Welcome to the Swallow Doretti Page which was set up to encourage the maintenance, running and preservation of Swallow Doretti sports cars. The website aims to provide historical articles, anecdotes, tips and technical information to Doretti owners around the world.
About the Swallow Doretti Register
Established in 1975, the Swallow Doretti Register is an independent group of owner enthusiasts that operate under the auspices of the TR Register. Our primary aims are to help other Doretti owners stay “in the know”, on the road and spread the word about this rare British classic sports car.
A brief history of the Swallow Coachbuilding Company that began its life as the Swallow Sidecar Company and eventually evolved into Jaguar Cars Ltd.
The Swallow Gadabout was a British motor-scooter that pre-dated the Italian Vespa and Lambretta scooters that became very popular in the 1950’s.
Frank Rainbow the designer of the Doretti was a very competent and experienced engineer, who had worked for many years as a senior engineer at the Bristol Aircraft Company.
The Swallow Doretti is a rare 1950’s British sports car designed by Frank Rainbow and built by the Swallow Coachbuilding Company of Walsall.
Monkspath Garage located in Shirley near Solihull, was a source of Doretti parts for many years after the factory ended the production of cars.
Kenmar Shirley – a fibre-glass special sold by Monkspath Garage, based on a Ford chassis and running gear. The vehicle was probably the first post-war kit car.
Dorothy Deen was the person who provided a lot of the energy that made the Doretti and Triumph sports cars a major success on the American west coast market.
The Swallow Doretti International Vehicle Register is a comprehensive archive of Doretti sports cars.
Country No. of Cars Country No. of Cars
New Zealand 7
Republic of South Africa 1
United Kingdom 66
U. S. A. 57
Total Number of Cars Identified 184
The following items are by the authors in bold print.
REAR AXLE – Alan Gibb
The Doretti rear axle is a hypoid semi-floating type with a pressed steel cover at the rear of the central casing. This removeable cover allows access to the differential unit and crown wheel/pinion set. This axle is the same type as used on the Triumph TR2 which was itself an uprated Mayflower unit. Most problems involve half-shafts breaking at the differential end, or oil leaking at the hubs and ruining the brake linings.
If replacement half-shafts from another car are to be fitted; only use a half-shaft from the same side. DO NOT use a half-shaft from the opposite side as this will create “torque” in the reverse direction and lead to failure in a very short time. Half-shaft nuts should be tightened to 145 lbs/ft.
Whenever a half-shaft is replaced always replace the bearings at the same time as these are single row ball-bearings and take a lot of stress. Bearing lubrication is via grease nipples located at each end of the rear axle.
The complete rear axle can be exchanged for a more robust later type axle found on the TR3/3A. This axle can be identified by its round tube end flanges with six bolts holding the brake back-plate. Fitting this axle requires using the TR3/3A U-bolts and lower spring-plates to accomodate the larger axle tube diameter. This axle has Girling brakes instead of the original Lockheed items, which means that a new flexible hose is required to match it up with the original tee-piece. Remember to transfer the handbrake cable stop bracket from the old axle to the replacement unit, and it is also adviseable to replace the wheel cylinder rubbers to keep the system clean.
The rear axle number is stamped on the upper rim of the flange to which the rear cover plate is attached. This number has the prefix “TS”.
Technical Notes and Parts Information
Specification and Performance Data
Type Two-seater open sports
Number of doors Two
Type 4 cylinders inline
Pushrod operated OHV
Bore × stroke 83.00mm × 92.00mm
3.27 in × 3.62 in
Bore/Stroke ratio 0.9
Displacement 1991 cc
(121.498 cu in)
Compression ratio 8.5:1
Carburettor Type Twin S.U. (type H4)
Ignition System Lucas coil and distributor
Max. output 90.0 bhp (67.1 kW)
Max. torque 159.0 nm (117 lbft) (16.2 kgm)
Specific output 45.2 bhp/litre
0.74 bhp/cu in
Dimensions & Weights
Wheelbase 2413 mm 95 in
Track Front 1219 mm 48 in
Rear 1155 mm 45.5 in
Overall length 3962 mm 156 in
Overall width 1384 mm 54.5 in
Overall height 1295 mm 51 in
Ground clearance 152 mm 6 in
Curb weight 864 kg 1905 lb
Weight distribution Front/rear 52/48%
Fuel capacity 56.8 litres 12.5 gallons
Engine location Front
Engine alignment Longitudinal
Steering Bishop Cam
Steering lock 2.5 turns, lock to lock
Turning circle 33 feet (11m)
Suspension Front Coil spring & wishbone
Rear Semi-elliptic leaf springs
Brakes Front 10in.×2.25in.drum
Braked area 148sq.in.
