PEDAL BOX & BRAKE MASTER CYLINDER

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	AHH5693	BRAKE PEDAL ASSY	1	RHD	availability request
NI	AHH5100	PEDAL RUBBER MGA&B	1		CHF 2.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
2	AAA4129	BUSH PB BRAKE/CLUTCH	1		CHF 12.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
4	AHH7201	SPACER TUBE-PEDAL	2		CHF 7.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
5	AHH5728	TWIN CAM PEDALSPACER	1		CHF 9.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
6	BH606281	BOLT 3/8UNFX3 1/2	1		CHF 4.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
7	GHF202	NUT PLAIN 3/8 UNF	1		CHF 0.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
8	GHF333	WASHER SPRING 3/8	1		CHF 0.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
9	AHH5692	DISTANCE TUBE	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
10	AHH5762	TUBE ROD	1		availability request

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
12	GHF331	WASHER SPRING 1/4	2		CHF 0.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
13	CLZ515	CLEVIS PIN 5/16" x 1"	1		CHF 3.85

Ill.no.	Partno.	Part	Quantity required	Info	Price
14	GHF301	WASHER 5/16 X 5/8 M8	1		CHF 0.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
15	AAA1628	SPRING RETURN PEDAL	1		CHF 3.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
16	AHH5689	DRAUGHT EXCLUDER	1		CHF 50.50

Ill.no.	Partno.	Part	Quantity required	Info	Price
17	AHH5688	RETAINING PLATE	1		CHF 43.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
18	AHH5687	PLATE BASE	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
19	GHF103	SCREW 5/16 UNF X 1IN	2		CHF 2.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
20	GHF332	WASHER SPRING 5/16	2		CHF 1.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
21	GHF120	SCREW 5/16 UNF X 3/4	2		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
22	GHF201	NUT 5/16 UNF	2		CHF 0.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
23	GHF332	WASHER SPRING 5/16	2		CHF 1.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
26	SH605051	SCREW 5/16" UNF X 5/8"	4		CHF 3.10

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
29	GHF120	SCREW 5/16 UNF X 3/4	2		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
30	GHF201	NUT 5/16 UNF	2		CHF 0.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
31	GHF301	WASHER 5/16 X 5/8 M8	2		CHF 0.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
32	GHF332	WASHER SPRING 5/16	2		CHF 1.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
33	GHF120	SCREW 5/16 UNF X 3/4	6		CHF 0.80

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
35	GHF332	WASHER SPRING 5/16	6		CHF 1.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
37	AHH5753	PEDAL BOX BLIND PLATE	1		CHF 34.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
38	AHH5754	SEAL BLANKING PLATE	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
39	GHF103	SCREW 5/16 UNF X 1IN	2		CHF 2.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
40	GHF120	SCREW 5/16 UNF X 3/4	2		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
41	GHF201	NUT 5/16 UNF	2		CHF 0.75

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
50	BHA4071E	M/CYL EXC	1	original reconditioned	availability request
50	BHA4157	BRAKE MASTER CYLINDER 7/8"	1	alternative replacement	CHF 280.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
51	8G8495Z	MASTER CYL REP KIT	1	for original Dunlop cylinder	CHF 21.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
52	NT605041	NUT 5/16 UNF JAM THIN	1		CHF 1.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
53	SH605101	SCREW 5/16" UNF X 1 1/4"	2		CHF 2.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
54	GHF222	NUT 5/16UNF NYLOC	2		CHF 1.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
55	GHF301	WASHER 5/16 X 5/8 M8	2		CHF 0.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
NI	AHH5693	BRAKE PEDAL ASSY	1	RHD	availability request
2	AAA4129	BUSH PB BRAKE/CLUTCH	1		CHF 12.05
NI	AHH5100	PEDAL RUBBER MGA&B	1		CHF 2.90
4	AHH7201	SPACER TUBE-PEDAL	2		CHF 7.95
5	AHH5728	TWIN CAM PEDALSPACER	1		CHF 9.25
6	BH606281	BOLT 3/8UNFX3 1/2	1		CHF 4.10
7	GHF202	NUT PLAIN 3/8 UNF	1		CHF 0.60
8	GHF333	WASHER SPRING 3/8	1		CHF 0.95
9	AHH5692	DISTANCE TUBE	1		availability request
10	AHH5762	TUBE ROD	1		availability request
11	GHF200	NUT 1/4 UNF	2		CHF 0.60
12	GHF331	WASHER SPRING 1/4	2		CHF 0.55
13	CLZ515	CLEVIS PIN 5/16" x 1"	1		CHF 3.85
14	GHF301	WASHER 5/16 X 5/8 M8	1		CHF 0.40
15	AAA1628	SPRING RETURN PEDAL	1		CHF 3.30
16	AHH5689	DRAUGHT EXCLUDER	1		CHF 50.50
17	AHH5688	RETAINING PLATE	1		CHF 43.75
18	AHH5687	PLATE BASE	1		availability request
19	GHF103	SCREW 5/16 UNF X 1IN	2		CHF 2.20
20	GHF332	WASHER SPRING 5/16	2		CHF 1.10
21	GHF120	SCREW 5/16 UNF X 3/4	2		CHF 0.80
22	GHF201	NUT 5/16 UNF	2		CHF 0.75
23	GHF332	WASHER SPRING 5/16	2		CHF 1.10
26	SH605051	SCREW 5/16" UNF X 5/8"	4		CHF 3.10
27	GHF332	WASHER SPRING 5/16	4		CHF 1.10
29	GHF120	SCREW 5/16 UNF X 3/4	2		CHF 0.80
30	GHF201	NUT 5/16 UNF	2		CHF 0.75
31	GHF301	WASHER 5/16 X 5/8 M8	2		CHF 0.40
32	GHF332	WASHER SPRING 5/16	2		CHF 1.10
33	GHF120	SCREW 5/16 UNF X 3/4	6		CHF 0.80
34	GHF201	NUT 5/16 UNF	6		CHF 0.75
35	GHF332	WASHER SPRING 5/16	6		CHF 1.10
37	AHH5753	PEDAL BOX BLIND PLATE	1		CHF 34.05
38	AHH5754	SEAL BLANKING PLATE	1		availability request
39	GHF103	SCREW 5/16 UNF X 1IN	2		CHF 2.20
40	GHF120	SCREW 5/16 UNF X 3/4	2		CHF 0.80
41	GHF201	NUT 5/16 UNF	2		CHF 0.75
42	GHF332	WASHER SPRING 5/16	4		CHF 1.10
50	BHA4071E	M/CYL EXC	1	original reconditioned	availability request
50	BHA4157	BRAKE MASTER CYLINDER 7/8"	1	alternative replacement	CHF 280.25
51	8G8495Z	MASTER CYL REP KIT	1	for original Dunlop cylinder	CHF 21.55
52	NT605041	NUT 5/16 UNF JAM THIN	1		CHF 1.20
53	SH605101	SCREW 5/16" UNF X 1 1/4"	2		CHF 2.25
54	GHF222	NUT 5/16UNF NYLOC	2		CHF 1.95
55	GHF301	WASHER 5/16 X 5/8 M8	2		CHF 0.40