Tests and Reports

In August 1936, "The Motor" presents the Rover range for the 1937 model year. The article describes all available models of the series now known as "P2".

ROVER - Two New Cars and Remodelled Bodies

"The Motor", August 18, 1936

Each succeeding year the Rover programme announcement is eagerly awaited by the increasingly large following of motorists who confine their purchases to high-grade cars of moderate power and price. The range of models for the 1937 season is of particular interest because two new cars are introduced, and the coachwork carried by the other chassis has been very largely remodelled. Those distinctive saloons and sports saloons display a number of refinements.
It has, of course, been something of an open secret that a more powerful car than the Fourteen has been on the stocks for some considerable time; the 16 h.p. and 20 h.p. models which we are about to describe are both the result of intensive experimental work extending over a long period.
The illustrations show that so far as coachwork is concerned the new models bear a family resemblance to the previous range of coachwork. The wheelbase and track of the Sixteen and Speed Twenty are the same as the equivalent dimensions for the Fourteen, but there the similarity ends because an entirely new chassis frame, power unit, steering layout and so forth are included in the specification of both these more powerful cars. Bore and stroke dimensions are 67.5 mm and 100 mm (2.147 c.c.) for the Sixteen, and 73 mm and 100 mm (2,512 c.c.) for the Speed Twenty.

Light Yet Rigid Frame

The frame is of extremely robust construction and has box-sectioned members throughout. It is not heavy because, by using deep pressings (actually the depth of the main channels is no less than 6 1/2 ins.) and by welding enclosing plates on to the flanges, such a stiff structure is produced that relatively thin material can be used. The side channels are straight pressings, which pass over the front axle and under the rear axle. There are no fewer than seven box-section cross-members in addition to angularly placed ties at the front. An important point is that the shock-absorber brackets are all built into the main structure.
Light but well-ribbed pressings are attached to the outer flanges of the main channels to carry the body sills, running boards, etc., and the support so afforded is certain to have a beneficial effect upon important items such as the fit of the door fixtures, hinges and so forth.
Semi-elliptic springs are used fore and aft, those at the rear being outrigged from the main frame to give the widest possible springbase for stability on corners. A Burman-Douglas steering gearbox is mounted inside the front cross-bracing member and a transverse drag link is employed in order to keep the geometry of the mechanism as nearly perfect as possible. As the column is well raked the position of the wheel is particularly comfortable.
Although the Sixteen and the Speed Twenty engines differ in size they are almost identical in specification, so that one description will suffice for the two units. As in the existing models in the Rover range, a unit construction is employed, the housing which contains the clutch and gearbox being mounted on a flange formed at the rear end of the cylinder-crankcase casting. This casting is very substantial, being deep and well braced internally, to carry the four-bearing crankshaft.
Another practical feature which will be appreciated by both owners and service mechanics is that the sump flange, and, indeed, all the major flanges on the engine, are wide and the securing bolts closely spaced so that really effective oil-tight joints can readily be made. The complete unit is mounted in the frame at three points, all of which have rubber inserts. At the front a pair of brackets is bolted to a facing strip on the engine body, rubber washers being placed above and below the arm extensions. A very large rubber trunnion bearing is to be found at the rear end, where a circular housing encloses a machined portion of the free-wheel casing behind the gearbox.

