RP Saloon Technical Information
This page is revised / updated / corrected when information becomes available.
It is intended to have links to illustrations, drawings and pictures as the site progresses If you can help, please do.
The following information was initially gathered by Sandy Croall from a number of sources, some of it conflicting in details, some vague. (Acknowledgements will be listed, soon). The information below is presented in good faith, Errors and Omissions Excepted (E&OE.)
Page last updated 21 December 2003
Note - A word of caution – For those who insist their car is original! It should be remembered that the availability of parts, and the longevity of the Austin 7, allowed easy swapping and changing of parts, especially when the vehicles were 25 – 30 years old in the 1950’s and early 60’s. It was easy then to pop into the scrap yards that existed and pick up a spare part for ‘pennies’ – a lifetime ago now, but in those days you could buy a ‘runner’ for a fiver (£5). My first RP cost £4.4s 3½d. The 4s 3½d (21½p) was for the gallon of petrol the seller put in to get me home!
Some parts on my current RP are dated circa 1952, this is when the car was sold to it’s second owner and presumably some replacements were needed, and still available then.
I am aware of an RP saloon, produced in late ’33, which had a number of ‘non-standard’ parts replaced in late ’34 after the driver, a ‘Rep’ pranged the car. Tracking down every owner after the ‘Rep’ showed the car had never been altered, so it was thought the parts were original and fitted in late ’33. It is now accepted, the Rep had a prang, nothing changes.
The
RP Saloon was manufactured between Oct. 1932 and July 1934 starting with Car No.
B6 – 5934 and then a few in number until full production commenced from chassis
number 162,600 (Car No,
B6-6000) to 198,595 (Car No. C1 - 2300). The total production of RP Saloons is
believed to be approximately 23,000 of which approx. 3,000 were ‘Standard’
saloons. It should be noted that the engine numbers
were approximately 500 to 1,000 greater than the chassis number. The earliest surviving RP is thought to be chassis 162,651,
Car No. B6-6055, Reg No. LJ 6488 although the surviving
chassis 162,566 may
be an RP - (awaiting verification). The last surviving RP Saloon in the Register
is
chassis No. 198,566 Reg No. AHU 768, registered on 2/7/34. ( AC7A Register of Surviving Cars
(2000 edition)
The RP was the last Chrome Radiator Saloon model to be manufactured and looked visually similar to the
previous RN Model, including a rear mounted fuel tank.
The principle and easiest way to distinguish the RN from the RP is the bakelite cover to the ‘GAS’ and ‘IGN’ levers on the steering column, however it appears a few RN’s where fitted with these as well! It is believed all RN’s had the battery box under the passenger seat, RP Saloons had the battery box under the drivers seat.
Externally the upward flow of the waist moulding from the scuttle to the front window /door pillar is the most obvious.
The Source book states RN doors are 33” wide and RP’s 33¼” , but the RN’s and RP’s I’ve measured are all 33 5/16” wide. The RN door is 1/16” thicker at the bottom. Thus although RP doors will easily fit RN’s, RN doors stick out at the bottom.
The RN doors and rear side windows have parallel moulding line on all four sides of the opening.
The RP moulding along the bottom edge widens in the middle by about ⅛”. There are numerous observations (Scone 2003, Beaulieu 2003) of RN / RP doors being used on the other model Saloon (and on Vans).
Many thanks to Dave Tedham (Scottish A7 Club) via Dave Mann (RN Register) for the ‘moulding’ information.
If the sliding sun-roof is still fitted, the RN sliding roof is contained within the roof line, the RP sliding roof overlaps the roof panels. Excellent drawings by Phil Baildon of both the RN and RP sliding roof details can be found in ‘The Source Book’.
RP Sliding Roof
Most of the improvements incorporated in the RN Saloon in Sept 1932 formed the
basis of the RP Saloon and therefore it is worth starting the Chronological
changes at this point with :-
RN Saloon
Chassis number 159,534, Car No. B6-2938 Sept. ’32
New features include: - A four-speed "twin top" gearbox, M35 starter motor and Lucas ST9 switch on off side of engine. Induction and exhaust now combined in one manifold casting, with a Zenith 26VA side draught carburettor, the choke (or strangler!) was not connected to the throttle linkage. Rear petrol tank. An AC ‘M’ fuel pump (type without a priming lever), is fitted to the nearside of engine - Note the inlet hole is on opposite side from petrol tank. A new instrument panel, always painted black, is situated behind the Steering column on the dashboard incorporating from left to right, a Lucas PLC 5 Ignition switch with ‘spade’ key, Lucas C213/A17 Ammeter with a Lucas WL3 Ignition light below, a Smiths ‘Magmo’ moving dial speedometer with Lucas dash lamp above it, a Harcourt oil pressure gauge and a Smiths petrol gauge. One large glove compartment was situated on the passenger side of the dashboard. The dashboard was painted the same colour as the main bodywork colour. Wider brake drums front and rear with improved controls. Plated radiator cap with a quick release type fixing. Engine and Radiator moved forward approx. one inch to accommodate four speed box. Lever on brakes modified. Clutch withdrawal system modified to ease lubrication. Lucas 30G Vacuum wiper fitted.
RP Saloon October 1932
Chassis Number 162,600 B6-5934, B6-6000.
