Car of the year logo (2,32kB) The Rover SD1 "3500"
European Car of the Year !!!

Car of the year logo (2,32kB)


A ir-Blending Heater.
In line with other Leyland models, the new Rover uses the fresh air heating and ventilation unit of corporate design which has extremely good volumetric capacity and efficiency.
A three-speed blower fan gives large volume air flow even at low speed and a recirculation mode is provided to obtain quicker warm up, and avoid the intrusion of traffic fumes during town use. Air is ducted to facia vents for the driver and front seat passenger and a large central vent for the rear seat passengers.

For heating the rear compartment, ducts direct hot air via two transmission tunnel vents to the rear footwells, and to obtain thruflow ventilation, extractor vents are situated in the rear door. The passage of air through the car contributes to the demisting of the large rear window, but for rapid demisting and deicing a heated rear window is fitted.

Side window demisting of the front passenger doors is achieved by ducting of air from the heater air chamber via the facia ends into the doors and out of vents onto the glass at the top of the door trim pad, proving Rover's concern for safety at all times.
As an added safety feature, tinted glass is fitted all round to cut down on glare and eyestrain.

F use Box.
In order to facilitate the checking or changing of fuses, the fuse box is located on the right hand side of the driver's instrument binnacle. The cover is removed by turning a fasten stud in the centre and a list of the fuses is attached to the inside of the cover. Benefit - a quick and accurate check.

B ulb Failure Warning Light.
As another safety precaution the Rover 3500 is equipped with a bulb failure warning light, located on the instrument binnacle. This gives visual warning of a bulb failure in any of the side / tail, brake or number plate lights.
If there is a total failure of the cars lighting system a 'get you home' standby is available. The rear left hand side trim pad is removed to reveal a multipin plug / socket. The plug can be disengaged, a small lug removed, and the plug replaced the opposite way around. This is only a temporary measure and the car should be checked as soon as possible.

E lectric Window Operation.
The new Rover is fitted with electrically operated side windows, activated by individual switches on the centre console to the rear of the gear lever, and alongside the manual choke lever.
The rear door armrests also include personal switches for each individual rear window and in the event of the rear seat being occupied by children there is an isolator switch on the instrument binnacle to disconnect the operation of these rear switches for safety and security.

In the event of an operating failure of any window, caused by an obstruction such as ice, the circuit is equipped with a reset button behind the passenger glovebox which can be used in an emergency to close or open a window until the circuit can be checked, or the obstruction removed.

E ngine And Transmission.
After many years experience with the Rover 3.5 litre V8 engine, Rover's engine design team have developed the unit still further for use in the new Rover 3500. The engine has redesigned cylinder heads, inlet and exhaust manifolds, valve gear, improved oil and water pumps, so that it develops an extra 9 kw at 250 higher rpm, giving 115 kw at 5,250 rpm. As a result of these changes maximum torque is reduced from 28.2 kg mat 2,700 to 27.34 kg mat 2, 500 rpm ; but the top rev. range has been increased from 5,200 to 6,000 rpm by altering the valves in the hydraulic tappets and fitting increased size inlet / exhaust valves, and new single valve springs.

As before the engine is charged through twin SU HIF 6 carburettors but the intake has been modified to incorporate the Leyland Award winning air temperature control system. This consists of a bimetal strip which when cold closes a flap valve and air is drawn from the vicinity of the exhaust manifold to facilitate quick engine warm up. When the engine temperature rises the bimetal strip expands and opens the flap valve allowing cool air to be drawn from the front of the engine for normal running. Quick engine warm up means less use of the choke, less engine wear and better fuel economy.
Changes to the exhausts manifolds in particular have improved engine breathing, and with dual outlets for each bank phased as follows
Left hand 1+5, 3+7
Right hand 2+4, 6+8
the extractor effect improves 'top end' torque, and accounts for the majority of the increase in engine power.

E lectronic Ignition.
This system offers considerable benefits to multi-cylinder engines and in particular the Rover V8 unit. The single contact breaker system would have been unreliable on the engine with its increased rev. range up to 6,000 rpm, so Rover designers chose the Lucas Opus electronic ignition system using a proximity switch make and break and with the amplifier built into the distributor body.

