ENGINE CONTROLS

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.

Ill.no.	Partno.	Part	Quantity required	Info	Price
1	AHH5300	PEDAL ACEL RHD MGA	1	RHD	CHF 91.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
2	AHH5301	BUSH PB ACCELERATOR PEDAL	1		CHF 6.15

Ill.no.	Partno.	Part	Quantity required	Info	Price
3	AHH5306	FULCRUM PIN	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
4	GHF201	NUT 5/16 UNF	1		CHF 0.35

Ill.no.	Partno.	Part	Quantity required	Info	Price
5	GHF332	WASHER SPRING 5/16	1		CHF 0.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
6	AHH5302	BRACKET-ACEL.RHD MGA	1		CHF 73.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
7	SH604051	SCREW 1/4" UNF X 5/8"	4		CHF 0.95

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
13	SH604051	SCREW 1/4" UNF X 5/8"	2		CHF 0.95

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
17	SH604051	SCREW 1/4" UNF X 5/8"	3		CHF 0.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
18	GHF300	WASHER 1/4 X 1/2 OD	3		CHF 0.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
19	GHF331	WASHER SPRING 1/4	3		CHF 0.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
20	GPR105A	PEDAL RUBBER-ACCELR	1		CHF 6.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
21	AHH5303	DISTANCE TUBE	2		CHF 10.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
22	AHH5304	PEDAL STOP	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
23	SE604121	SCREW, 1/4" UNF X 1.1/2", PAN HEAD	2		CHF 3.00

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

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
28	AHH5380	ADJUSTABLE STOP	1		CHF 27.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
29	SH604051	SCREW 1/4" UNF X 5/8"	2		CHF 0.95

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
31	AHH5830	CABLE ACCELERATOR	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
32	ACA5289	CABLE TRUNNION MGA	1		CHF 15.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
33	AHH5308	PEDESTAL ACCELERATOR CABLE	1		CHF 9.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
34	PMZ308	SCREW, 3/16" UNF X 1/2", PAN HEAD	2		CHF 0.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
35	GHF206	NUT 10.32UNF(5/16AF)	2		CHF 0.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
36	WL700101	WASHER SPRING 3/16	2		CHF 0.15

Ill.no.	Partno.	Part	Quantity required	Info	Price
37	ACC5062	LEVER PIN	1		CHF 6.25

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
40	12A4	TAG, RETURN SPRING ON LEVER	1		CHF 4.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
41	AHH5621	SPRING RETURN MGA	1		CHF 17.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
42	AHH5829	BRACKET	1		CHF 37.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
45	ACH5112	TRUNNION MGA	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
46	GHF206	NUT 10.32UNF(5/16AF)	1		CHF 0.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
47	WL700101	WASHER SPRING 3/16	1		CHF 0.15

Ill.no.	Partno.	Part	Quantity required	Info	Price
48	ACC5062	LEVER PIN	1		CHF 6.25

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
51	AHH5623	ANCHOR BRACKET	1		CHF 31.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
52	AHH5624	SPRING PEDAL MGA	1		CHF 13.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
53	AHH5827	BRACKET	1		CHF 34.00

Ill.no.	Partno.	Part	Quantity required	Info	Price
54	AHH5828	BRACKET	1		CHF 34.00

Ill.no.	Partno.	Part	Quantity required	Info	Price
55	AHH5327	STARTER CABLE RHD	1	RHD models	CHF 44.20
55	AHH5330	STARTER CABLE	1	LHD models	CHF 44.00

