U.S. COMPETITION Measured with a Reo
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--First Road Test of the Reo 7-tonner Proves Overdrive Gear Fully.Justified. Interior Insulation of Cab Effectively Dampens Exterior Noise
By L. j. COTTON, M.I.R.T.E.
BECAUSE of import restrictions, Reo Vehicles will not be generally available until the Government's present policy is amended The two chassis on view at Earls Court were imported for exhibition purposes only, but with the co-operation of the conces, sionna ire, a body was fitted to the 7-tonner and put at my disposal for test. This is one of the latest models of the range.
This vehicle presumably typifies the trend of Reo design, and this report, besides proving the capabilities of the machine, may be used to provide a comparison with the design and performance of homeproduced vehicles Although the earlier frontal styling is retained, the new model has a more powerful engine. vacuum-assisted brakes and a short wheelbase. The title of" Moreload has been given to it because of the greater load space per inch of wheelbase Retaining the 3!.-in bore. the stroke of the Gold Crown 288 engine has been increased to 5 ins., :dying a power output of 96 b.h.p. at 3,000 r.p.m. (72 octane fuell, which is equivalent to 20.34 b.h.p. per litre Lengthening the stroke has been the main modification to the engine, and in most other respects the power unit is identical with earlier models
No liners are Iitted *to the cylinder bores, the pistons operating on the parent metal--chrome molybdenum steel. Renewable exhaust-valve seat inserts of similar material are shrunk to fit into the block. The crankshaft is Tocco-hardened and carried in the case by seven steelbacked copper-lead-lined bearings having a total area of 88,2 sq. ins. The same form of bearing is used for the connecting-rod big-ends.
The aluminium Lo-Ex pistons are cam-ground, and equipped with three compression rings and one scraper ring. The gudgeon'-pin bushes operate in bronze bushings and are retained in position by lock rings.
Engine accessories include • a replaceable starter ring, thermostat. Fram oil filter, centrifugal advance and retard ignition arrangement, and an oil-bath air cleaner.
The single-dry-place clutch has thermoid-woven friction discs of a total surface area of 149.2 sq. ins Mounted as a unit with the engine, the five-speed overdrive-top gearbox has helical gears for the third and fifth ratios, fourth gear being direct
drive.
Spicer needle-roller bearings are fitted to the two propeller shafts. Hypoid bevel gearing is employed for the final-drive unit, which is carried in a forged banjo casing. .
An improvement has been made in the braking system by the adoption of the Westinghouse vacuum booster to the normal -hydraulic arrangement. When the pedal is depressed. air is
exhausted from one side of a 14-in,diameter diaphragm, which, connected to the hydraulic master cylinder, applies the brakes at all four wheels. The rear-axle shoes are self-energizing.
Following American practice, the electrical equipment operates on a 6-volt circuit, with positive earth return. The wiring -is encased in a waterproof and acid-resistant plastic' • covering and grouped into a harness.
Driving comfort has been studied, the entire cab being sound-deadened, fully lined with trimming material, and the floor covered with a jutebacked rubber mat. Both the seat back and cushion are adjustable for height and rake. A small but important feature is the de-froster openings in the dashboard, which keep the windscreen clear in cold weather.
Forward and rearward visibility is excellent, the rear glass being 11 ins. deep and 30 ins. wide. Instruments include a water-temperature gauge. ammeter, oil-pressure gauge, speedometer and fuel gauge.
I collected the Reo from the service station at Brentford, and weighed it unladen on the public weighbridge. For a 7-tonner the unladen weight of 31 tons is relatively light, and indicates the general construction of the chassis. The payload, two iron castings, each weighing approxithately 4 tons, was lent by A.E.C., Ltd., Southall. When the castings were being lowered into the body, care had to be taken to position the legs of each casting over the body bearers.
Leaving the A.E.C. works at Southall, my first objective was to test the heavily laden Reo on the hills in the Harrow area. In climbing the incline from Greenford to Harrow School, the driver changed through the gears to the lowest ratio. Had the engine been governed at a higher speed, I think the climb would have been made comfortably in a higher ratio. As it was, the low road speed did not give full opportunity of making the most of the engine power available.
