CYLINDER HEAD

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
2	6K499	DRAIN PLUG	5		CHF 4.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
3	324-545	WASHER COPPER	1		CHF 2.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
4	AEH390	STUD, CAM BEARING CAP TO HEAD	12		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
5	GHF302	WASHER 3/8 X3/4 OD	12		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
6	GHF333	WASHER SPRING 3/8	12		CHF 0.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
7	GHF202	NUT PLAIN 3/8 UNF	12		CHF 0.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
8	CHS2512	STUD 5/16 UNC/F1-1/2	6		CHF 5.50

Ill.no.	Partno.	Part	Quantity required	Info	Price
9	AEH386	VALVE GUIDE INLET	4		CHF 39.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
10	AEH387	VALVE GUIDE EXHAUST	4		CHF 39.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
15	AEH394	INLET VALVE MGA TC	4		CHF 61.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
16	AEH571	EXHAUST VALVE MGA T/C	4		CHF 68.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
18	AEH668C	TWIN CAM SPRING SET MML 60	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
19	AEH396	THRUST WASHER V/SPRG	8		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
20	AEH564	SPRING CUP	8		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
21	433-040	VALVE COTTER HALF	16		CHF 8.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
22	AEH677	TAPPET BUCKET	8		CHF 113.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
23	AEH400	TAPPET SHIM	a/r		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
24	AEH583	STUD INLET NCA	2		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
25	CHS2613	STUD 3/8 UNC/F 1-5/8	5		CHF 4.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
26	CHS2513	STUD 5/16 UNC/F1-5/8	6		CHF 2.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
27	AEH404	SEAL RUBBER	2		CHF 18.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
28	AEJ3	SCREW	6		CHF 3.85

Ill.no.	Partno.	Part	Quantity required	Info	Price
29	AEH548	GASKET HEAD TWINCAM	1		CHF 103.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
30	AEH549	STUD CYLINDER HEAD	10		CHF 23.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
31	12B2246	WASHER CYLINDER HEAD	10		CHF 5.15

Ill.no.	Partno.	Part	Quantity required	Info	Price
32	AEC139	NUT CYL.HEAD MGC/AH	10		CHF 14.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
33	N5C	SPARK PLUG CHAMPION	4		CHF 14.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
38	AEH415	GASKET CAMCOVER INLT	1		CHF 37.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
39	AEH417	GASKET CAMCOVER EXHAUST	1		CHF 33.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
40	324-546	WASHER COPPER	6		CHF 6.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
41	AEH418	DOME NUT 5/16 UNF	6		CHF 29.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
42	SH505091	SCREW 5/16" UNC X 1 1/8"	4		CHF 3.80
42	BH505121	BOLT 5/16UNCX 1 1/2	2		CHF 3.85

Ill.no.	Partno.	Part	Quantity required	Info	Price
44	GHF301	WASHER 5/16 X 5/8 M8	6		CHF 0.40

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
46	AEH419	FILLER CAP OIL	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
47	AEH420	WASHER SEALING	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
48	AEH570	BRACKET DIPSTICK	1		CHF 37.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
49	8G2262	GASKET SET TOP	1		CHF 126.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
54	2K8168	CORE PLUG NCA	2		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
55	112867	GASKET, CARBURETTORS, 1 3/4"	2		CHF 2.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
56	CHS2512	STUD 5/16 UNC/F1-1/2	8		CHF 5.50

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
58	GHF201	NUT 5/16 UNF	8		CHF 0.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
59	AEH578	GASKET INLET MANIFOLD	1		CHF 17.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
60	GHF202	NUT PLAIN 3/8 UNF	5		CHF 0.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
61	GHF302	WASHER 3/8 X3/4 OD	5		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
62	GHF333	WASHER SPRING 3/8	5		CHF 0.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
63	GHF223	NUT 3/8 UNF NYLOC	2		CHF 0.85

Ill.no.	Partno.	Part	Quantity required	Info	Price
64	GHF302	WASHER 3/8 X3/4 OD	2		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
69	AEH194	EXHAUST MOUNTING STUD MGA/C	6		CHF 8.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
70	GHF333	WASHER SPRING 3/8	6		CHF 0.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
71	GHF262	NUT 3/8 UNF BRASS	6		CHF 3.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
72	AEH574	GASKET EX M/FOLD T/C	1		CHF 13.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
73	AHH8382	EXHAUST FLANGE NUT OE	6		CHF 18.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
74	GHF301	WASHER 5/16 X 5/8 M8	4		CHF 0.40

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
76	AEH603	WASHER	2		CHF 6.50

Ill.no.	Partno.	Part	Quantity required	Info	Price
77	GHF332	WASHER SPRING 5/16	8		CHF 1.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
78	AEH414	CAM COVER INLET	1		availability request

Ill.no.	Partno.	Part	Quantity required	Info	Price
79	AEH416	CAM COVER EXHAUST	1		availability request

