Here you will find some technical information's

front cover 1B3338

front cover 1B3338 with radial seal

Oil pressure switch

Thread for Oil gauge:


I have on the engine block 1/4" BSP female and the oil pressure pipe ends with 1/" BSP male.

Inbetween is an flexible hose with female ends. To get the female end of the flexible hose to the engine, an adapter with two male ends is fitted.

I have fitted an electrical fuel pump on my A90 Atlantic, therefore a oil pressure switch must be available for security reason.

I bought an oil pressure switch on ebay (thread 1/8 NPD) but the t-Adapter is the problem. I couldn't find one with 1/4" BSP on both ends, only 1/8" BSP is available (~ 10 GBP).


to be continued....

Starting motor

Lucas - type M418G, L-3


The distributer for the A90 Atlantic is: Lucas - type DVX4A

in one of the earlier service book (June 1950) I found DK7.4A.

later Lucas DM2 (P4)


later type starts May 1951

Service number = 40320A/B

rotation = ClockWise

ECM curve = 430

Model = DM2P4

RPM 1 = 2500 / Advance1 (± 1°) = 17°

RPM 2 = 1250 / Advance2 (± 1°) = 9°

RPM 3 = 600 / Advance3 (± 1°) = 2°

no advance below = 325years = 1949-52

make = Austin, Austin Healey


models = 1949-1952
Austin A90 Atlantic, 1953-56 Austin Healey 100-4 BN1/2

Comments = superseded by 40495

Ignition coil

Lucas - type B12

Spark Plug

Anzugsdrehmomente für Zündkerzen mit flachem Sitz(mit Dichtung):        
  18 mm 14 mm 12 mm 10 mm
Gußeisenkopf 35-45 Nm 25-35 Nm 15-25 Nm 10-15 Nm
Aluminiumkopf 35-40 Nm 25-30 Nm 15-20 Nm 10-12 Nm

The sparking plugs fitted to the A90 Atlantic is the long reach 14 mm type "Campion NA8"


I have a N5C on my A90 Atlantic


Austin A90 Atlantic is fitted with two

SU H4 carburettors.

(AUC 537, 2660 cc)

Tyres & Tubes & Pressure

I bought now (March 2010) new tyres from Munich (

There is a Radial tyre made by Michelin. I choose the radial type instead of the diagonal type for security and comfort, the price was nearly the same as for the diagonal type.

Michelin X-Stop

5.50x16 X-Stop

Marke: Michelin
Dimension: 5.50R16 H(84) (175/80R16)
Tragfähigkeit: 500 kg
Zul. Höchstgeschw.: 210 km/h
Max. Breite: 175 mm
Max. Höhe: 685 mm

The correct tube for the A90 Atlantic convertible rim is the TR-15 one.

Tube TR-15

The TR-13 also fits, because its smaller, but to avoid movement of the tube, the TR-15 should be taken.

Tube TR-13

Recommended Tyre Pressure:        
  2 Passengers   Full loaaded  
  Front Rear Front Rear

26 lbs./inch²

1,79 bar

26 lbs./inch²

1,79 bar

26 lbs./inch²

1,79 bar

28 lbs./inch²

1,93 bar


valve clearance = 0,3mm


Dynamo for the Austin A90 Atlantic:


Lucas - Type C45 PV3 (early type)

Lucas - Type C45 PV4 (later type)

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