Peterborough Road, a longish incline of severe gradient, required full use of bottom gear, and the water temperature rose by 15 degrees
to 165 degrees F. Ambient temperature was 55 degrees F. The 1-in-6 gradient from Yew Walk to Harrow High Street provided ground for the stop-start test, and apart from the simultaneous operation of the clutch, foot brake and accelerator pedal, there was no difficutly in restarting.
When driving to the Great West Road for the extended trials, I found the Reo a comfortable vehicle to handle. All the controls were within easy reach, and the gearlever travel remarkably short. My attempts to make silent gear changes were not successful in the earlier part of the day, but when I became more accustomed to the spacing between the ratios, my efforts were rewarded.
Rear Axle Loading The steering was exceptionally light, the reason being found when checking the weight distribution. An analysis of the weighbridge figures showed that 21 per cent. of the 11 tons 6 cwt. gross running weight was being carried by the front axle, and nearly 9 tons •by the back axle— nearly a ton over the legal limit for this country. It must be understood, in fairness to the test, that the payload was nearly a ton over the liMit advocated by the concessionnaire.
When making emergency brake applications from 30 m.p.h., the Reo came to rest in 75 ft. from 30 m.p.h., there being a tendency for both front wheels to lock. All four wheels braked evenly from 20 m.p.h., the average at the stopping distances being 24i ft In general terms, the relative braking efficiency from the two speeds represents 40 per cent. and 55 per cent. respectively. This model had not been previously tested nor any adjustments made since its arrival in this country, and I think that with slight adjustments to the brakes their efficiency could be improved.
The overdrive gear was not used in the acceleration trials, direct drive being engaged for top-gear acceleration and when making the 0-30 m.p.h. test. For a medium-sized vehicle the Reo has a generous power-to-weight ratio. Accordingly, the acceleration characteristics should be good.
This proved to be the case, but better results might have been obtained had the engine been governed to a higher speed. From an average of the results, 30 m.p.h. was reached, from rest, in 44.8 secs. Employing top gear only, it took 50.6 secs. to reach 30 m.p.h. from a rolling start of 10 m.p.h. Slight hesitation of the engine at low speeds prolonged direct-drive acceleration.
When making these trials there was a noticeable absence. of engine and transmission noise; in fact, it is the _quietest commercial vehicle that I have encountered. Whether this attractive feature has been attained by the design and manufacture of the chassis or by the sound-proofing of the cab is a matter to be decided by subsequent operation. To silence possible mechanical noise, the third and overdrive gears are machined with helical teeth, and air-induction roar of the petrol engine is effectively dampened by the oil-bath air cleaner.
Fuel-consumption tests were made between London Transport's Staines garage and the Rath Road, a course which, perhaps, is favourable, but one in which full use could be made of the overdrive. Having discon • nected the main fuel supply and brought the small test tank into use. I started the test.
On the Overdrive . After accelerating rapidly through the gears, the overdrive, was engaged at 28 m.p.h., and we sped silently along, maintaining a ,road speed of .25-35 m.p.h., according to the density of the traffic. With the traffic lights at the ." Staines reservoir in our favour; the inward --run was concluded without stopping. The return jotirney was made with the same good. 'fortune, and there was no occasion to employ the direct drive or intermediate ratios.
In covering the course the Reo used fuel at the rate of 10 m.p.g.. and I at an average speed of 29.5 m.p.h. An extended test of one stop per mile, representative of short-distance haulage, increased the consumption rate to 7.6 m.p.g. Far from being an additional gear, to be employed only when running light. the overdrive can be fully used on short hauls.
On concluding these trials the main fuel supply was again brought into play, and we started the return journey . to Southall for unloading. Driving along the Great West Road. which was comparatively clear of traffic, I was tempted to increase speed from 40 m.p.h. to 58 m.p.h.and then came a traffic baulk to spoil the fun Maximum of 63 m.p.h.
In fact, this model has a maximum speed of 63 m ph. at governed engine revolutions. With the restrictions operating in this country the maximum speed would have little sales value, but it is a matter of importance in many other parts of the world. As it is, the overdrive is justified, for employment in this country, from the results of the economy trial.
Although a mass-produced vehicle, built at a competitive price, the Reo is remarkable for the study of cab comfort A driver could spend long spells at the wheel without fatigue and the sound-deadened interior alleviates the _ mental strain of driving.
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