Wheels & Tyres Disc or wire / 5.50×15
Transmission 4 forward & reverse
Overdrive 22% step up
Top gear ratio 0.82
Final drive ratio 3.70
WINDSCREENS – Maurice Ford
FRAMES -There are two types of windscreen frame:
a) Early type with externally visible channel fixing screws and thumb screw type hood retainers and
b) Late type with internal channel fixings and ‘clip type’ hood rail fasteners. The hood locating pegs, are, incidentally, farther apart than the earlier type so that an early hood will not fit a late car and vice versa. The late type frame has the uprights set farther out the bottom, relative to the mounting feet, by a good inch and at a different angle so that at the top it is only 3/4 inch or so wider than the early frame. This late frame is also higher by about 1/2 inch.
GLASS – Glass for the early ‘small’ frame still available as Pilkingtons still have the jigs. Their agents (AutoWindscreens) will obtain one from them at around £200. The late type is NOT available off the shelf and Pilkington/Triplex do not recognise it as being made by them. The early type screen will not fit! The only way is to have one cut from a modem equivalent by a competent screen company (I acquired mine from Tamworth Autoscreens who were very helpful) and let them have the frame so that they can fit it. Do not get the screen before you decide on the seals. See below.
SEALS – For early screens the seal is no longer available. Since the glass does not enter very far into the channel the seal is rather odd. It can be made up by using Edgware seal 319 and bonding/glueing L3 to its base.
For the late screen you have a choice – either make up a seal as above and have the screen cut to fit this or cut the screen to fit deep into the channel with comers notched to clear the frame fixing brackets (as MGB) and use rubber seal 325 bedded in silicon.
This last method looks a lot neater but there is a snag. The glass will not stand any serious frame deflection during fitting – I suspect that this is the reason why the original method was used during production, particularly since the method of fixing the screen frame to the body is not very clever. When fitting it is essential that packers are used between the screen frame feet and the body to ensure that these fit exactly each side and will tighten down without fouling the scuttle as it rises up over the dash. If it fouls here it will push the frame outwards at the bottom and try to stretch the glass. Failure to be diligent when fitting the screen and frame to the body will cause you another trip to the screen maker.
I hope that the above is of some use to other Doretti owners but if anyone needs further info they are welcome to contact me.
LUCAS WIRING COLOUR CODE
Black All ground connections
Black / Green Relay to radiator fan motor
Blue Headlight switch to dimmer switch
Blue / White Headlight high beams
Blue / White High beam dimmer switch to indicator lamp
Blue / White Dimmer switch to long-range driving light switch
Blue / Red Headlight low beams
Brown Main feed from the battery. No switches or fuses
Brown / Yellow Generator to voltage regulator
Brown / Blue Power feed to headlamp switch
Brown / White Ammeter to main alternator terminal
Brown / Yellow Long-range driving light switch to lamp
Brown / Yellow Alternator to ‘no charge’ warning light
Brown / Purple Alternator regulator feed
Brown / Green Fuse to horn (No relay)
Brown / Black Horn to horn button (no relay)
Green Ignition circuit, additional switches or fused
Green / Black Fuel gauge to fuel tank unit
Green / Blue Water temperature gauge to temperature sender unit
Green / Red Direction indicator switch to left-hand flasher lamps
Green / Purple Stop lamp switch to stop lamps
Green / White Direction indicator switch to right hand flasher lamps
Green / Yellow Heater switch to heater motor
Light green / Blue Flasher switch to left-hand flasher warning light
Light green / Brown Flasher switch to flasher unit
Light green / Purple Flasher unit to flasher warning light
Purple Accessories fed direct from battery via fuse
Purple / Brown Horn fuse to horn relay when horn is fused separately
Purple / Red Switches to map light, under bonnet light, glove box light and boot lamp when fed direct from battery fuse
Red Tail lights, instrument lights and side markers
Red / Yellow Fog light switch to fog light or fog light fuse to fog lights
Red / Blue Front fog light fuse to fog light switch
Red / White Fuse to instrument lamp switch, Instrument panel lamps
White Ignition circuit, no additional switches, not fused
White Power to coil
White / Black Ignition coil to distributor
White / Brown Oil pressure switch to warning light
White / Pink Ignition switch to radio fuse
White / Red Ignition switch or starter switch to starter solenoid
Yellow Generator connections wired through the ignition switch
Yellow / Green Dynamo ‘F’ to controlbox ‘F’ Alternator field ‘F’ to control box ‘F’
More to follow………………………………….but not tonight………………. sorry!