A detachable cylinder head carries vertically disposed overhead valves, which are operated, in the usual Rover fashion, by push rods and rockers from a camshaft contained in the crankcase. At the forward end of the head is an expeller water pump, and the inlet and exhaust manifolds are built on to the off side of the head. The layout of the manifolds is more than ordinarily interesting. Three siamezed ports communicating with the inlet valves are covered by branch pipes, which merge into a common chamber of roughly circular shape formed beneath the carburetter stub. To the under side of this chamber is attached the exhaust manifold, a gas-tight joint being made by means of a plain copper washer. In this way a high conductivity factor is attained so that at all speeds an effective hot-spot is afforded.
At the forward end of the unit will be seen an external friction-type crankshaft vibration damper. In front of this a pulley provides the drive to the water-pump fan spindle and to a ventilated dynamo housed in a cradle on the near side of the engine body.
For the rest the specification of the existing 14 h.p. model applies to the new types - a single dry-plate clutch and a four-speed gearbox with helical pinions for the constant rnesh, second and third-gear trains transmitting the drive through a free wheel to the usual needle-roller propeller shaft and spiral-bevel rear axle.
The forward gear ratios of the Sixteen are 4.7, 7.l4, l0.62 and 18.99 to 1. Naturally, the Speed model ratios are somewhat higher, the axle ratio in this case being 4.5 to l. Other chassis features include Girling balanced mechanical brakes all round, with a linkage to allow the hand brake to operate independently on the rear wheels only, and wire wheels with Magna-type hubs equipped with 5.50-in section tyres on 17-in rims.

The 10 h.p., 12 h.p. and 14 h.p.

In the main the mechanical components of the Ten, Twelve and Fourteen chassis are not materially altered. The Ten and Twelve models have four-cylinder units with capacities of 1,389 c.c. and 1.495 c.c. respectively, whilst the capacity of the six-cylinder Fourteen engine is 1.577 c.c., as formerly. All the engines have overhead valves, a crankshaft bearing between each pair of throws, a full-pressure oiling system and a ventilated dynamo driven by belt. The transmission on these models is on exactly the same lines as that of the new chassis already described. A new inbuilt Stevenson jacking system is now fitted to the 12 h.p., 14 h.p., 16 h.p. and 20 h.p. cars.
New features include l2-in. diameter cast-iron brake drums for all models, the design of the drums being such that enormous rigidity is afforded; a deep flange causes water to be readily thrown away from the friction surfaces. General equipment includes Avon tyres, Triplex glass and British Jaeger instruments.

Coachwork Features

In dealing with the bodywork we will commence with the 10 h.p. model. This saloon has been altered in design and in the contour of the roof and rear panel to enhance the appearance. The front doors now hinge on the central pillars and the bottom corners are rounded to give easy access to the seats. Another improvement in appearance is connected with the front wings, which are lower at their forward end, whílst the side valances are deeper than in the past; a ventilating windscreen with a centrally operated handle is also to be found in the specification.
The bodywork of all models other than the Ten has been standardized in type, although not necessarily in dimensions. The rear quarters of both the sports saloon and the normal six-light saloon follow something upon the lines of the 1936 model sports saloon, a built-in and capacious luggage container being attractively moulded into the rear panel.
The illustrations showing the various body types give a clear indication of the lines of the new cars. The frontal appearance has been altered by mounting the front wings higher up the side of the radiator and continuing them in a curve which terminates more or less abruptly at the running board. The wings themselves are larger than those of the 1936 type and they run to a lower point at their front edges, whilst a wide inside valance is provided. An interesting feature of the mudguard assembly is that the radiator block, radiator shell, the two front wings and their supports are built up separately to form a unit.
In all models the seats are upholstered in soft Vaumol hide, and the workmanship and general refinement are of the same high quality which has gained for Rover cars so many awards in coachwork competitions. A wide range of colour schemes is available. Triplex glass is employed for windows and windscreen, and dual screen wipers are standardized.

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In August 1938, "The Motor" presents the Rover range for the 1939 model year. The article describes all alterations to the models of the "P2" series.

Cars 1939 - The New Season’s Rovers

Detail Modifications to 10, 12, 16 and 20 h.p. models.
An Entirely New 14 h.p. Engine.
New Drop-head Coupé Available On All 6-cylinder Chassis

