Expensi and Proud of It, Too!
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DESPITE the increasing number of low-priced 5-tonners emanating from factories ink, various parts of the world, many of which are of surprisingly good standard, there is a continued demand for high-quality vehicles of this capacity which can be expected to give a much longer trouble-free life, for which operators are prepared to pay a higher initial cost.
Sweden is not e.`t1 for high-quality products and its people appreciate good quality when they see it. This, coupled with the natural preference for an indigenous product, rather than an imported article, explains the success with which the Volvo L 430 series of 5tonners has been placed on the market.
I conducted the first road test of one of these vehicles during a recent visit to Sweden. The occasion was doubly unusual, because this is one of the few vehicles of its class with a V8 petrol engine to be manufactured outside the U.S.A. Road performance was naturally a little more exhilarating than could be expected from a comparable British vehicle ' with a six-cyfindered unit, whilst the fuel economy was tolally unexpected. One of the fuelconsumption tests made w a s conducted under
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drivers on the Continent and in Scandinavia, but is somewhat different from that of most British drivers, who, unless really in a hurry, prefer to restrict their gear-changing to third and top ratio. •My statement that the gearbox must be used to the maximum effect is not meant, however, to imply that the top-gear performance is poor: indeed, it is above average for this class of vehicle and would be more than acceptable by British standards.
The Volvo forward-control series of V8 petrol-engined chassis consists of two basic models. One of them is the L 420, which is intended primarily for short-distance delivery work with payloads up to 3 tons.
It has much in common with the heavier L 430, which formed the subject of this test, including a similar engine and gearbox, but the axles and frame are lighter and the recommended gross laden weights are 4 tons cwt. when single rear wheels are fitted and 51 tons when twin rear wheels are specified. The L 430 can operate at a gross laden weight of 71 tons with a single-speed axle or 8 tons when equipped with a twospeed axle and 8.25-20-in. tyres; 7.50-20-in, equipment is standard.
Technically, the 16-litre power unit k the most interesting feature of the design. It was originally developed for a private car which never went into production and has " oversquare " cylinder dimensions, the short stroke permitting crankshaft speeds of over 4,000 r.p.m.
The overhead valves are push-rod operated from a chain-driven camshaft above the crankshaft. In addition to endowing the unit with a high power output without loss of economy, the valve arrangement simplifies maintenance in situ, compared with some of the earlier American side-valve designs with which people in Britain may be familiar.
As the compression ratio is relatively high at 7.6 to 1, premium-grade fuel must be used. A Carter WGD 23745 twin-choke carburetter is employed and the induction manifold is completely water-jacketed to ensure an even mixture temperature through out the length of each bank of cylinders: The carburetter is fed by an A.C. diaphragm-type pump mounted immediately ahead of it.
A Bosch distributor is mounted vertically above and driven off the camshaft through skew gearing. When running on 93-octane petrol, the static setting for the contact-breaker points is 6° before top dead centre, the automatic advance mechanism bringing the ignition setting to between 20° and 22° before top dead centre at 1,500 r.p.m.
Power passes through an 11-in.
diameter single-dry-plate clutch to a Volvo K 4 four-speed synchromesh
gearbox on which there is provision for a power take-off. The lever is mounted directly at the top of the gearbox and is curved so that the knob lies approximately over the engine
centre line, close to the steering-wheel rim.
Behind the gearbox there is a band transmission brake operated by the hand lever. The drum on which this brake acts has an external diameter of 9 in., whilst the brake band is 21 in. wide and is lined with .-in.-thick friction material.
From the gearbox the drive passes through a two-piece propeller shaft to the rear axle, which on the standard chassis is a hypoid-bevel single-speed unit with a standard ratio of 6.83 to 1 and an alternative reduction of 6.33 to 1. An American-made Eaton 13600 two-speed axle with ratios of 6.33 and 8.81 to 1, and electrical shift mechanism, can be supplied. This axle is not available in Britain, but is similar to the British-made 1350 spiralbevel unit except that it has hypoidbevel gears. Its load rating is 7 tons 3 cwt.
Semi-elliptic springs are aided at the rear by helper leaves and at the front by inclined telescopic dampers. The L 430 chassis is available only with left-band drive. The Z.F.-Gemmer GD48 cam-and-roller steering gear has a ratio of 20.5 to 1, giving approximately five turns from lock to lock.
American-made Lockheed hydraulic brakes, with two-leading-shoe units at both axles, are employed. A Lockheed Hydrovac vacuum servo is installed.
The chassis frame is built up of A-in.-thick pressings, the side members having a maximum depth of 81 in., with flanges 2+ in. wide. There are three alligator-jawed crossmembers and two channel-section cross-members, and riveting is employed for the assembly with the exception of those members adjacent to the engine-gearbox unit, which are bolted to simplify removal. The frame top flange is level rearward from the centre line of the front axle.
The Volvo-designed cab is of allsteel construction throughout and its general appearance is pleasing. The steps are ahead of the front wheels and the main floor line is reasonably low. Access would, however, be made even easier if the forwardhinged doors were to open through a wider arc.
Good all-round vision has been assured by the use of a wide curved one-piece windscreen, two deep fullwidth rear windows and generous door glazing. The opening provided by the two sliding window panels in each door is just sufficient to enable the driver to put his head through it.
Heating and demisting equipment is standard and the windscreen is demisted by no fewer than 14 equally spaced nozzles. Both seats are adjustable for height and reach by moving the seat base relative to fixed pegs. The squab angle can also be adjusted.