Ill.no.	Partno.	Part	Quantity required	Info	Price
57	RFR103	GROMMET, RUBBER, 3/16" ID	1		CHF 7.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
58	3H950	CABLE COUPLING TO STARTER SWITCH	1		CHF 27.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
59	BHA4084	CABLE CHOKE	1	RHD models	CHF 58.30
59	BHA4085	CHOKE CABLE ASSY NCA	1	LHD models	availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
61	PCR311	P CLIP, 3/16" CABLE DIAMETER X 11/32"	1		CHF 7.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
62	RFR103	GROMMET, RUBBER, 3/16" ID	1		CHF 7.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
1	AHH5300	PEDAL ACEL RHD MGA	1	RHD	CHF 91.25
2	AHH5301	BUSH PB ACCELERATOR PEDAL	1		CHF 6.15
3	AHH5306	FULCRUM PIN	1		availability request (add quantity to basket, offer follows)
4	GHF201	NUT 5/16 UNF	1		CHF 0.35
5	GHF332	WASHER SPRING 5/16	1		CHF 0.25
6	AHH5302	BRACKET-ACEL.RHD MGA	1		CHF 73.95
7	SH604051	SCREW 1/4" UNF X 5/8"	4		CHF 0.95
8	GHF300	WASHER 1/4 X 1/2 OD	4		CHF 0.45
9	GHF331	WASHER SPRING 1/4	4		CHF 0.55
13	SH604051	SCREW 1/4" UNF X 5/8"	2		CHF 0.95
14	GHF300	WASHER 1/4 X 1/2 OD	2		CHF 0.45
15	GHF331	WASHER SPRING 1/4	2		CHF 0.55
17	SH604051	SCREW 1/4" UNF X 5/8"	3		CHF 0.95
18	GHF300	WASHER 1/4 X 1/2 OD	3		CHF 0.45
19	GHF331	WASHER SPRING 1/4	3		CHF 0.55
20	GPR105A	PEDAL RUBBER-ACCELR	1		CHF 6.95
21	AHH5303	DISTANCE TUBE	2		CHF 10.80
22	AHH5304	PEDAL STOP	1		availability request (add quantity to basket, offer follows)
23	SE604121	SCREW, 1/4" UNF X 1.1/2", PAN HEAD	2		CHF 3.00
24	GHF200	NUT 1/4 UNF	2		CHF 0.60
25	GHF331	WASHER SPRING 1/4	2		CHF 0.55
26	GHF300	WASHER 1/4 X 1/2 OD	2		CHF 0.45
28	AHH5380	ADJUSTABLE STOP	1		CHF 27.90
29	SH604051	SCREW 1/4" UNF X 5/8"	2		CHF 0.95
30	GHF331	WASHER SPRING 1/4	2		CHF 0.55
31	AHH5830	CABLE ACCELERATOR	1		availability request (add quantity to basket, offer follows)
32	ACA5289	CABLE TRUNNION MGA	1		CHF 15.70
33	AHH5308	PEDESTAL ACCELERATOR CABLE	1		CHF 9.20
34	PMZ308	SCREW, 3/16" UNF X 1/2", PAN HEAD	2		CHF 0.90
35	GHF206	NUT 10.32UNF(5/16AF)	2		CHF 0.90
36	WL700101	WASHER SPRING 3/16	2		CHF 0.15
37	ACC5062	LEVER PIN	1		CHF 6.25
38	GHF200	NUT 1/4 UNF	1		CHF 0.60
40	12A4	TAG, RETURN SPRING ON LEVER	1		CHF 4.75
41	AHH5621	SPRING RETURN MGA	1		CHF 17.10
42	AHH5829	BRACKET	1		CHF 37.05
45	ACH5112	TRUNNION MGA	1		availability request (add quantity to basket, offer follows)
46	GHF206	NUT 10.32UNF(5/16AF)	1		CHF 0.90
47	WL700101	WASHER SPRING 3/16	1		CHF 0.15
48	ACC5062	LEVER PIN	1		CHF 6.25
49	GHF200	NUT 1/4 UNF	1		CHF 0.60
50	GHF300	WASHER 1/4 X 1/2 OD	1		CHF 0.45
51	AHH5623	ANCHOR BRACKET	1		CHF 31.80
52	AHH5624	SPRING PEDAL MGA	1		CHF 13.75
53	AHH5827	BRACKET	1		CHF 34.00
54	AHH5828	BRACKET	1		CHF 34.00
55	AHH5327	STARTER CABLE RHD	1	RHD models	CHF 44.20
55	AHH5330	STARTER CABLE	1	LHD models	CHF 44.00
57	RFR103	GROMMET, RUBBER, 3/16" ID	1		CHF 7.30
58	3H950	CABLE COUPLING TO STARTER SWITCH	1		CHF 27.10
59	BHA4084	CABLE CHOKE	1	RHD models	CHF 58.30
59	BHA4085	CHOKE CABLE ASSY NCA	1	LHD models	availability request (add quantity to basket, offer follows)
61	PCR311	P CLIP, 3/16" CABLE DIAMETER X 11/32"	1		CHF 7.40
62	RFR103	GROMMET, RUBBER, 3/16" ID	1		CHF 7.30