"The Motor", August 23, 1938

The Rover programme for 1939 will be of particular interest to a large number of motorists, for this company is fortunate in having established a clientele of its own, and one which is, rnoreover, continually extending as so many motorists realize the wisdom of buying a quality class of car.
For 1939 the Rover company are continuing their existing range of models, which consists of two four-cylinder cars rated at 10 h.p. and 12 h.p., and three six-cylinder types rated at 14 h.p., 16 h.p. and 20 h.p. There have been certain engineering changes which are general on all of these types. These all contribute to economy, performance and ease of driving.
Taking the power units first, these have modified cylinder heads compared to last year's types, giving high-velocity water cooling to the hot spots in the cylinder head. Whereas on previous models the pump drew water through the head and passed it into the radiator, it now delivers it at some considerable pressure into the cylinder block. This forms a distribution manifold from which the water flows through jets on to the exhaust-port seats, as shown in a sketch. In addition, a thermostat is included so that normal running temperature is reached very quickly after starting, and provision is also made for easy fitting of car-heating equipment if this should be required.
On the four-cylinder engines an interesting new manifold is used, with entirely separate passages to the two inner und two outer cylinders. This has resulted in much improved distribution and has enabled the hot-spot area to be cut down, features which, taken in conjunction with the improved head cooling, have enabled the compression to be raised approximately half a ratio. Thus there is not only improved power output but greater economy.
So far as six-cylinder engines are concerned, the 16 h.p. and 20 h.p. are not greatly altered except in respect of the new head design, but the 14 h.p. type is entirely new. It now has a capacity of 1,901 c.c. as against the previous engine's 1,577 c.c. and is externally very similar to the other and larger six-cylinder units. It has in common with them, for instance, a fully counter-balanced four-bearing crankshaft, downdraught carburetter and accessible layout of such components as the distributor and dynamo.
From the owner's vıewpoint an even more interesting feature of the new Rover range is the entirely new transmission. It will be remembered that last year the Rover company introduced a clutch which gave exceptionally sweet take-up having a floating withdrawal member which ensured that the plate always came up dead square against the flywheel. This was used in cunjunction with a free wheel in the transmission, a component which has been standard on Rover cars for many years. With it, gear changing is, of course, a simple matter of moving the lever to the required position with the throtlle shut and then applying the power as required. It is recognized, however, that some owners prefer a fixed drive, in which case double declutching has been necessary to effect a quiet gear shift. To overcome even this minor disadvantage a new gearbox has now been developed giving synchromesh between third and top, with large (3 1/2 ins. diameter) engaging cones. Thus, under all conditions the mechanical skill needed in driving has been reduced to a minimum.

The qualities of steering and control have also been greatly improved on the six-cylinder types by the use of anti-roll stabilizers at both front and rear of the car. These take the form of torsion bars running across the frame, connected to the axle by parallel arms and serve the dual purpose of reducing roll and improving the cornering power of the car. Those two terms are by no means synonymous and very careful research has been carried out on both aspects of the question. A further refinement is the use on all models of the new Luvax-type shock absorbers.
The Girling brakes respond to very light pedal pressure and have drums heavily flanged to give good rigidity. They are carefully designed to prevent entrance of water.

Coachwork Details

Turning now to the coachwork of the cars, there are several entirely new types. One of these is the new 10 h.p. saloon which now has a large built-in luggage compartment with a concealed spare wheel at the back, thus bringing it into line with the other types and substanially increasing its utility. The coupe on the 10 h.p. and the saloons and sports saloons on the 12 h.p., 14 h.p., 16 h.p., and 20 h.p. cars are virtually unchanged, with the exception of small detail improvements. One of these is the provision which has been made to enable the windscreen wipers to come across the screen when this is slightly open. The design enables the car to be run in this condition through rain without any wet entering the body, as there is a baffle fitted at the base of the screen frame.
An automatic reversing light is now fıtted and in addition the pass-light system has been adopted at the front, this coming into operation when the dip switch is used for the main head lamps. A further very welcome change is the availability ol drop-head coupés on the six-cylinder types. These are of the well-known Tickford type built by Messrs. Salmons, and are particularly fine examples of this attractive form of coachwork. They can be opened to either the coupé-de-ville position or have the head fully loaded, and their lines have been carefully chosen to blend with radiator and mudguards.
Duo colours are not available on the new cars, the standard colours now being dark blue, green, grey, maroon and black.
Summing up, we can say that the Rover policy of steady improvements in design of a well-established range of cars is one which will meet with approval by a large number of potential purchasers, and we feel sure that they will not be disappointed by the performance or the construction of the new types we have just described.

