INTERNAL ENGINE

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
NI	8G2257STD	MAIN BEARING SET-STD	1		availability request (add quantity to basket, offer follows)
1	8G2335	MAINS MGA 1622 STD	1	1622cc, alternative	CHF 109.50
1	8G2335/10	MAINS MGA 1622 +10	1	1622cc, alternative	CHF 109.50
1	8G2335/20	MAINS MGA 1622 +20	1	1622cc, alternative	CHF 109.50
1	8G2335/30	MAINS MGA 1622 +30	1	1622cc, alternative	CHF 109.50
1	8G2335/40	MAINS MGA 1622 +40	1	1622cc, alternative	CHF 109.50

Ill.no.	Partno.	Part	Quantity required	Price
2	BHM1294	THRUST SET STD 4PCS	1	CHF 22.05
2	BHM1294/5	THRUST SET+.005 4PCS	1	CHF 22.05
2	BHM1294/10	THRUST SET+.010 4PCS	1	CHF 22.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
3	AEH519	OIL SEAL REAR	1		CHF 98.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
4	1G765	SPIGOT BUSH	1		CHF 6.15

Ill.no.	Partno.	Part	Quantity required	Info	Price
5	1G2874	RING GEAR, 120 TEETH, 10 3/4" ID	1		CHF 38.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
6	AEH541	DOWEL NCA	2		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
7	51K1022	FLYWHEEL BOLT MGA&B >65	6		CHF 18.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
8	6K26	LOCKTAB FLYWHEEL 3BRG B SERIES	3		CHF 7.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
9	FNZ506	NUT 3/8 UNF HT	6		CHF 2.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
10	51K894	STUD - MAIN END MGA	6		CHF 20.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
11	GHF335	WASHER SPRING 1/2	6		CHF 1.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
12	LNZ108	NUT 1/2 UNF AERO	6		CHF 4.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
15	BHM1212	CAM BRG SET B SERIES	1		CHF 26.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
17	12H1638	GASKET MAIN BEARING CAP, CORK	2		CHF 2.85

Ill.no.	Partno.	Part	Quantity required	Price
19	AEH556KSTD	RING SET STANDARD	1	CHF 110.35
19	AEH556K020	RING SET, 0.020"	1	availability request (add quantity to basket, offer follows)
19	AEH556K030	RING SET +0.030"	1	CHF 131.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
20	AEH690STD	PISTON SET STD MGA T/C	1	8.3:1 Comp ratio	CHF 1'025.00
20	AEH690020	PISTON SET +20 MGA T/C	1		CHF 1'025.00
20	AEH690030	PISTON SET +30 MGA T/C	1		CHF 1'025.00
20	AEH690040	PISTON SET +40 MGA T/C	1		CHF 1'025.00
20	AEH690060	PISTON ASSEMBLY SET	1		CHF 1'025.00

Ill.no.	Partno.	Part	Quantity required	Info	Price
21	CCN214	CIRCLIP 1 IN INT BORE	8		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
22	AEH647	CON ROD BOLT	8		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
23	6K881	LOCK TAB BIG END >70	4		CHF 4.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
24	C17164	BUSH SMALL END TR CYL	4		CHF 11.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
25	8G2259STD	CON ROD BEARING SET STD	1	standard size only	availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
30	AEH619	HALF SPEED SHAFT	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
31	AEH608	PLATE LOCATING	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
32	GHF117	SCREW 1/4UNF X 3/4	3		CHF 1.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
33	GHF332	WASHER SPRING 5/16	3		CHF 0.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
34	AEH454	TACHO DRIVE GEAR	1		CHF 206.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
35	WKN304	WOODRUFF KEY CAMSHAFT REAR 1/2 D X3/32	1		CHF 3.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
36	1H605	Clip, end of camshaft	1		CHF 3.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
37	AEH426	GEAR, CRANKSHAFT	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
38	2H326	WOODRUFF KEY CRANKSHAFT	1		CHF 5.50

Ill.no.	Partno.	Part	Quantity required	Info	Price
39	AEH427	OIL THROWER	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
40	AEH449	GEAR, HALF SPEED SHAFT	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
41	WKN505	WOODRUFF KEY CAMSHAFT 5/8 D X5/32	1		CHF 4.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
42	WKN304	WOODRUFF KEY CAMSHAFT REAR 1/2 D X3/32	1		CHF 3.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
43	AEH451	BOLT	1		CHF 19.35

Ill.no.	Partno.	Part	Quantity required	Info	Price
44	AEH452	GEAR WASHER	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
45	AEH453	WASHER NCA	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
50	8G2261	CAMSHAFT BEARING SET #	1	12 pieces	CHF 277.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
51	AEH412	PIVOT STUD	2		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
52	CCN108	CIRCLIP	2		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
53	AEH413	BOLT SPROCKET	4		CHF 17.60

