STEERING & SUSPENSION

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	WKN506	WOODRUFF KEY 3/4D X 5/32	2		CHF 3.10

Ill.no.	Partno.	Part	Quantity required	Info	Price
2	GHF226	NUT-NYLOC FULL 5/8NF	2		CHF 4.95

Ill.no.	Partno.	Part	Quantity required	Info	Price
3	PWZ110	WASHER, PLAIN, 5/8" ID X 1.1/4" OD	2		CHF 2.05

Ill.no.	Partno.	Part	Quantity required	Info	Price
5	GHS211	OIL SEAL MGA/B BANJO	2		CHF 7.70

Ill.no.	Partno.	Part	Quantity required	Info	Price
6	GHB105	BEARING TIMKEN	2		CHF 24.20
6	GHB105Z	BEARING FRONT B REAR GT6	2	aftermarket	CHF 29.45

Ill.no.	Partno.	Part	Quantity required	Info	Price
7	BTB183	COLLAR FRONT OIL SEAL	2		CHF 33.75

Ill.no.	Partno.	Part	Quantity required	Info	Price
9	88G484	SPACER FRONT HUB BRG B	2		CHF 21.55

Ill.no.	Partno.	Part	Quantity required	Info	Price
10	GHB102	BEARING FRONT JAG B&AH	2		CHF 27.40

Ill.no.	Partno.	Part	Quantity required	Price
11	ATB4240	SHIM 0.003IN FRONT HUB	a/r	CHF 1.90
11	ATB4241	SHIM 0.005IN FRONT HUB	a/r	CHF 1.90
11	ATB4242	SHIM 0.010IN FRONT HUB	a/r	CHF 1.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
12	1A4742	WASHER RETAINING, FRONT HUB	2		CHF 4.25

Ill.no.	Partno.	Part	Quantity required	Info	Price
13	53K330	NUT, CASTLE HEAD	2		CHF 16.90

Ill.no.	Partno.	Part	Quantity required	Info	Price
14	BTC392	GREASE CAP WIRE WHEELS	2		CHF 8.30

Ill.no.	Partno.	Part	Quantity required	Info	Price
15	AHH5789PR	SPRING PAIR SICR MGBGT TO 1972 MGA TWIN CAM 480 LB	1	(Silicon chrome) - pair - Twin Cam reconditioned	availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
20			1	Twin Cam reconditioned
20			1	Twin Cam reconditioned

Ill.no.	Partno.	Part	Quantity required	Info	Price
21	AHH6036	STEERING PINION, RHD	1		availability request (add quantity to basket, offer follows)

Ill.no.	Partno.	Part	Quantity required	Info	Price
1	WKN506	WOODRUFF KEY 3/4D X 5/32	2		CHF 3.10
2	GHF226	NUT-NYLOC FULL 5/8NF	2		CHF 4.95
3	PWZ110	WASHER, PLAIN, 5/8" ID X 1.1/4" OD	2		CHF 2.05
5	GHS211	OIL SEAL MGA/B BANJO	2		CHF 7.70
6	GHB105	BEARING TIMKEN	2		CHF 24.20
6	GHB105Z	BEARING FRONT B REAR GT6	2	aftermarket	CHF 29.45
7	BTB183	COLLAR FRONT OIL SEAL	2		CHF 33.75
9	88G484	SPACER FRONT HUB BRG B	2		CHF 21.55
10	GHB102	BEARING FRONT JAG B&AH	2		CHF 27.40
11	ATB4240	SHIM 0.003IN FRONT HUB	a/r		CHF 1.90
11	ATB4241	SHIM 0.005IN FRONT HUB	a/r		CHF 1.90
11	ATB4242	SHIM 0.010IN FRONT HUB	a/r		CHF 1.90
12	1A4742	WASHER RETAINING, FRONT HUB	2		CHF 4.25
13	53K330	NUT, CASTLE HEAD	2		CHF 16.90
14	BTC392	GREASE CAP WIRE WHEELS	2		CHF 8.30
15	AHH5789PR	SPRING PAIR SICR MGBGT TO 1972 MGA TWIN CAM 480 LB	1	(Silicon chrome) - pair - Twin Cam reconditioned	availability request (add quantity to basket, offer follows)
20			1	Twin Cam reconditioned
20			1	Twin Cam reconditioned
21	AHH6036	STEERING PINION, RHD	1		availability request (add quantity to basket, offer follows)