Rover 3500 V8
Rover V8 is an exceptional car. Its small and lightweight V8 engine has rare
ability in relation to its modest cubic capacity, particularly in that it revs
African production, this automatic-transmission car was introduced a year or so
ago, with the lower "export" compression ratio of 8.5 to 1.
Warner three-speed transmission has a three-element hydrokinetic torque
converter coupling, capable of an infinitely variable rate between 2.1 to 1 and
direct drive. It is controlled by a smooth console-mounted selector which
enables the driver to hold individual ratios - but preferably only if he has a
rev-counter fitted and red-lined at 5200 rpm.
At the time
of our original Road Test of this car, with 8.5 to 1 compression ratio engine,
in February 1970, we guessed that in its high-compression form (10.5 to 1, as
marketed in Britain) it would be a contender for top honours among the
Republicīs performance models.
compression ratio is achieved merely by fitting a set of high-compression
pistons, which can be obtained in kit form at a cost of about R170, and would
involve something like R100 in fitting costs.
engine output by just under 14 per cent, and torque by 7.5 per cent, according
to factory specifications, at the same time increasing engine range from 5000 to
chance, the opportunity arose recently to re-test the same car, now fitted with
the high-compression pistons.
high-octane (probably 98) fuel just round the corner, we were able to push this
test into the realm of pure research by testing the high-compression engine
twice: with 100-octane racing fuel, and - subject to a 6-degree ignition retard
- on the standard 93-octane "premium" we have become accustomed to.
are something of a mixed bag, and do not necessarily give a decisive answer to
owners who may be considering uprating their carsī engines with high-compression
pistons when our new octane rating arrives.
is up - but not by a shattering amount - and fuel economy seems to be virtually
unaffected. With the proposed high-octane fuel bound to be up considerably in
price, this is an important consideration.
Performance - 93
set on TDC and the tank filled with 93-octane, we did a full set of performance
runs, using manual control to go to 5000 rpm through the indirect ratios. There
was a distinct gain in torque, affecting gradient ability and acceleration.
acceleration to cruising speeds as the most indicative, the improvement in
acceleration times averaged 5.4 per cent, while maximum speed potential goes up
slightly. Top-gear pulling power was considerably improved, particularly at
Performance - 100
was to drain the tank, fill up with 100-octane racing fuel, advance timing at 6
degree before TDC (factory specification) and re-test.
surprise: small improvements in acceleration and gradient ability, and slightly
more in maximum speed potential, with fuel economy again remaining fairly
constant - though showing signs of improving towards the high-speed range.
the improvement in acceleration times over our original test was 8.2 per cent -
only 2.8 per cent of it accounted for by the super-octane petrol!
potential in this form went up to 185.3 km/h (114.9 mph) - making this South
Africaīs top automatic-transmission car in terms of straight-line speed. Not
even some of those hairy big V8 models are likely to match this, except in
certainly showed that the Rover V8 engine, with its advanced design, is
extremely octane-tolerant. With 10.5 cr it performed perfectly happily on
93-octane fuel with TDC timing - indicating that owners on the Reef would
probably be able to operate with the raised cr on 93-octane at full 6-degree
question is: is it worthwhile doing the conversion on cars already built, with
the low-compression engines?
would be: probably not. Should Leykor at a later stage introduce a 10.5-cr model
to take advantage of better fuel, that is a different matter: we imagine buyers
would accept this very happily.
advantage of modifying an older car is not marked enough to be worth it, in
ordinary circumstances. The cost is fairly high, and the gain small. Our choice
would be to leave those low-compression pistons where they are!
CAR / South