Ill.no.	Partno.	Part	Quantity required	Price
2	6K499	DRAIN PLUG	5	CHF 4.95
3	324-545	WASHER COPPER	1	CHF 2.40
4	AEH390	STUD, CAM BEARING CAP TO HEAD	12	availability request
5	GHF302	WASHER 3/8 X3/4 OD	12	CHF 0.80
6	GHF333	WASHER SPRING 3/8	12	CHF 0.95
7	GHF202	NUT PLAIN 3/8 UNF	12	CHF 0.60
8	CHS2512	STUD 5/16 UNC/F1-1/2	6	CHF 5.50
9	AEH386	VALVE GUIDE INLET	4	CHF 39.65
10	AEH387	VALVE GUIDE EXHAUST	4	CHF 39.65
15	AEH394	INLET VALVE MGA TC	4	CHF 61.95
16	AEH571	EXHAUST VALVE MGA T/C	4	CHF 68.25
18	AEH668C	TWIN CAM SPRING SET MML 60	1	availability request
19	AEH396	THRUST WASHER V/SPRG	8	availability request
20	AEH564	SPRING CUP	8	availability request
21	433-040	VALVE COTTER HALF	16	CHF 8.10
22	AEH677	TAPPET BUCKET	8	CHF 113.40
23	AEH400	TAPPET SHIM	a/r	availability request
24	AEH583	STUD INLET NCA	2	availability request
25	CHS2613	STUD 3/8 UNC/F 1-5/8	5	CHF 4.60
26	CHS2513	STUD 5/16 UNC/F1-5/8	6	CHF 2.80
27	AEH404	SEAL RUBBER	2	CHF 18.25
28	AEJ3	SCREW	6	CHF 3.85
29	AEH548	GASKET HEAD TWINCAM	1	CHF 103.90
30	AEH549	STUD CYLINDER HEAD	10	CHF 23.30
31	12B2246	WASHER CYLINDER HEAD	10	CHF 5.15
32	AEC139	NUT CYL.HEAD MGC/AH	10	CHF 14.60
33	N5C	SPARK PLUG CHAMPION	4	CHF 14.80
38	AEH415	GASKET CAMCOVER INLT	1	CHF 37.10
39	AEH417	GASKET CAMCOVER EXHAUST	1	CHF 33.70
40	324-546	WASHER COPPER	6	CHF 6.25
41	AEH418	DOME NUT 5/16 UNF	6	CHF 29.45
42	SH505091	SCREW 5/16" UNC X 1 1/8"	4	CHF 3.80
42	BH505121	BOLT 5/16UNCX 1 1/2	2	CHF 3.85
44	GHF301	WASHER 5/16 X 5/8 M8	6	CHF 0.40
45	GHF332	WASHER SPRING 5/16	6	CHF 1.10
46	AEH419	FILLER CAP OIL	1	availability request
47	AEH420	WASHER SEALING	1	availability request
48	AEH570	BRACKET DIPSTICK	1	CHF 37.30
49	8G2262	GASKET SET TOP	1	CHF 126.40
54	2K8168	CORE PLUG NCA	2	availability request
55	112867	GASKET, CARBURETTORS, 1 3/4"	2	CHF 2.25
56	CHS2512	STUD 5/16 UNC/F1-1/2	8	CHF 5.50
57	GHF301	WASHER 5/16 X 5/8 M8	8	CHF 0.40
58	GHF201	NUT 5/16 UNF	8	CHF 0.75
59	AEH578	GASKET INLET MANIFOLD	1	CHF 17.10
60	GHF202	NUT PLAIN 3/8 UNF	5	CHF 0.60
61	GHF302	WASHER 3/8 X3/4 OD	5	CHF 0.80
62	GHF333	WASHER SPRING 3/8	5	CHF 0.95
63	GHF223	NUT 3/8 UNF NYLOC	2	CHF 0.85
64	GHF302	WASHER 3/8 X3/4 OD	2	CHF 0.80
69	AEH194	EXHAUST MOUNTING STUD MGA/C	6	CHF 8.60
70	GHF333	WASHER SPRING 3/8	6	CHF 0.95
71	GHF262	NUT 3/8 UNF BRASS	6	CHF 3.65
72	AEH574	GASKET EX M/FOLD T/C	1	CHF 13.95
73	AHH8382	EXHAUST FLANGE NUT OE	6	CHF 18.45
74	GHF301	WASHER 5/16 X 5/8 M8	4	CHF 0.40
75	GHF332	WASHER SPRING 5/16	6	CHF 1.10
76	AEH603	WASHER	2	CHF 6.50
77	GHF332	WASHER SPRING 5/16	8	CHF 1.10
78	AEH414	CAM COVER INLET	1	availability request
79	AEH416	CAM COVER EXHAUST	1	availability request