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In an article of several pages in August 1939, "The Motor" presents the ROVER models for 1940. It is certainly interesting to learn about the planned changes - it was not foreseeable that the start of the war would bring production to a standstill.

1940 Cars - The Rover Range

"The Motor", August 15, 1939

To say that the sales of Rover cars for the 1938-9 season have broken all previous sales records may savour of wearisome reiteration. This remark has been true of several companies whose products we have described in recent weeks, yet it is interesting to note that in each case the cars concerned have been high-quality models selling at more than average prices. This would seem to prove that owners are willing to pay a premium on purchase price when they get a real return, and as in quality Rover products have been pre-eminent for many years it is unnecessary to enlarge on this aspect of their construction.
The cars for l940 bear a general resemblance to those previously made and the range consists of four-cylinder models of 10 h.p. and 12 h.p. rating, and six-cylinder cars rated at 14 h.p., 16 h.p. and 20 h.p. On the first-named there is a choice of saloon or coupé bodywork; on the others, sports or sports saloons, whilst all the six-cylinder chassis can be obtained with a drophead coupé body by Messrs. Salmons.
The colours, finishes and prices for all models also remain as before, and this policy of the company is of considerable assistance to the owner in maintaining the second-hand value of his car and thereby appreciably reducing the largest single item in car ownership, viz., depreciation. Despite the similarity in general appearance of the cars, a considerable number of improvements has been wrought in the bodywork. In every model except the Ten an increase in the rear track from 4 ft. 4 ins. to 4 ft. 6 ins. has made it possible to widen the rear seat, giving comfortable seating for three average passengers. The actual dimensions across the front of the seat is 50 ins., and between the arm rests 45 ins. Moreover, the cushions on these cars now have sponge rubber top pads over spring cases, which have been found to give increased comfort as compared with previous constructions.
Another easily noticeable alteration is the new facia panel, which is illustrated in our photogravure pages*. This has been tidied up considerably, the styling of the instruments is now uniform and they are symmetrically laid out over the panel. All models now have a water temperature gauge which is coupled with an oil pressure gauge, and also an electric clock. Another electric device is the reserve petrol tap which is operated from a switch on the facia. The tanks have capacities of 10 gallons for the Ten, 10 1/2 gallons for the Twelve and 11 3/4 gallons for the six-cylinder models. ln addition to the tap there is a level gauge electrically operated from the facia panel and this is combined with another showing the level in the sump.
The treatment of the body adjacent to the facia is improved, there now being a wooden garnish rail above the panel in place of the fabric cover previously employed. The windscreen can be opened through a wide angle and it is interesting to note that in addition special provision is made for opening it slightly to provide forced ventilation. Moreover, in recognition of the necessity of this under warm, rainy conditions, a baffle is fitted so that the screen can be placed slightly ajar without rain being blown into the body and with the screen wipers operating normally.
Continuing with our summary of outward and visible changes, on all the sports saloons, the 10 h.p. coupé and drop-head coupés Lucas twin wind-tone horns are supplied, one mounted on each dumb-iron with a chromium-plated crossbar carrying a Lucas pass-light in the centre. On all the models a pass-light is provided and comes into operation when the dip switch extinguishes the head lamps.
On the 10 h.p. saloon ventilating louvres are now fitted to the doors and all the intenor woodwork is walnut, including the window frames. Triangulated ventilating panels have also been added to the drop-head coupés. These bodies have modified tops, lowered seats and many other detailed refinements, placing them in the front rank of convertible coachwork available on British chassis. Finally Rubery Owen easy-fit wheels are standardized, carrying the new type of Silent Tread Avon tyres, the 10 h.p. having 17 by 4.75 in., the 12 h.p. 17 by 5.25 in. and the six-cylinder models 17 by 5.5 in. Wire wheels can be supplied at an extra cost.