Ill.no.	Partno.	Part	Quantity required	Info	Price
54	SH605051	SCREW 5/16" UNF X 5/8"	2		CHF 3.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
55	AEH340	CASTELLATED NUT	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
56	AEH341	WASHER, LOCK TAB	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
57	WKN505	WOODRUFF KEY CAMSHAFT 5/8 D X5/32	1		CHF 4.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
58	AEH446	SHIM 0.002 NCA	a/r		availability request (add quantity to basket, offer follows)
58	AEH447	SHIM 0.003 NCA	a/r		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
64	AEH372	TIMING CHAIN MGA TC	1		CHF 45.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
65	AEH332	DAMPER BRACKET	2		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
66	AEH334	DAMPER CAM GEAR	2		CHF 55.00

Ill.no.	Partno.	Part	Quantity required	Info	Price
67	CRS207	RIVET	4		availability request (add quantity to basket, offer follows)

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
69	GHF332	WASHER SPRING 5/16	4		CHF 0.25

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
75	CCN118	CIRCLIP	1		CHF 2.85

Ill.no.	Partno.	Part	Quantity required	Info	Price
76	GHF304	WASHER 1/2 X 15/16	1		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
77	AEH343	WASHER, LOCK TAB	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
78	AEH623	NUT	1		CHF 4.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
79	AEH362	ADJUSTER SCREW	1		CHF 6.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
80	GHF208	NUT 5/16 UNC	1		CHF 0.80

Ill.no.	Partno.	Part	Quantity required	Info	Price
81	AEH561	SPRING	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
82	AEH370	BOLT	2		availability request (add quantity to basket, offer follows)

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
84	AEH371	WASHER, LOCK TAB	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
85	6K649	OLIVE VACUUM PIPE	2		CHF 1.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
86	2A459	NUT MALE, CARBURETTOR END	2		CHF 13.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
87	6K4973	SEALING WASHER	1		availability request (add quantity to basket, offer follows)

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
90	AEH359	BANJO BOLT	1		CHF 30.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
91	AEC346	FLAT WASHER 3/8 ID	2		CHF 5.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
92	GHF101	SCREW 1/4 UNF X 1IN	1		CHF 0.80

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

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
95	AEH360	BANJO BOLT	1		CHF 25.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
96	AEH520	WASHER, SEALING	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
97	AEH375	STUD	4		availability request (add quantity to basket, offer follows)

