A brand-new straight-six-cylinder, single overhead camshaft engine powers the new Rover 2300 and 2600, which Leyland have introduced as a lower cost, identically-bodied companion to the Car of the Year Rover 3500. They replace the Rover 2200 and Triumph 2000/2500 series. Prices start at £5,350 for the 2300 and £5,799 for the 2600.
The new “Six” is new from head to sump and shares no parts with any previous designs whatsoever. Only the crankshaft stroke and piston specifications differ between the 2300 and 2600 versions, apart from minor tuning items. The bore is common at 81 mm., but while the 2300 has a 76 mm. stroke, the 2600 has an 84 mm. one.
The gravity die-cast, cross-flow aluminium cylinder head has several things in common with that of the Dolomite Sprint, though it has but two valves per cylinder. each operated by the same camshaft. The inlet valve is operated directly by the cam, via an inverted bucket tappet, while the exhaust valve is actuated by a cast-iron rocker from the cam, which uses a toothed-belt drive for the first time on a Leyland engine. The combustion chamber is formed partly in a pentroof shape cast in the head, partly in the piston crown. Compression ratios are common at 9.25:1. Fourteen millimetre sparking plugs are used, as in the Sprint. The cast aluminium inlet manifold carries twin SU HS6 carburetters and the exhaust manifold feeds into twin down pipes. The block is a practically, symmetrical chrome iron casting, carrying the forged steel crankshaft in only four hefty main bearings, to reduce frictional losses. The symmetrical forged alloy steel connecting rods have fully floating gudgeon pins: those of the 2300 carry Hepworth and Grandage “W”-slot pistons, the 2600 Mahle solid skirt pistons. The oil pump is driven off the nose of the crankshaft, tho Lucas distributor off the camshaft.
The Leyland engineers seem to have used their clean sheet of paper to good effect, for the small engine gives 123 b.h.p. at 5,000 r.p.m. and 134 lb. ft. at 4,000 r.p.m., whilst the 2600 offers 136 b.h.p. at 5,000 r.p.m. and 152 lb. ft. at 3,750 r.p.m. This compares with 155 b.h.p. at 5,250 r.p.m. and 198 lb. ft. at 2,500 r.p.m. for the 3500.
Leyland’s excellent 5-speed gearbox, with the same ratios as the 3500, is fitted to the 2600 as standard. Standard wear on the 2300 is a four-speed version of the same gearbox, with five-speed optional. Borg-Warner 65 three-speed automatic transmission is optional on both models. Both models in manual or five speed trim use a 3.45:1 final drive, against 3.08:1 on the 3500 and the 2600 automatic.
Other differences are slight. The 2600 has self-levelling rear suspension, the 2300 does not. Power steering is optional on both. Both have 5J X 14 in. wheels and 175 HR14 tyres (the 3500 has 6J x 14 in. wheels and 185 tyres or 195/65 on the optional alloy wheels, which are available too on the 2600). Disc/drum brakes, etc., are as for the 3500, from which the two new models arc distinguished externally merely by different wheel treatment and a badge on the tail.
Owners of these cheaper models will lose out very little in luxury on the 3500 driver. Both have velour-trimmed reclining front seat squabs, folding rear seats and folding rear centre armrests, but the 2300 has a sewn pleated trim and the 2600 has box pleats. Instrumentation is similar on both models, but the 2300 lacks a tachometer and a couple of minor dials as well as the intermittent wiper control and a bulb failure warning light.
We were introduced to the new models in the Border Country north of Newcastle, still an area of modest traffic density and admirable road variety. We plumped for a 2300, four-speed manual, power-steered car first, expecting it to be a disappointment after our familiarity with the 3500. Not a bit of it! The engine responds to the key with a crisp, quite sporting note and it loves to rev. The gearbox needs stirring to obtain the b.est from the engine, but with such a delightful box, who cares! Engine noise is not what one would call inconspicuous, but it is not overbearing and is balanced by low wind and road noise. Acceleration lacks the scorching athleticism of the 3500, 0-60 m.p.h. taking about 11.5 seconds, but once this smooth six is wound up it flies along very rapidly indeed, an easy 90 to 100 m.p.h. cruiser, even without the optional fifth gear. Leyland quote the Maximum speed as 104 m.p.h. we saw rather more than that, quite exceptional for such a big car of modest capacity.
The ride and handling is much like the 3500, save that this writer and colleague both felt that this car’s handling benefited from the omission of the. self-levelling device, which sometimes goes out of phase under extremes of braking and cornering. The power steering was rather more accurate than that of the 2600 five-speed car we came to next.
We found the 2600 bit noisier than the 2300, with an engine note and feel not quite so smooth. But the extra torque and overall performance were instantly obvious, feeling not too far removed from that of the 3500, though Leyland’s 0-60 time of 10.7 sec. says otherwise. Both cars felt very deceptively slow when true speeds were very high particularly in the 2600’s fifth gear – and the driver needed to keep a watchful eye on his speedometer.
There is not a lot more to add, for in all other respects – brakes, comfort, convenience, appointments these new models re-affirmed everything we have said previously about the exceptional 3500. In retrospect we found the 2300 the sweeter car of the two sixes, though its quoted touring average economy shows no benefit at all over the 2,600 at 26 m.p.g. and only 1.7 m.p.g. improvement on the thrifty V8.
Leyland are tilting particularly at Granada sales with these new models. Having driven both Ford (the new model) and Leyland offerings we can say that they are alike as chalk and cheese. The Rover is definitely more sporting, tauter in its ride and harder on the ears, reminiscent of a BMW “six”. The new Granada is a “softer”, quieter car. The choice is one of matching human temperament to motor car temperament.
It will remain to be seen whether Leyland have done the right thing in putting all their eggs into the hatchback basket in this market sector. A conventional three-box alternative might sorely have been a good idea? After all, the Audi too has topped the so-called “executive car” charts for two months running. – C.R.