REAR BRAKES (TWIN & DE LUXE)

CAR IDENTIFICATION MG A TWIN CAM

The Twin Cam MGA was a significant development for MG. It was in production from September 1958 until June 1960, during which period a total of 2111 cars were produced; they were numbered separately from regular MGA production. Being such an extensive development of the push rod 'B' series unit, the Twin Cam engine has little in common with the former. Another major difference from regular MGA's is of course the Dunlop braking system, endowing the Twin Cam with all-round disc brakes and necessitating a modified chassis plus a host of other detail changes.

MGA Roadster Identification Data

Year	Model	Numbers manufactured
September 1955 to May 1959	MGA 1500cc	10101 to 68,850
September 1958 to June 1960	MGA Twin Cam	501 to 2611
May 1959 to April 1961	MGA 1600cc	68,851 to 100,351
April 1961 to June 1962	MGA 1600cc MkII	100,352 to 109,070

BMC 'B' Series Engine Use ( 1953 to 1981)

Model	cc	Prefix	BHP/RPM	Torque
M.G. MGA	1489	BP15GB,15GB	68/5200	82
M.G. MGA	1489	15GD	72/5500	85
M.G. MGA 1600	1588	16GA	80/5600	87
MGA Twin Cam	1588	BC16GB	108/6700
M.G. MGA 1600 Mk2	1622	16GC	90/5500 97

MGA Twin Cam Chassis Numbers

YD1	RHD	Home Market Tourer
YD2	RHD	Export Market Tourer
YD3	LHD	Export Market Tourer
YM1	RHD	Home Market Coupé
YM2	RHD	Export Market Coupé
YM3	LHD	Export Market Coupé

MGA Serial Numbers

Engine Number

The engine number is stamped on a plate secured to the righthand side of the cylinder block...or it is stamped on a plate secured to the rear of the engine behind the cylinder block. (Twin Cam)

Car Number

The car number is stamped on a plate secured to the top lefthand side of the dash panel

Gearbox Number

The gearbox number is stamped on the top of the gearbox casing adjacent to the dipstick

Body Number

The body number is stamped on a plate secured to the bulkhead between the righthand bonnet hinge and the fuse block.

Rear Axle Number

The rear axle No is stamped on the front of the axle tube on the LH side next to the spring seat.

Identifying the MGA

There are only five variations of the MGA. The 1500cc, 1600cc, MkII, Twin Cam and 1600cc MkII De luxe. The Coupés were a variation of the Roadster and were not differentiated by the factory numbering system as to body style. The Twin Cam, a major undertaking at the time of its introduction, was identified separately while the De luxe, the most elusive of MGA models, was not distinctly identified. There are reliable production figures for all models except the De luxe.

The three major MGA models may be readily identified by their tail-lamp and grille configurations as well as their engine displacement.

A 1500cc will have the familiar single Lucas tail lamp, the flush style grille and no shroud or boot lid emblems. Four-wheel drum brakes were fitted to this model only.

Very early 1500ccs had different style gauge faces, an example of which can be found in the factory service manual and drivers handbook illustrations. The door rails on the first few cars were entirely of wood as were the cockpit rear corners. There are few of these seen today. The 1500's did not have the starter hump on the passenger toe board or the windscreen mounted hood clamp. The turn indicators were switched through a relay.

1600cc is differentiated by the dual rear lamp with separate turn lamps, larger round parking lamps with flat lenses and a '1600cc' marker on the cowl and rear boot lid. Disc brakes on the front greatly improved stopping power. The starter position was moved with the resulting hump on the passenger toe board.

The 1600cc MkII received the closest thing to a face lift an MGA ever got. The famous flat grille was replaced with the 'pre-crushed' version. The MkI Mini rear lamps appeared horizontally below the boot lid and the vinyl covered dash and cowl and 1600cc MkII badges were added. The chrome trim and dash escutcheon from the Coupé finished off the dash. Seat belt anchors were added to the chassis. 1600cc MkII De luxe cars used the Twin Cam chassis with the push rod 1622cc engine. Check all parts carefully, as MGA's have not always enjoyed the respect they do now, and parts have been freely exchanged with little regard for originality. When re-wiring your car, be sure to order the loom that fits your body type, not engine type.

unillustrated articles

Ill.no.	Partno.	Part	Quantity required	Info	Price
NI	7H8258E	REAR RH MGA TWINCAM & DELUXE	1	reconditioned	availability request
NI	7H8259E	REAR LH MGA TWINCAM & DELUXE	1	reconditioned	availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
41	ATB7254	BRAKE DISC REAR	2		CHF 145.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
42	GHF243	NUT 3/8 UNF PHILIDAS	8		CHF 3.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
43	GHF302	WASHER 3/8 X3/4 OD	8		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
44	8816	BRAKE CALIPER PISTON & CYLINDER ASSEMBLY	4		CHF 216.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
50	7H8206	BOLT CALIPER TWINCAM	16		CHF 6.00

