SEARCH FOR POWER

Press, 19 October 1978, Page 8

SEARCH FOR POWER

Almost from the time ] when motorised vehicles made their first appearance. owners, drivers and manufacturers have been striving to make them I go faster, often in the teeth of legislation which did (and still does) its best to make I them go slower. At the outset, progress was not very startling, being hampered by inferior fuels which limited the usable compression ratio, inadequate materials which limited rotation speeds, and only a rudimentary knowledge of the principles controlling combustion, which restricted the power output still further. As a result, at the start of the century one was lucky to get more than 6 b.h.p. per litre, even from a racing engine, whereas today 10 times that power is obtained from saloon car engines. To get high actual power it was necessary to use a big engine, and some of the early racers were really big. ranging from 10 to 16 litres. However, it was found that their very weight and size were their undoing, and capacities began to decrease, a trend which was shortly enforced by race organisers placing various restrictions on design. Many of these early machines were quite simple in concept, one exception being the Blitzen Benz with four overhead valves per cylinder, but the most significant forward step was made by the Swiss engineer Henri, who in 1912 pioneered the double overhead camshaft, four valve arrangement which eventually • became the classic layout for high performance e engines. The 7600 c.c. Peu- i geot fitted with this engine t developed around 140 e b.h.p., thus providing 18 v b.h.p. per litre at the then a high speed of 2200 r.p.m. t The need for aircraft v engines of light weight and ii great reliability during c

World War One intensified the quest for superior materials, especially in pistons, valves and valve springs. Afterwards the automotive industry were quick to avail themselves of high strength aluminium 4 alloys, austentic valve steels and silicon-man-ganese springs which metallurgists had developed. These permitted a great rise in engine speed, with improved reliability, but it was mainly' Ricardo’s postwar work on methods of suppressing detonation which led to significant gains in power by allowing much higher compression ratios to be used. Following the aircraft lead, engines with eight cylinders in line became popular although the “four” retained its place to some extent. One example was the 3 litre, four-valve Vauxhall, developing 130 b.h.p., but by 1922 this power was equalled or exceeded by 2 litre engines such as the Sunbeam and Fiat. By 1927 the International capacity limit was reduced to 1.5 litres, but supercharging and alcohol fuel was allowed. One of the most remarkable units produced to this formula was the straight eight Delage, producing 170 b.h.p. at the then ••.ilossal speed of 8000 r.p.m. At these revs the piston speed was 4000 ft per minute, which blew skyhigh the theory that this figure should not exceed 3000 ft per minute. A few years later the giants came back again, typified by the 16 cylinder, 6 litre Auto-Union, supercharged to develop 520 b.h.p., and the slightly smaller Mercedes turning out 646 b.h.p. at 12 pounds boost, the highest power ever used in a road racing car. The Second World War ended this phase, as when racing was resumed it was with much smaller and less expensive engines, mostly with atmospheric induction and after a while without : the benefit of alcohol fuels ; which provided a valuable interna] cooling effect. Single- ’ cylinder car engines as power

I producers, pre-war examples- ■ being able to turn out over i 20 b.h.p. per litre thanks to : the use of resonant or] i “tuned” inlet and exhaust! : systems. I ; Freddy Dixon turned his ‘ motor-cycle knowledge to the I : most effective use by con- I ■ verting his Brooklands Rileys; to this system utilising one I carburettor per cylinder, andthis became the standard layout on post-war units, in: particular the Coventry;] Climax which in its final 1.5 litre. 8 cylinder form was ! able'to develop 210 b.h.p., 401 h.p. more than the 1.5 litre] supercharged Delage, while] the current 3 litre CosworthFord achieved some 410 b.h.p., about 3.5 times as much as the 3 litre Vauxhall. In the early days most builders designed and made almost every part of the engine, and guarded their secrets very closely. Then the specialists made their appearance and by concentrating on one type of product and amassing much data from a number of engines they began to develop very high - grade components, which were able to stand up _ to the steady rise in thermal ] stresses and mechanical | loads created by the in-1, creased powers. Firms like Well worthy, for] instance, concentrated on 1 piston rings and conducted a! racing service department to ] look after their customers m i the field. Thereby not only improving their product but also gaining valuable publicity from their racing successes. Piston makers such as Hepworth and Grandage in England and Mahle in Germany, followed the same course, as did bearing makers like Glacier and Vandervell. Racing designers have a habit of pushing the available materials and products up to or even beyond their limits and rely on metallurgists to discover still better materials and processes to meet their demands. Much of the knowledge] I which has been gained in] this highly competitive field]! has been passed on to the i makers of “cooking” engines, and is one reason for the long-wearing properties and reliability of the modern touring car engine.

For the few who contemplate New Zealand’s driver licence tests and qualifications with just a little trepidation, here are a few facts from the United States.

In New York, a prospective driver must be 18 before qualifying. A junior licence may be acquired at the age of 16 or 17, but several restrictions are applied. Even before applying for a licence, a vision test must be passed requiring visual acuity 20/40 or better in either or both eyes, with or without glasses. Then a written and a road sign test must be passed and the applicant may apply for a licence. Should learners not feel confident of passing the practical test, they may practise, after applying for a 'learner’s permit. The state’s “Drivers’ Manual” (the equivalent of our road code) suggests 20 hours of practice, with five of these in moderate to heavy traffic. During this practice time, the learner must be accompanied by a qualified instructor or parent.

Once, these preliminary preparations are complete, the big. test comes, with testing done by a driving examiner.

This test is not much different from the New Zealand equivalent, with hili starts, parking procedures and general driving attitudes being taken into account.

If a test is passed an interim permit is issued entitling the holder to drive for up to 45 days. This allows time for a punch-card licence to be mailed to the applicant and returned. The card is stamped and part of it is returned as the driver’s licence.

The driver is on “probation” for the first six months. In this time the driver must not be convicted for violating speeding, tailgating, reckless driving or alcohol and driving laws, or receive two convictions for any of the “moving offences” under the state’s points system.

In the event of any of these convictions the licence is immediately annulled.

Sixty days must transpire before a driver may reapply. The usual procedure, including the probation period, is repeated.

With New York City boasting a population in excess of 10 million, the state’s licencing laws may be considered to be completely justified.