There were minor changes to the bodywork, it was made an inch narrower across the back seat area and the front window / door frame incorporated a swept curve upwards from the scuttle raised waist moulding. The sliding roof on De Luxe cars had modified Pytchley sliding gear. The ‘GAS’ and ‘IGN’ levers on top of the steering column are covered with a bakalite moulding. Lucas 'Little Trafficator' indicators, Model SE 26 fitted as standard. [Note: In Rinsey Mills ‘The Original Austin Seven, it is stated the Ruby was first fitted with built-in Trafficators, first the SE 26 …., but my RP’s external type are definitely marked SE26]. During the production period the RP door window winders changed from Hobson-Perfect type to a Lucas design with a separate Escutcheon plate. It may be that the rear window blinds were introduced as a standard fitting at this time, although many surviving cars show no signs of having them fitted originally. Throughout the RP Saloon production period the Lucas DJ4 manual Advance / Retard Distributor was fitted. A Rist Horn was fitted as standard and it is believed that armoured cabling was used throughout the RP's manufacturing period.
Note: Illustrations 898 and 901 in ‘The Source Book’ within the RP text are in fact RN Saloons. The only RP shown is illustration 897, Mike Jarrett’s Dec. ’33 RP.
Chassis No. 167,588 January 1933
Petrol pipe unions and joints of new ‘Austin’ design to obviate previous air leaks.
Engine No. 168,230 January 1933
Outside diameter of camshaft rear bearing increased.
Chassis No. 170,810 March 1933
Torque tube ball seating
Engine No. 174,921 April 1933
New design of piston fitted, distinguished by row of oil drain holes drilled in the bases of the two lower grooves and the use of two slotted and one plain ring per piston. There is no ring below the gudgeon pin, as in the type superseded. Low expansion alloy used.
Chassis No. 175,450 April 1933
Lower end of the change speed lever increased in diameter to provide greater strength and all adjoining parts increased in size to suit.
Chassis Number 176,687 June 1933
Hardy Spicer type rear universal joint fitted.
Chassis No.179,368 August 1933
Standard equipment now includes improved dip switch and Lucas LB 130P headlamps with sidelight bulb below main bulb fitted (replacing the Lucas R47 headlights with sidelight above main bulb) with mottled glass [I am still trying to find out when ribbed glass is first fitted] and a corresponding Lucas FS12F foot operated dip switch. A Single Lucas ST38A stop / tail lamp was fitted [replacing the Lucas T101] together with a Lucas 39C brake light switch fitted to the cross member and foot brake rod.
[My Feb ’34 RP had the steering column dip switch (Austin Part No. BG199, Lucas Part No. 9BN) as original equipment plus a floor dip switch, but I have been unable to establish yet if the floor switch is original – there is not a floor dip switch listed in the ‘List of Spares’ Austin Publication No. 1029B, for chassis Nos. above 180,000].
A sun visor provided for the driver on De-Luxe Saloons only.
Spare wheel provided with a cover on De-Luxe Saloons only.
Rubber Engine mountings now fitted. The lower washer for these bolts is welded to the frame side members.
Engine provided with slightly higher compression cylinder head. [Details being sought] 3rd & 4th gear synchromesh gearbox fitted.
Chassis No. 179,525 September 1933
Resistor / Fuse box on top of the C35A type dynamo removed and wiring altered, fuse and 'half charge' resistor now contained within Lucas type SB5 ( model L206V ) Cutout / Fuse box on the bulkhead.
Chassis No. 180,000 September 1933
Steering box now made of special aluminium fitted to frame by bolts.
Chassis No.183,595 November 1933
Engine rubber mounting setscrew replaced by a stud and split pin.
Engine No. 190,766 December 1933
Double purpose front crankshaft bearings (also fitted to engines 188,331 – 189,499) replaced ball and roller bearings.
Chassis No. 190,001 February 1934
Slightly stiffer rear springs fitted on the offside of the chassis only.
Chassis No. 193,882 April 1934 Car No. B9 – 7590
Export cars fitted with gauze type carburettor air cleaner.
Chassis No. 193,954 April 1934
Export cars equipped with larger front shock absorber. Circa this period, 26VA Carburettor modified to include a throttle opening linkage to the choke flap. It also seems that the Rist Horn may well have been replaced by either the Lucas Altette, or the similar looking, but cheaper Clear-Hooters Ltd Horn (this seems to be original equipment on my RP, Chassis No. 189785), and the armoured cabling may have been replaced with a fabric covered loom prior to being used on the Ruby Saloons ( Subject to verification )
Chassis No.195,100 April 1934
Joint between exhaust pipe and silencer front end modified.
Chassis No. 196,274
‘C’ series of Car Nos. commenced.
Engine No. 198,747 June 1934
Improved A.C. fuel pump, type 'T' (with priming lever), fitted and connecting pipes modified - the inlet and outlet holes are reversed, the outlet pipe to the Carburettor Banjo joint is shorter, thus you cannot connect the 'T' type pipe to a 'M' pump, it's not long enough.
Chassis No. 198,566 June 1934
Last known surviving RP saloon Chassis No. 198,556, Reg No. AHU 768, Registered 2/7/34 (A7CA Register, 2000 ed.)
Chassis No. 198,595 July 1934
Last RP chassis (subject to verification, first Ruby was 198,596).