Ill.no.	Partno.	Part	Quantity required	Info	Price
51	GHF321	WASHER STAR INT 1/4	16		CHF 0.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
52	GBP254	BRAKE PADS DUNLOP	1		CHF 64.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
53	7H8202	SUPPORT PLATE	4		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
54	7H8203	KEEP PLATE MGA TC	2		CHF 26.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
55	SH604071	SCREW 1/4" UNF X 7/8"	2		CHF 2.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
56	GHF200	NUT 1/4 UNF	2		CHF 0.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
57	GHF321	WASHER STAR INT 1/4	2		CHF 0.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
58	006911	BRAKE BLEED NIPPLE	2		CHF 21.00

Ill.no.	Partno.	Part	Quantity required	Info	Price
59	BLS106	BALLBEARING 3/16 DIA	2		CHF 0.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
60	ACH5305	BRAKE PIPE FRONT WHEEL CYLINDER	1		CHF 30.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
62	ATB7259	LOCK PLATE	2		CHF 13.05

Ill.no.	Partno.	Part	Quantity required	Price
63	ATB7262	SHIM 0.003 NCA	a/r	availability request
63	ATB7263	SHIM 0.005 NCA	a/r	availability request
63	ATB7264	SHIM 0.020 NCA	a/r	availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
65	7H8245	PIVOT-HANDBRAKE PAD	4		CHF 17.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
66	8G8197	HANDBRAKE PADSET	1	axle set	availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
67	7H8250	RIVET, SHORT	2		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
68	7H8251	RIVET, LONG	2		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
69	7H8241	BOLT	2		CHF 15.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
70	7H8241A	SQUARE NUT BRASS	2		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
71	7H8241Z	SPRING NCA	2		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
72	LNZ105	NUT 5/16 UNF AERO	2		CHF 2.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
73	008014	LOCK TAB BRAKE	2		CHF 5.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
74	7H8244	CLEVIS PIN	2		CHF 8.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
75	GHF500	SPLITPIN 1/16 X1.5IN	2		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
76	GHF300	WASHER 1/4 X 1/2 OD	2		CHF 0.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
77	7H8245	PIVOT-HANDBRAKE PAD	4		CHF 17.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
78	SP2555Z	REPAIR KIT, BRAKE CALIPER, REAR	1	axle set	CHF 41.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
79	ATB4247	DISC BOLT	4		CHF 12.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
NI	7H8258E	REAR RH MGA TWINCAM & DELUXE	1	reconditioned	availability request
NI	7H8259E	REAR LH MGA TWINCAM & DELUXE	1	reconditioned	availability request
41	ATB7254	BRAKE DISC REAR	2		CHF 145.20
42	GHF243	NUT 3/8 UNF PHILIDAS	8		CHF 3.80
43	GHF302	WASHER 3/8 X3/4 OD	8		CHF 0.80
44	8816	BRAKE CALIPER PISTON & CYLINDER ASSEMBLY	4		CHF 216.65
50	7H8206	BOLT CALIPER TWINCAM	16		CHF 6.00
51	GHF321	WASHER STAR INT 1/4	16		CHF 0.45
52	GBP254	BRAKE PADS DUNLOP	1		CHF 64.80
53	7H8202	SUPPORT PLATE	4		availability request
54	7H8203	KEEP PLATE MGA TC	2		CHF 26.90
55	SH604071	SCREW 1/4" UNF X 7/8"	2		CHF 2.05
56	GHF200	NUT 1/4 UNF	2		CHF 0.60
57	GHF321	WASHER STAR INT 1/4	2		CHF 0.45
58	006911	BRAKE BLEED NIPPLE	2		CHF 21.00
59	BLS106	BALLBEARING 3/16 DIA	2		CHF 0.90
60	ACH5305	BRAKE PIPE FRONT WHEEL CYLINDER	1		CHF 30.80
62	ATB7259	LOCK PLATE	2		CHF 13.05
63	ATB7262	SHIM 0.003 NCA	a/r		availability request
63	ATB7263	SHIM 0.005 NCA	a/r		availability request
63	ATB7264	SHIM 0.020 NCA	a/r		availability request
65	7H8245	PIVOT-HANDBRAKE PAD	4		CHF 17.95
66	8G8197	HANDBRAKE PADSET	1	axle set	availability request
67	7H8250	RIVET, SHORT	2		availability request
68	7H8251	RIVET, LONG	2		availability request
69	7H8241	BOLT	2		CHF 15.65
70	7H8241A	SQUARE NUT BRASS	2		availability request
71	7H8241Z	SPRING NCA	2		availability request
72	LNZ105	NUT 5/16 UNF AERO	2		CHF 2.25
73	008014	LOCK TAB BRAKE	2		CHF 5.10
74	7H8244	CLEVIS PIN	2		CHF 8.20
75	GHF500	SPLITPIN 1/16 X1.5IN	2		CHF 0.80
76	GHF300	WASHER 1/4 X 1/2 OD	2		CHF 0.45
77	7H8245	PIVOT-HANDBRAKE PAD	4		CHF 17.95
78	SP2555Z	REPAIR KIT, BRAKE CALIPER, REAR	1	axle set	CHF 41.40
79	ATB4247	DISC BOLT	4		CHF 12.75