FRONT 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
	BTB134E	MGA TWINCAM & DELUXE	1		availability request
	BTB135E	MGA TWINCAM & DELUXE CALIPER	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
2	ATB4244	BRAKE DISC FRONT	2		CHF 92.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
3	ATB4247	DISC BOLT	8		CHF 12.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
4	GHF334	WASHER SPRING 7/16	8		CHF 1.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
5	ATB4256	HOSE BRACKET RH	1		availability request
5	ATB4257	HOSE BRACKET LH	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
6	GHF201	NUT 5/16 UNF	4		CHF 0.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
7	GHF332	WASHER SPRING 5/16	4		CHF 1.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
8	8777	WHEEL CYLINDER 2-1/8 FRONT AFTERMARKET	4		CHF 213.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
20	7H8206	BOLT CALIPER TWINCAM	16		CHF 6.00

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
23	7H8202	SUPPORT PLATE	4		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
24	7H8203	KEEP PLATE MGA TC	2		CHF 26.90

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

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
28	006911	BRAKE BLEED NIPPLE	2		CHF 21.00

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
31	ATB4255	BOLT FRONT CALIPER	4		CHF 41.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
32	GHF335	WASHER SPRING 1/2	4		CHF 1.05

Ill.no.	Partno.	Part	Quantity required	Price
33	ATB4251	SHIM 0.003"	a/r	availability request
33	ATB4252	SHIM, 0.005"	a/r	availability request
33	ATB4253	SHIM 0.020	a/r	CHF 2.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
34	8G8194	SEALS CALIPER FRONT	1	axle set	CHF 39.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
	BTB134E	MGA TWINCAM & DELUXE	1		availability request
	BTB135E	MGA TWINCAM & DELUXE CALIPER	1		availability request
2	ATB4244	BRAKE DISC FRONT	2		CHF 92.95
3	ATB4247	DISC BOLT	8		CHF 12.75
4	GHF334	WASHER SPRING 7/16	8		CHF 1.65
5	ATB4256	HOSE BRACKET RH	1		availability request
5	ATB4257	HOSE BRACKET LH	1		availability request
6	GHF201	NUT 5/16 UNF	4		CHF 0.75
7	GHF332	WASHER SPRING 5/16	4		CHF 1.10
8	8777	WHEEL CYLINDER 2-1/8 FRONT AFTERMARKET	4		CHF 213.40
20	7H8206	BOLT CALIPER TWINCAM	16		CHF 6.00
21	GHF321	WASHER STAR INT 1/4	16		CHF 0.45
22	GBP254	BRAKE PADS DUNLOP	1		CHF 64.80
23	7H8202	SUPPORT PLATE	4		availability request
24	7H8203	KEEP PLATE MGA TC	2		CHF 26.90
25	SH604071	SCREW 1/4" UNF X 7/8"	2		CHF 2.05
26	GHF200	NUT 1/4 UNF	2		CHF 0.60
27	GHF321	WASHER STAR INT 1/4	2		CHF 0.45
28	006911	BRAKE BLEED NIPPLE	2		CHF 21.00
29	BLS106	BALLBEARING 3/16 DIA	2		CHF 0.90
30	ACH5305	BRAKE PIPE FRONT WHEEL CYLINDER	1		CHF 30.80
31	ATB4255	BOLT FRONT CALIPER	4		CHF 41.80
32	GHF335	WASHER SPRING 1/2	4		CHF 1.05
33	ATB4251	SHIM 0.003"	a/r		availability request
33	ATB4252	SHIM, 0.005"	a/r		availability request
33	ATB4253	SHIM 0.020	a/r		CHF 2.40
34	8G8194	SEALS CALIPER FRONT	1	axle set	CHF 39.70