IGNITION

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	222-555	ELECTRONIC IGNITION KIT, PERTRONIX IGNITOR, 23/24/25D4, POSITIVE EARTH	1	positive ground	CHF 314.30
NI	222-405	ELECTRONIC IGNITION KIT, PERTRONIX IGNITOR, 23/24/25D4, NEGATIVE EARTH	1	negative ground	CHF 304.40
NI	143-321	ELECTRONIC IGNITION KIT, PERTRONIX IGNITOR II, 23/24/25D4, NEGATIVE EARTH	1	Ignitor II, negative ground	CHF 430.65

Ill.no.	Partno.	Part	Quantity required	Info	Price
1	GDC102	DISTRIBUTOR CAP 4-CYL. (CONNECTIONS SIDEWAYS)	1		CHF 24.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
2	GSC111HQ	CONDENSER & LEAD, OE QUALITY 25D	1		CHF 25.95

Ill.no.	Partno.	Part	Quantity required	Price
3	GCS107	POINT SET, CONTACT BREAKER	1	CHF 16.15
3	GCS107HQ	POINT SET, CONTACT BREAKERS, HIGH QUALITY	1	CHF 27.70
3	GCS2101	POINT SET, CONTACT BREAKER	1	CHF 10.50

Ill.no.	Partno.	Part	Quantity required	Info	Price
4	GRA2101HQ	ROTOR ARM 4CYL HIGH QUALITY	1		CHF 23.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
6	SH504061	SCREW 1/4" UNC X 3/4"	2		CHF 1.00

Ill.no.	Partno.	Part	Quantity required	Info	Price
7	GHF300	WASHER 1/4 X 1/2 OD	2		CHF 0.15

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

Ill.no.	Partno.	Part	Quantity required	Info	Price
10	6K649	OLIVE VACUUM PIPE	1	Twin Cam when vacuum advance is fitted	CHF 1.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
11	2A459	NUT MALE, CARBURETTOR END	1	Twin Cam when vacuum advance is fitted	CHF 8.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
12	6K650	UNION NUT TO VACUUM LINE IGNITION DISTRIBUTOR	1	Twin Cam when vacuum advance is fitted	CHF 9.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
15	11B282	UPPER CABLE CLAMP NCA	1	Twin Cam only	availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
16	AEH624	CABLE CLAMP	1	Twin Cam only	CHF 93.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
17	SH604051	SCREW 1/4" UNF X 5/8"	2	Twin Cam only	CHF 0.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
18	GHF332	WASHER SPRING 5/16	2	Twin Cam only	CHF 0.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
19	GHF200	NUT 1/4 UNF	2	Twin Cam only	CHF 0.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
20	AEH627	CLIP HT CABLE	2	Twin Cam only	CHF 45.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
21	PCR809	P CLIP, 1/2" CABLE DIAMETER X 9/32"	1	Twin Cam only	CHF 1.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
22	ACH8529	FERRULE RUBBER	1	Twin Cam only	CHF 8.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
23	SH604051	SCREW 1/4" UNF X 5/8"	1	Twin Cam only	CHF 0.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
24	GHF200	NUT 1/4 UNF	1	Twin Cam only	CHF 0.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
25	GHF331	WASHER SPRING 1/4"	1	Twin Cam only	CHF 0.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
30	GCL101	USE GCL101UR	1	Schraubanschluss
30	GCL101UR	IGNITION COIL 12V NON BALLASTED, SCREW IN TOP	1	screw-type	CHF 114.00
30	TT2981	IGNITION COIL, SPORTS, 12 VOLT, NON BALLASTED	1	push-in HT connector	CHF 60.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
31	SH605051	SCREW 5/16" UNF X 5/8"	2		CHF 0.85

Ill.no.	Partno.	Part	Quantity required	Info	Price
32	GHF301	WASHER 5/16 X 5/8 M8	2		CHF 0.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
33	GHF332	WASHER SPRING 5/16	2		CHF 0.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
34	105036	CABLE CONNECTION SCREWED TO IGNITION COIL (THREAD LENGTH,Ø13MM)	1		CHF 2.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
35	214279A	CONNECTOR HT LEAD	1		CHF 1.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
40	3H1422	PLUG CAP SUPPRESSED	4		CHF 24.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
42	BP7ES	USE N4 CHAMPION	4
42	N4C	SPARK PLUG CHAMPION	4		CHF 13.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
44	GHT102X	HT LEAD SET OE TYPE	1	De luxe only	CHF 84.30
44			1	De luxe only

Ill.no.	Partno.	Part	Quantity required	Info	Price
46	1G2620	STRAP - COIL MOUNTNG	1		CHF 39.50

Ill.no.	Partno.	Part	Quantity required	Info	Price
47	SH604161	SCREW 1/4" UNF X 2"	1	De luxe only	CHF 2.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
48	PWZ204	USE WM57	2	De luxe only
48	WM57	WASHER, PLAIN, 1/4" ID X 3/4" OD	2	De luxe only	CHF 0.40

Ill.no.	Partno.	Part	Quantity required	Info	Price
49	GHF331	WASHER SPRING 1/4"	1	De luxe only	CHF 0.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
50	GHF200	NUT 1/4 UNF	1	De luxe only	CHF 0.20

Ill.no.	Partno.	Part	Quantity required	Info	Price
51	PWZ205	WASHER, PLAIN, 5/16" ID X 1" OD	2	De luxe only	CHF 0.35

