and disc brakes with special Ø 8½” (216 mm) front discs and Girling callipers (1958-1961).