Electronic ignition reduces the need for constant engine tuning and therefore ensures that the engine is working at maximum efficiency thus giving better overall performance and economy.
In this system there are basically no moving parts, except for the central timing rotor and therefore the timing is electronically controlled and remains within precise limits. Electronic ignition gives a stronger higher voltage and consistent spark at the plug, which in turn reduces plug fouling due to poor ignition at low speeds and allows the engine to develop maximum power up to the 6,000 rpm maximum.

Thus this system gives benefits to the customer as follows:
- accurate engine timing
- good fuel economy
- reduced plug fouling
- higher engine revs
- lower servicing costs
- better reliability

D iagnostic Engine Tuning.
To meet today's stringent anti-pollution regulations, accurate ignition and engine timing are essential for efficient working and British Leyland have specially developed this system for Service engineers to use in diagnosing and correcting ignition faults.

Using a magnetic transducer by the front crankshaft damper to sense the crankshaft position, the diagnostic equipment, which plugs into a socket on the front of the engine (as shown), provides rapid checking of timing, dwell angle, low tension circuit output and high tension pulse quality. This ensures that the engine is kept precisely in tune, runs at its most economical and gives reliable cold starting.

I mproved Oil Pump.
During engine development modifications have been made to the oil pump with the drive gear strengthened and more rigidly sup-ported, while the sump has improved baffles to cope with the higher acceleration forces which the new car generates. Oil pump capacity is higher to avoid marginal lubrication at idle speeds. While the engine front cover was being modified to accommodate these changes, the crankshaft end seal was changed to reduce air leakage into the positive crankcase ventilation system. A safety item built into the oil pump is the low oil pressure cut-out switch. This is wired up through the oil pressure warning light, so that when the low oil pressure warning light is illuminated because of a fault there is an immediate cut-out of the fuel pump. This makes it impossible to drive the car with insufficient oil-pressure, and in the event of an accident immediately cuts off the fuel to reduce the fire risk.
This switch does not operate when the ignition is switched on preparatory to starting the car.

A utomatic Gearbox.
The standard optional fit automatic gearbox for the new Rover 3500 is the Borg Warner Model 65, three-speed unit which is an improved version of the model 35 offering smoother gear change quality, and a more robust specification. A 279 mm diameter torque converter is fitted and gear selection is by means of a centre-console mounted lever with a comfortable, stylish safety design grip. Final drive ratio is 38.5 km/h per 1,000 rpm.

M anual Gearbox.
One of the new components fitted in the Rover 3500 is the LT 77, corporate design, five-speed manual gearbox - 77 mm being the designated distance between the main and layshafts centres. The gearbox uses a single rail selector mechanism, with baulk ring synchromesh on all five forward speeds, and a remote control gear selector lever falling easily to the driver's hand, and rubber mounted to restrict engine vibrations.

The positioning of the gears in the selector quadrant is for the first four forward gears to be in the usual H pattern and fifth away from the driver and forward. Reverse is towards the driver and forward, and both fifth and reverse gears are spring loaded in order to minimise incorrect gear selection.

The gearbox casing is in cast iron for added strength, with the bell housing and gearbox tailpiece in aluminium.
Taper roller bearings are used to contain end thrust in the gearbox and needle roller bearings are used for all gears on the mainshaft except fifth. As on the previous Rover 3500, the gearbox has its own integral oil pump to assist lubrication by feeding oil direct to the mainshaft bleed holes and spigot bearing.
The gear ratios have been carefully selected with fifth gear being in effect an overdrive ratio and giving a very high final drive ratio of 46.4 km/h per 1,000 rpm. This combined, with the body shape and V8 engine, gives the new Rover 3500 a high cruising speed at low engine revolutions, less engine wear, increased fuel economy, and greater driver comfort.

T ransmission.
The propshaft is divided into two parts, a relatively short open section from the gearbox using plunging constant velocity joints at both ends for smooth running, leading to another short shaft enclosed within the torque tube attached to the rear axle. This torque tube, which is mounted via rubber bushes at its forward end, reacts to drive and braking forces in such a way as to oppose any tendency for the car to 'squat' or 'rise' at the rear end. It also forms part of the rear suspension geometry.