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
NI	8G2257STD	MAIN BEARING SET-STD	1		availability request (add quantity to basket, offer follows)
1	8G2335	MAINS MGA 1622 STD	1	1622cc, alternative	CHF 109.50
1	8G2335/10	MAINS MGA 1622 +10	1	1622cc, alternative	CHF 109.50
1	8G2335/20	MAINS MGA 1622 +20	1	1622cc, alternative	CHF 109.50
1	8G2335/30	MAINS MGA 1622 +30	1	1622cc, alternative	CHF 109.50
1	8G2335/40	MAINS MGA 1622 +40	1	1622cc, alternative	CHF 109.50
2	BHM1294	THRUST SET STD 4PCS	1		CHF 22.05
2	BHM1294/5	THRUST SET+.005 4PCS	1		CHF 22.05
2	BHM1294/10	THRUST SET+.010 4PCS	1		CHF 22.05
3	AEH519	OIL SEAL REAR	1		CHF 98.40
4	1G765	SPIGOT BUSH	1		CHF 6.15
5	1G2874	RING GEAR, 120 TEETH, 10 3/4" ID	1		CHF 38.05
6	AEH541	DOWEL NCA	2		availability request (add quantity to basket, offer follows)
7	51K1022	FLYWHEEL BOLT MGA&B >65	6		CHF 18.70
8	6K26	LOCKTAB FLYWHEEL 3BRG B SERIES	3		CHF 7.30
9	FNZ506	NUT 3/8 UNF HT	6		CHF 2.75
10	51K894	STUD - MAIN END MGA	6		CHF 20.65
11	GHF335	WASHER SPRING 1/2	6		CHF 1.05
12	LNZ108	NUT 1/2 UNF AERO	6		CHF 4.65
15	BHM1212	CAM BRG SET B SERIES	1		CHF 26.40
17	12H1638	GASKET MAIN BEARING CAP, CORK	2		CHF 2.85
19	AEH556KSTD	RING SET STANDARD	1		CHF 110.35
19	AEH556K020	RING SET, 0.020"	1		availability request (add quantity to basket, offer follows)
19	AEH556K030	RING SET +0.030"	1		CHF 131.20
20	AEH690STD	PISTON SET STD MGA T/C	1	8.3:1 Comp ratio	CHF 1'025.00
20	AEH690020	PISTON SET +20 MGA T/C	1		CHF 1'025.00
20	AEH690030	PISTON SET +30 MGA T/C	1		CHF 1'025.00
20	AEH690040	PISTON SET +40 MGA T/C	1		CHF 1'025.00
20	AEH690060	PISTON ASSEMBLY SET	1		CHF 1'025.00
21	CCN214	CIRCLIP 1 IN INT BORE	8		availability request (add quantity to basket, offer follows)
22	AEH647	CON ROD BOLT	8		availability request (add quantity to basket, offer follows)
23	6K881	LOCK TAB BIG END >70	4		CHF 4.80
24	C17164	BUSH SMALL END TR CYL	4		CHF 11.30
25	8G2259STD	CON ROD BEARING SET STD	1	standard size only	availability request (add quantity to basket, offer follows)
30	AEH619	HALF SPEED SHAFT	1		availability request (add quantity to basket, offer follows)
31	AEH608	PLATE LOCATING	1		availability request (add quantity to basket, offer follows)
32	GHF117	SCREW 1/4UNF X 3/4	3		CHF 1.45
33	GHF332	WASHER SPRING 5/16	3		CHF 0.25
34	AEH454	TACHO DRIVE GEAR	1		CHF 206.25
35	WKN304	WOODRUFF KEY CAMSHAFT REAR 1/2 D X3/32	1		CHF 3.10
36	1H605	Clip, end of camshaft	1		CHF 3.60
37	AEH426	GEAR, CRANKSHAFT	1		availability request (add quantity to basket, offer follows)
38	2H326	WOODRUFF KEY CRANKSHAFT	1		CHF 5.50
39	AEH427	OIL THROWER	1		availability request (add quantity to basket, offer follows)
40	AEH449	GEAR, HALF SPEED SHAFT	1		availability request (add quantity to basket, offer follows)
41	WKN505	WOODRUFF KEY CAMSHAFT 5/8 D X5/32	1		CHF 4.55
42	WKN304	WOODRUFF KEY CAMSHAFT REAR 1/2 D X3/32	1		CHF 3.10
43	AEH451	BOLT	1		CHF 19.35
44	AEH452	GEAR WASHER	1		availability request (add quantity to basket, offer follows)
45	AEH453	WASHER NCA	1		availability request (add quantity to basket, offer follows)
50	8G2261	CAMSHAFT BEARING SET #	1	12 pieces	CHF 277.70
51	AEH412	PIVOT STUD	2		availability request (add quantity to basket, offer follows)
52	CCN108	CIRCLIP	2		availability request (add quantity to basket, offer follows)
53	AEH413	BOLT SPROCKET	4		CHF 17.60
54	SH605051	SCREW 5/16" UNF X 5/8"	2		CHF 3.10
55	AEH340	CASTELLATED NUT	1		availability request (add quantity to basket, offer follows)
56	AEH341	WASHER, LOCK TAB	1		availability request (add quantity to basket, offer follows)
57	WKN505	WOODRUFF KEY CAMSHAFT 5/8 D X5/32	1		CHF 4.55
58	AEH446	SHIM 0.002 NCA	a/r		availability request (add quantity to basket, offer follows)
58	AEH447	SHIM 0.003 NCA	a/r		availability request (add quantity to basket, offer follows)
64	AEH372	TIMING CHAIN MGA TC	1		CHF 45.20
65	AEH332	DAMPER BRACKET	2		availability request (add quantity to basket, offer follows)
66	AEH334	DAMPER CAM GEAR	2		CHF 55.00
67	CRS207	RIVET	4		availability request (add quantity to basket, offer follows)
68	GHF120	SCREW 5/16 UNF X 3/4	4		CHF 0.80
69	GHF332	WASHER SPRING 5/16	4		CHF 0.25
70	GHF201	NUT 5/16 UNF	4		CHF 0.35
75	CCN118	CIRCLIP	1		CHF 2.85
76	GHF304	WASHER 1/2 X 15/16	1		CHF 0.80
77	AEH343	WASHER, LOCK TAB	1		availability request (add quantity to basket, offer follows)
78	AEH623	NUT	1		CHF 4.55
79	AEH362	ADJUSTER SCREW	1		CHF 6.95
80	GHF208	NUT 5/16 UNC	1		CHF 0.80
81	AEH561	SPRING	1		availability request (add quantity to basket, offer follows)
82	AEH370	BOLT	2		availability request (add quantity to basket, offer follows)
83	GHF200	NUT 1/4 UNF	2		CHF 0.60
84	AEH371	WASHER, LOCK TAB	1		availability request (add quantity to basket, offer follows)
85	6K649	OLIVE VACUUM PIPE	2		CHF 1.55
86	2A459	NUT MALE, CARBURETTOR END	2		CHF 13.70
87	6K4973	SEALING WASHER	1		availability request (add quantity to basket, offer follows)
88	GHF332	WASHER SPRING 5/16	1		CHF 0.25
89	GHF201	NUT 5/16 UNF	1		CHF 0.35
90	AEH359	BANJO BOLT	1		CHF 30.40
91	AEC346	FLAT WASHER 3/8 ID	2		CHF 5.10
92	GHF101	SCREW 1/4 UNF X 1IN	1		CHF 0.80
93	GHF300	WASHER 1/4 X 1/2 OD	1		CHF 0.45
94	GHF331	WASHER SPRING 1/4	1		CHF 0.55
95	AEH360	BANJO BOLT	1		CHF 25.20
96	AEH520	WASHER, SEALING	1		availability request (add quantity to basket, offer follows)
97	AEH375	STUD	4		availability request (add quantity to basket, offer follows)
98	GHF201	NUT 5/16 UNF	4		CHF 0.35