Cab fittings include a neat instrument cowl immediately ahead of the steering column; a small locker in the centre of the facia panel, immediately above which is an ashtray; and a grab handle on the passenger side. A small door on each side of the locker gives access to the electrical fuses.
The chassis offered for test was the medium-wheelbase version, the two other models having wheelbases of 9 ft. 10 in. and 12 ft. 6 in. It was equipped with 7.50-20-in. (10-ply) tyres, instead of the 8.25-20 tyres normally recommended for the maximum running weight. A temporary drop-sided body had been fitted and iron weights totalling 5 ton 1 cwt. formed the payload.
Thus the Volvo was tested at a gross weight of 8 tons 41 cwt. The front-axle loading of 3 tons 61 cwt. was somewhat high and was later to influence the braking figures.
Acceleration and brake tests were conducted along the old main road leading north from Stockholm, which runs parallel to the new motorway. All the acceleration figures were obtained with the' rear axle in low " ratio and for the standing-start tests all four ratios of the main gearbox were employed. Consistent results were obtained in each direction and the figures emphasized the liveliness of. the design.
When making the braking tests all wheels locked from each speed and the figures obtained were somewhat disappointing. They would, I feel sure, have been better had there been a higher proportion of the load over the rear wheels. The test weights were, however, evenly distributed throughout the length of the body and the results were what could be expected in normal service.
The Volvo engineers who were with rue considered it unwise to attempt an emergency stop with the hand brake, because it is so powerful that it might have damaged the gearbox. This is unfortunate, because a transmission brake can be valuable in an emergency, but it is of little use if. it cannot be applied without other damage resulting.
Two sets of fuel-consumption figures were obtained on the motorway, both being taken at reasonably constant speeds. The low-speed run was made at approximately 38 m.p.h. and showed a consumption rate of 14.3 m.p.g. A full-throttle test at an average of 51.2 m.p.h. gave 8.19 m.p.g. Both fuel returns are surprisingly good in view of the average speeds.
A " British " Test 1 then made a third run under conditions more akin to those in Great Britain, the route chosen being a twolane undulating stretch of road between Landwetter and Rya. The round trip involved a distance of some 14 miles, which was covered at an average speed of 35 m.p.h. despite unhelpful -traffic conditions on the return leg. Occasionally I was driving at up to 50 m.p.h., but for the most part I endeavoured to keep the speed at a steady 40 m.p.h.
The fuel figure resulting from this rest was 12.25 m.p.g., which is about 2 m.p.g. better than .1 have previously obtained from British petrol-engined 5-tonners running under similar traffic conditions but at a lower overall average speed.
For the hill-climb the 5-tonner was taken up the northern side of Partille Hill, a loose-surface 11-mile-long gradient averaging 1 in 20. The climb was made in an ambient temperature of 66° F., and occupied only 3 min. 521 sec. The water temperature rose by ,9° F. above its normal figure of 144° F.
Lowest. gear employed was second, with the high axle ratio engaged, and this combination was required for only 15 steonds, during which ti't•Ile the minimum speed was 19 m.p.h. This climb was particularly rapid and high
lights one of the principal advantages of a VS engine.
A fade test was conducted down a 1-mile stretch on the southern side of the hill, the average gradient being I in 17. It lasted 2 min. 10 see. and was carried out by coasting down the hill in neutral and relying on the foot brake to keep the speed down to approximately 20 m.p.h.
At the bottom of the hill a fullpressure stop produced a Tapley meter reading of 73 per cent., which compares very favourably with a maximum figure of 79.5 per cent. obtained earlier in the day with cold drums.
1 next drove through the centre of Goteborg to a hill known as Krabbeliderne, close to the Norlanda Way, where there is a section of I in 71. On this slope the hand brake held the vehicle without any difficulty.
It was just possible to restart in second gear with the low axle ratio engaged, although I had to slip the clutch excessively and, once the clutch was fully engaged, the engine was turning at a very low speed. The performance was repeated several times. The slope was probably the steepest that could be tackled in second low gear, but gradients of up to about 1 in 3 should be manageable in bottom low.
My general impression of the Volvo as gained from the driving seat was of smooth, quiet and fast travel, the engine becoming noisy only when using peak revolutions. Cruising at 45 m.p.h. was effortless and, although a maximum-speed check was not taken, speeds reached during the day showed that this would be well over 60 m.p.h.
The seating, although simple, is comfortable and the relative positions
of the steering wheel, gear lever and hand-brake lever are a satisfactory compromise. The steering was unexpectedly heavy, this being accentuated by the small wheel, although the front-axle overloading would largely account for this characteristic.
Suspension was entirely satisfactory and for normal retardation high braking pressures were not necessary. The weather became hot during the day of the test, which led me to •note that cab ventilation was not ideal.
Engine Accessible Although there was no time to carry out maintenance checks, I was able to inspect engine accessibility, which was good. The upper section of the engine cowl is secured at the front by two snap fasteners and at the rear by two pegs which can act as hinges.
The upper cowl is easily removed, whereupon the two lower side sections can be detached without difficulty, thereby exposing all the upper part of the engine and its accessories. The engine position is such that the cab floor is level with the exhaust manifolds.
Attention to the valves, sparking plugs, ignition equipment, fuel system, and oil and air filters is first class, particularly when the seats are removed—a simple operation.
The Volvo L 43013 11-ft. 2-in.wheelbase 5-ton chassis and cab sells in Sweden for £1,450 in standard trim. When supplied with the Eaton twospeed axle, as fitted to the test vehicle, a further £87 is payable. It is much more expensive than British petrolengined 5-tonners, but the purchaser obtains a particularly high-quality product with a performance a cut above average.