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Home Restoration.
Australian Morris Cooper S Electrical Specs Part 2..
This paper is not a how-to guide on rebuilding your car. It merely represents a collection of reference and detail points specific to one model, the Australian built Cooper S, which was eventually classified as the Mark 1. Hopefully this will help to preserve a car that was and still is an interesting part of international motoring history.
Gauges:
The lavish array of gauges found in this model; speedometer, oil pressure, temperature and fuel, are all of British manufacture. Unlike the rest of the Australian range, a local speedometer would not arrive until the Mk 2 ‘S’. Apart from the obvious Made in UK stamped into the case, British gauges have an almost black face, whereas local Smiths products are deep grey. Many surviving ‘S’ speedometers have become a composite of local and imported parts and are usually only worth buying if the face is intact. The important speedo to own for the Mk 1 ‘S’ indicates a top speed of 120 MPH, with slashes up to 130 MPH. Warning light apertures are; red - ignition, blue - high beam, amber - oil filter, amber - unused. There is no provision for indicators because of the style of trafficator stalk used. The oil filter light is connected to a crimped-in switch in the Purolator oil filter head and glows if the filter bypass valve opens. No oil pressure light or switch was fitted. A popular and common sense modification is to fit a T-piece to the oil pressure outlet and run an oil pressure switch as well as the gauge. This can replace the oil filter light through the existing wiring, or be wired to the unused amber hole.
Every speedometer bears a serial number stencilled on the inner face, this code indicates the final drive ratio that the gauge was intended to match ie. SN 4417/18 is intended for a 3.44:1 final drive. Most British microfiche covering this period and Parnell 1993 (Original Mini Cooper & S) provide a comprehensive list of serial numbers and ratios.
The Smiths UK voltage stabiliser BR 1305/00A with 4 male Lucar connectors was fitted to all the British speedometers. The present replacement BR 1309/00, has 2 male and two female connections in order to prevent improper wiring. This later part first appeared locally in the mid seventies with the Moke, when the Smiths Australia speedometer was replaced with an imported unit. In both cases the stabiliser is attached to the rear of the speedo at the earth point. Earlier Australian Coopers (Non ‘S’) utilised non stabilised gauges which required a different temperature sender unit, Unipart # GTR 102. For general use with stabilised gauges use Unipart sender unit # GTR 104. Both these senders are in brass, not steel as with Smiths units. Both two inch gauges fitted to the ‘S’ were distinguish by long mounting studs, almost as if they were intended for a wood dash. The temperature gauge can also be identified by a red mark at the hot end of the face. The fuel gauge is attached to the back of the speedo case by two fine thread screws. Tank units for this era appear to be a local Smiths product and fitted to the tank prior to painting. All tank units were retained by a locking ring and had two male Lucar connections (one standard, one small).
The oil pressure gauge is mechanical not electrical and is connected to the engine via two steel pipes and one thick walled, reinforced rubber hose. This hose is secured by two hose clamps of the flat strap, nut and screw variety. The hose is still available new from certain suppliers, but a slightly longer equivalent can be readily sourced from any Austin Freeway.
The Mk 1 ‘S’ range utilised the standard (base model) speedometer support binnacle which was produced in cream/bone plastic. This part suffers severely from cracking and is hard to obtain in good condition. The first Australian Mini Vans provided a black equivalent and this part remained in production until the early eighties with the end of the British Van and Pick Up models. Japanese Mini specialists manufacture an exceptional copy of the cream/bone binnacle in fibre glass; though they still require the two side holes to be drilled and are of course thicker than the original. In order to mount the Oil and temperature gauges the Mk 1 ‘S’ utilises separate support brackets and black oval trim with a chrome surround. It would not be until the Mk 2 (K) era that the one piece plastic binnacle was fitted. Assessing whether a binnacle is correct is easily done, as the later, one piece plastic binnacle was mounted via six, 10-32 UNF screws into six captive nuts, which were spot welded into the bulkhead panel; not self tappers as is often found today. Early cars with the multi piece assembly only utilised the four thread screws and nuts as found on any base model.
Ignition:
The Lucas 23D4 distributor (refer distributor list) and HA12 coil (45132) provided the ignition source prior to the local 29D4 (62941090A) and coil (62941019 or 62941095). Both distributors are distinct in not having a vacuum advance unit, nor provision for their fitment. A point for those using Lucas books, although Mini distributors are considered to rotate anti-clockwise as viewed from the rotor button, Lucas view all distributors from the drive dog, therefore rotating clockwise.
For the earlier British distributor, BMC parts books indicate two distinct ignition lead lengths, plus the coil lead. I haven’t yet found a guaranteed unplayed with set to get accurate measurements from, but so far it would appear that leads one and two are 11Ó and three and four between 8Ó and 10Ó, plus plug terminals. Ignition lead was and still is available in length, in the original green finish; as well as the necessary terminals which include the brass staples, brass anchor for the cap end and reproduction Champion plug caps. Plug caps for the early leads are of black rubber with Champion embossed into three upper faces, none of these were painted white. Like earlier hard caps, a slip-on sealing boot was fitted to each lead prior to the plug cap. Each plug lead also had a small yellow band indicting it’s cylinder number. The coil lead has a push on connector, not an acorn nut and washer. Ignition coils remained unpainted and fitted with a rubber waterproofing boot and were mounted on top of the C40 Dynamo.