S uspension And Brakes.
Front suspension on the new Rover is a complete reversal of the intricate system as used on the 2000 model, and Rover designers have achieved a high standard of success with Macpherson strut suspension which gives extremely good ride and handling qualities while using a relatively simple layout. Experience with Macpherson strut front suspension on the Triumph 2000 was drawn on for a similar layout on the new Rover. An offset coil spring location is used to balance the binding effect of the stub axle moment thus giving a stiction free suspension movement, while ball bearing top swivel mountings give similarly smooth steering rotation. The bottom of each strut is located transversely by a single link, and in a fore and aft direction by the anti-roll bar.

The result of this system, while reducing the space required and the material economies, is to minimise roll-induced camber variations, and lower the roll centre as roll increases. Along with the anti-roll bar, Macpherson strut suspension offers many advantages over previous Rover systems without sacrificing road holding and handling characteristics.

At the rear a live axle is located laterally by Watts linkages pivoting on the differential housing, and by two radius arms at the outer ends of the axle to counteract longitudinal movements of the wheels. Drive torque is controlled by an extension of the differential housing nose piece casing and this torque tube is attached to a rubber mounted cross member via a small link bracket. Because the torque tube is offset laterally owing to the hypoid differential layout, the pivot point of the link bracket is located on the centre line of the car, as is that of the Watts linkage. The car is supported on relatively soft coil springs which have long vertical travel, for good ride comfort. Working in co-operation with the coil springs are two Boge Nivomat self-energising levelling damper struts, mounted forward of the axle at the ends of the axle tube to give optimum damping control in bounce and roll.

Unlike other self-levelling suspension systems which are pressure fed via a pump from the engine, the Boge Nivomat units make use of the spring energy which they are employed to dissipate to maintain the nominal rear ride height whatever loading, up to the maximum, is employed.

The continuous pumping action when the car is in motion either acts as a damper when there is little or no load, or raises the car rear by transferring fluid under pressure to an upper chamber until the correct ride height is achieved and maintained, when rear passengers or a load are carried.
Self levelling rear suspension permits the use of soft constant rate springs for excellent ride qualities without the normal penalties of changes in attitudes and handling.
As an added benefit, in Service the complete rear axle assembly and suspension can be disconnected and removed rearwards from the car for ease of maintenance and reduced service costs.

B raking System.
To compensate for the added performance of the new Rover, power assisted, dual line hydraulic brakes are used, with disc brakes fitted at the front and self adjusting drums at the rear. The braking circuit is split with separate actuation of the front discs so that in the event of brake failure both front and one rear braking are retained.
Failure in either circuit is shown by a dashboard warning light connected to a pressure differential warning actuator switch. The warning light shines brightly in the event of brake failure, and normally to indicate low brake fluid level and that the handbrake is in the 'on' or park condition.

A rear circuit pressure limiting valve is fitted to minimise rear wheel locking, but this is automatically isolated in the event of a brake circuit failure, to maximise the remaining braking effort.
The direct acting vacuum servo provides balanced assistance to the brakes, and benefits all drivers in order to maximise on the safe control of the car.

S teering.
Rack and pinion steering is used for the first time by Rover on the new 3500. It is a new design by Burman, power-assisted, and mounted on the front of the suspension cross member. The steering column incorporates a collapsible safety system as well as being adjustable both vertically and axially. High gearing of the rack takes advantage of the power-assistance requiring only 2.7 turns of the wheel from lock to lock, and giving a turning circle between kerbs of only 10.4 metres.

The result is effortless, sensitive and quick steering, and, combined -with the overall body / suspension design provides the driver of the new Rover 3500 with a fast, safe, controllable car to compare well with other cars costing double the price which have more sophisti-cated suspensions.

Thanks to: Shirley Rimmer.

Heater Unit

Side Window Demisting

Blub Failure Warning Light

Air Control System

Opus Ignition

Diagnostic Plug

Improved Oil Pump

5 Speed Gearbox

Macpherson Strut

The Front and Rear Brakes

Failure Circuit

1977 SD1 Car of the year 9,6kB)
Part I
Part II

© RWP mach. 2006