Ill.no.	Partno.	Part	Quantity required	Info	Price
52	GHF332	WASHER SPRING 5/16	2	De luxe only	CHF 0.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
53	GHF201	NUT 5/16 UNF	2	De luxe only	CHF 0.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
1	GDC102	DISTRIBUTOR CAP 4-CYL. (CONNECTIONS SIDEWAYS)	1		CHF 24.40
2	GSC111HQ	CONDENSER & LEAD, OE QUALITY 25D	1		CHF 25.95
3	GCS107	POINT SET, CONTACT BREAKER	1		CHF 16.15
3	GCS107HQ	POINT SET, CONTACT BREAKERS, HIGH QUALITY	1		CHF 27.70
3	GCS2101	POINT SET, CONTACT BREAKER	1		CHF 10.50
4	GRA2101HQ	ROTOR ARM 4CYL HIGH QUALITY	1		CHF 23.70
6	SH504061	SCREW 1/4" UNC X 3/4"	2		CHF 1.00
7	GHF300	WASHER 1/4 X 1/2 OD	2		CHF 0.15
8	GHF331	WASHER SPRING 1/4"	2		CHF 0.55
10	6K649	OLIVE VACUUM PIPE	1	Twin Cam when vacuum advance is fitted	CHF 1.55
11	2A459	NUT MALE, CARBURETTOR END	1	Twin Cam when vacuum advance is fitted	CHF 8.70
12	6K650	UNION NUT TO VACUUM LINE IGNITION DISTRIBUTOR	1	Twin Cam when vacuum advance is fitted	CHF 9.95
15	11B282	UPPER CABLE CLAMP NCA	1	Twin Cam only	availability request (add quantity to basket, offer follows)
16	AEH624	CABLE CLAMP	1	Twin Cam only	CHF 93.30
17	SH604051	SCREW 1/4" UNF X 5/8"	2	Twin Cam only	CHF 0.40
18	GHF332	WASHER SPRING 5/16	2	Twin Cam only	CHF 0.25
19	GHF200	NUT 1/4 UNF	2	Twin Cam only	CHF 0.20
20	AEH627	CLIP HT CABLE	2	Twin Cam only	CHF 45.25
21	PCR809	P CLIP, 1/2" CABLE DIAMETER X 9/32"	1	Twin Cam only	CHF 1.90
22	ACH8529	FERRULE RUBBER	1	Twin Cam only	CHF 8.75
23	SH604051	SCREW 1/4" UNF X 5/8"	1	Twin Cam only	CHF 0.40
24	GHF200	NUT 1/4 UNF	1	Twin Cam only	CHF 0.20
25	GHF331	WASHER SPRING 1/4"	1	Twin Cam only	CHF 0.55
30	GCL101	USE GCL101UR	1	Schraubanschluss
30	GCL101UR	IGNITION COIL 12V NON BALLASTED, SCREW IN TOP	1	screw-type	CHF 114.00
30	TT2981	IGNITION COIL, SPORTS, 12 VOLT, NON BALLASTED	1	push-in HT connector	CHF 60.40
31	SH605051	SCREW 5/16" UNF X 5/8"	2		CHF 0.85
32	GHF301	WASHER 5/16 X 5/8 M8	2		CHF 0.30
33	GHF332	WASHER SPRING 5/16	2		CHF 0.25
34	105036	CABLE CONNECTION SCREWED TO IGNITION COIL (THREAD LENGTH,Ø13MM)	1		CHF 2.70
35	214279A	CONNECTOR HT LEAD	1		CHF 1.20
40	3H1422	PLUG CAP SUPPRESSED	4		CHF 24.75
42	BP7ES	USE N4 CHAMPION	4
42	N4C	SPARK PLUG CHAMPION	4		CHF 13.75
44	GHT102X	HT LEAD SET OE TYPE	1	De luxe only	CHF 84.30
44			1	De luxe only
46	1G2620	STRAP - COIL MOUNTNG	1		CHF 39.50
47	SH604161	SCREW 1/4" UNF X 2"	1	De luxe only	CHF 2.05
48	PWZ204	USE WM57	2	De luxe only
48	WM57	WASHER, PLAIN, 1/4" ID X 3/4" OD	2	De luxe only	CHF 0.40
49	GHF331	WASHER SPRING 1/4"	1	De luxe only	CHF 0.55
50	GHF200	NUT 1/4 UNF	1	De luxe only	CHF 0.20
51	PWZ205	WASHER, PLAIN, 5/16" ID X 1" OD	2	De luxe only	CHF 0.35
52	GHF332	WASHER SPRING 5/16	2	De luxe only	CHF 0.25
53	GHF201	NUT 5/16 UNF	2	De luxe only	CHF 0.45
NI	222-555	ELECTRONIC IGNITION KIT, PERTRONIX IGNITOR, 23/24/25D4, POSITIVE EARTH	1	positive ground	CHF 314.30
NI	222-405	ELECTRONIC IGNITION KIT, PERTRONIX IGNITOR, 23/24/25D4, NEGATIVE EARTH	1	negative ground	CHF 304.40
NI	143-321	ELECTRONIC IGNITION KIT, PERTRONIX IGNITOR II, 23/24/25D4, NEGATIVE EARTH	1	Ignitor II, negative ground	CHF 430.65