Although the Lucas side entry distributor cap came with a rubber protective boot, this piece of 1950s technology still directs water down the lead and into the cap, especially after age and oil hardens the waterproofing boot. Other present day problems with side entry caps are that they only accept 7mm cable, when the current standard is 8 & 9mm. This is a chronic problem with some kits that supposedly fit this model Mini. There is however, a better choice for every day use. At the end of the 60s Lucas introduced a direct replacement cap with provision for push on ignition leads. This cap did find its way to Australia on some Land-Rovers and Cortinas and is still readily available today, often at a far less cost than its predecessor. Fitting of this cap will require leads with right angle terminals.
In place of a modified cap, Lucas Australia introduced the 29D4 model distributor. As several car manufactures sought to increase local content at the time, this model became widely used. Mk 1 Minis received the 29D4 distributor towards the end of the range in 1968. The exact change point is not recorded but Parts list PUB 1056M indicates that for the ‘S’, It occurred within the 9F/Sa/Y engine prefix. One major drawback with the 29D4 is it’s increased size. Though not a great problem in the Mini, when fitted to other local products like the MGB, it caused no end of drama to repairers. While in production and for many years after, these distributors were reliable and parts relatively cheap. However, now that Lucas in Australia is becoming a distant memory, most repair parts are virtually unobtainable. Unique service items such as the cap and rotor still abound, as do points, condensers and drive dogs which are common with UK distributors. Bushes, spindles, base plates, bodies and low tension leads are a problem. Worn 29D4 distributors develop a distinct rattle as the weights rock on their spindles.
Though countless distributors will directly interchange with both types of ‘S’ unit, the ‘S’ as with most models, has a distinct advance curve. Presuming a distributor works because it fits and the car runs is unwise. Other distributors can be modified to suit an ‘S’, but this modification takes skill and infinite patience and thus is rarely performed and often ignored. For those who do comprehend this importance I located one handy part. Moss Europe sell a spring kit for the B-series range. The kit comes with six springs of various tensions and is inexpensive. One spring is close to British ‘S’ specification and another, Australian. Both springs represent a good starting point and can be modified with relative ease. Before you run down to your Moss agent asking for Mini springs, remember; this kit is Not for a Mini and the springs are Not directly interchangeable.
Plug leads for the 29D4 were nondescript with hard plastic plug connectors and an in-line suppressor fitted to the coil lead. As the distributor cap for this model has push on posts, leads had right angle fittings. No ignition shield was fitted, except for the rubber boot protecting the coil. A wide variety of sparking plugs were available and utilised depending on the state of tune of your Cooper ‘S’ engine. The relevant ST parts list provides a reasonable guide in addition to the standard Champion N9Y sparking plug.
As supported by Vizard (1977, How to Modify your Mini), the ‘S’ was fitted with 32 ounce points in place of the standard 24 ounce part. However, BMC Parts List 1056M indicates that with the advent of the local 29D4 Cooper ‘S’ distributor, the standard GL19 points set is used. The general rule to identifying 32 ounce points is; Lucas Made in England stamped into the base-plate and the points supplied in kit form; whereas the standard points usually come assembled, ready for fitting.
For any Mini fitted with a generator, Leyland Australia would eventually design an effective ignition shield kit, HYL 4234. This can be fitted to cars with alternators, but requires a custom mounting bracket, it also requires trimming in order to miss the ‘S’ oil cooler. The only draw back is the extra air flow directed over the rocker cover, which can freeze your SU on a cold winter’s trip to Hay.
Fuel:
The Skinners-Union (SU) fuel pump was fitted to this model. However, depending on which parts book you read, there was up to three different pumps fitted; AUF 201, AUF 204 or AUF 214. According to parts list HYL 3698/1, AUF 201 was fitted from inception of the Australian S. However, the later publication PUB1056M suggests that up to car 811 used AUF 204 and AUF 214 from 811 onwards. All three pumps are all essentially the same, but with minor differences in the diaphragms, coil housings and sundry parts. This general pump style is virtually the same as present-day replacement items. Major differences with current pumps are the manufactures label, plastic instead of cast alloy inlet and outlet fittings and an ever changing array of points end-covers. Earlier styles of cover are available, but many do not accommodate the diode or condenser sometimes fitted to extend points life. Condensers are suitable for either polarity applications, but diodes can only be fitted to negative earth cars.
The significant difference between these designs and the even earlier pump AUA83 is separate, swivelling, inlet and outlets retained by two screws and a locking ring. This was most probably intended to widen the pumps range of applications for other vehicles and environments. All styles retain 5/16Ó diameter fittings. This is despite the main fuel pipe for the Mini, running the length of the floor pan, being 1/4Ó in diameter.
BMC’s means of overcoming this step in size were dubious to say the least. Some body (fuel) pipes are flared at the pump end and abut the tapered outlet of the pump. The length of Smiths Petroflex used (21A 208), does not appear to be of special construction to compensate for the size difference.
All fuel pumps fitted to the Australian Mk 1 ‘S’ used a breather tube and nipple which vented into the cabin. For unknown reasons, these parts were deleted from most of the Australian parts books. As the remainder of Australian production used a mechanical fuel pump by time the ‘S’ was introduced, the vent hole became unique to the ‘S’ body. Locally made early 850s often provide a valuable source for these obscure parts.
More next month.
MARK PAGET.
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