Turning now to the mechanical aspects, it may be remembered that last year the four-cylinder engines were equipped with improved manifolds in which there was a completely separate intake pipe for pairs of two cylinders. This gives the best possible distribution and is of considerable assistance in getting pulling power at low speeds and good fuel consumption. The same principle has now been applied to the six-cylinder models except that in this instance not only double manifolds but a double carburetter is used. This Zenith instrument has a single float chamber supplying fluid to twin jets and choke tubes and is mounted in the centre of the engine. Extending right and left are two entirely separate induction systems which have been designed with great care to provide even distribution of the mixture to each cylinder. The result of this change, coupled with a modified hot-spot arrangement, has been to increase the power of the engines at the bottom end by about 20 per cent. Put another way, the top gear acceleration and hill-climbing of the 14 h.p. model is now equal to last year's 16 h.p., with the larger cars improved pro rata. Fuel consumption has not been impaired by this gain in power, nor quietness of running, a very large intake silencer having been provided.
Another interesting point in the top part of the engine is the system of water circulation, which has proved highly successful last year and is continued unchanged. All the water from the pump is forced into the cylinder block where it is maintained at a substantial pressure. Jets are drilled between the block and head to feed water at high velocity over the sparking plug bosses and exhaust ports, this not only giving a long life to these components but also enabling the highest possible compression ratio to be employed.
The engines have light alloy pistons, counter-balanced crankshafts, and all have overhead valves operated by push-rods. Power is transmitted through a single plate clutch and this is a patented Rover feature with a spherical withdrawal rnechanism which ensures the floating plate engaging quite squarely and thus giving a smooth take up. The engine being rubber mounted and having a considerable degree of flexibility in the case of the four-cylinder types, the clutch is operated by a cable which is enclosed at the bottom end and lubricated. The Free Wheel retained with the exception of one Continental car, Rovers are the only constructors using a freewheel device, but this has proved very popular and has definite technical merit. It gives the easiest possible gear changing and offers a useful reduction in fuel consumption. It can he locked out of use if not needed and in this circumstance the very positive synchromesh engagement provided between top and third gears would be welcomed. The design of the gear teeth has been altered slightly in the current models, but apart from this the transmission of the cars remains unchanged.
The rear axles, however, now have an improvement which will be found extremely useful to any unfortunate who has to undertake a wheel change.

Easier Wheel Changing

Fitting wheels held on by studs is quite difficult because in addition to supporting the weight of the wheel and tyre at an awkward angle, one has to engage the studs with the holes in the wheel. Most women and numbers of elderly people may find this operation one that really taxes their physical powers. On the Rover the job is made very much easier by providing a support for the wheel. This consists of an extension sleeve, as shown in an illustration. All that is necessary is to push the wheel on to the sleeve, run it up against the studs, turn until they match the holes, then holt the wheel home.

Semi-ellíptíc Springing

Conventional axles are fitted to both front and back of the car located by semi-elliptic springs. Luvax piston-type hydraulic shock absorbers are used, and with the exception of the 10 h.p. car, anti-roll stabilizers are used for both rear and front axles. An improvement relating to the former is a spring-loaded drag link. Steering designers have to avoid the Scylla of springy and indefinite operation, and the Charybdis of a harsh steering which transmits road shock back to the driver. The Rover Co. have fitted a very direct steering and provided pre-determined shock absorption by using a new drag link.
Girling brakes are fitted as before and the drums are not only deeply ribbed to give great rigidity, but also are sealed to prevent water getting on to the brake linings which would impair general efficiency. lt will be seen that the policy of the Rover Co. has been to improve already successful models and not to introduce radical alterations, although the improved manifolding provided on the six-cylinder types is certainly a substantial change. We feel that this policy is one which will command itself to large numbers of people who, being Rover owners, make a practice of replacing their existing cars with another of the same make. On merit alone, the cars must make a considerable appeal to anyone who desires a quality car at a reasonable figure.