Two brand new designs appeared for the Spanish G.P., the BT26 Brabham-Repco and the RA301 Honda V12; in addition there was a redesigned Lotus 49, a second 1968-Cooper T86B, a new Ferrari V12 to the existing pattern, a new MS10 Matra-Cosworth, a new BT24 Brabham-Repco V8 to 1967 specification, and McLaren had a third M7A almost complete, but dismantled and stowed in the transporter, so that with the exception of the Eagle team, who were not present, everyone seemed well advanced and ready for an active Grand Prix season.
In spite of a lot of work to do on their Indianapolis cars, the Brabham team worked non-stop and chartered a special transport aircraft to fly their 1968 Grand Prix car out to Madrid in time for the last practice, on Saturday afternoon. This new car, BT26-1, is a new departure; the Tauranac-designed chassis uses stressed aluminium sheet in its construction, instead of relying solely on round and square section tubing. The chassis is still a space-frame following the previously successful designs of Ron Tauranac, but around the cockpit area aluminium sheet is riveted to the tubes to provide extra stiffness in torsion, rather like F. W. Dixon did with his Rileys in the early nineteen-thirties. It is neither a space-frame, nor a monocoque, but a sort of “half-coque”, and it is interesting that while Tauranac is cautiously moving from space-frame towards stressed-skin, or “monocoque” in popular terms, other designers are moving from the complete stressed-skin structure towards the addition of tubular structures, so that later this year we may see an ultimate compromise. The suspension and running gear of the BT26 follow previous Brabham layout and the fuel tanks are still separate components hung pannier-fashion by straps on each side of the frame along the cockpit sides and forming the body shape. The most important part of the new Brabham is the Repco-Brabham V8 engine, it being the new Type 860 all-Australian four-overhead-camshaft, 90-degree V8, with four valves per cylinder, and a nicer looking, clean and compact engine would be hard to design. The porting is conventional, with the inlets in the vee of the engine and the exhaust ports on the outside, and Lucas fuel-injection is used. The exhaust pipes end in long thin megaphones, stamped “Lukey Muffler” as on all Repco V8 engines, Len Lukey being an exhaust pipe and silencer manufacturer in Australia who has been a friend of Jack Brabham for many years and used to race a Cooper-Bristol along with Brabham before they found out about European racing. This brand new Repco V8 “four-cammer”, as it is known, is coupled to a new version of the ubiquitous Hewland gearbox, combining heavy-duty crown-wheel and pinion unit with lightweight gearbox assembly. It must have been heart-breaking for the Brabham-Repco people when the new engine broke before it had even started going fast, but at least they learnt something, whereas if they had not made the big effort to get to Jarama they would probably not have even got the car running when they did, and would have been that much behind all season. It will be recalled that Brabham tried out a new Repco V8 engine in practice at the first European World Championship event last year, at Monaco, and that broke before it got going properly. In view of the Repco V8 results of 1967 it could be that the un-auspicious debut of the “four-cammer” this year is a good omen. The Brabham team’s second car, which Rindt drove, was BT24-3, a car virtually identical to the two cars used last year and sold in South Africa, with a single camshaft to each bank of cylinders Repco V8 mounted in their orthodox space-frame.
The brand new Honda, designated RA301-801, was making its first public appearance and could best be described as a product of “John Surtees Enterprises”, which seem to encompass people and firms from Slough, England, to Tokyo, Japan. This new Honda has a full riveted aluminium-sheet stressed-skin “monocoque” chassis extending to the rear of the car, with the V12-cylinder engine mounted in the cradle formed by the two side-members. Front suspension is by double A-brackets, the top one with a forward bias, the bottom one with a rearward bias, and with a coil-spring/shock-absorber unit interposed. The “monocoque” finishes in a front bulkhead and forward of this is a light tubular structure which carries the radiator and the mountings for the anti-roll bar. At the rear the chassis ends in another bulkhead which carries the rear suspension members, the layout being conventional in having a lower A-bracket and single upper transverse strut on each side. There are the usual two radius rods on each side, and while the lower ones are attached to the chassis, the upper one’s are attached to a tubular hoop that runs upwards and over to form the regulation crash bar, or roll-over bar. This hoop is rigidly fixed to the “monocoque” by three bolts on each side and can be removed, the point being that if for reasons of suspension geometry Honda want to alter the chassis pick-up point of the upper radius rods, they merely have to replace the tubular hoop with a different one, rather than riveting new pick-up mountings on the chassis. The 12-cylinder engine utilises the same roller-bearing bottom end as last year, with the centre gear drive to the camshafts from the crankshaft, and centre power take-off shaft, but the cylinder heads are entirely new. They still retain four valves per cylinder, operated by two overhead camshafts, but use a valve gear like that on the successful 1-litre Formula Two engines of 1966, with torsion-bar valve springs operated by small forked levers under the valve-stem cap. Inlet ports are now in the centre of the vee of the engine and exhaust ports on the outside, the exhaust system being rather unwieldy as it winds its way up and over the rear suspension, compared with the Cosworth V8 or the Brabham-Repco V8. Honda use their own fuel-injection system and their own gearbox/final drive assembly.
The Gold Leaf Team Lotus had Lotus 49/1 as raced at the B.R.D.C. Silverstone meeting by Hill and, in addition, 49/5 which appeared rather hurriedly prepared for the Race of Champions at Brands Hatch. However, since that race 49/5 has been entirely remodelled and represented some new thinking for Team Lotus, though it was so new and untried that while 49/1 was in good working order it was kept under a sheet and did not run at all during the meeting. In place of the ZF gearbox used for so long by Lotus, this latest car has a Hewland gearbox, and the rear suspension mounting points are no longer on small tubular struts attached to the engine, but are on a very substantial fabricated box-section sub-frame, the upper pivoting points being much more widely spaced. A neater and smaller oil tank than used at Brands Hatch is mounted over the gearbox, with an oil cooler above it. On each side of the nose of the car are large horizontal fins, each presenting nearly a square foot of area, and they are mounted so that they can rotate about their leading edge through an angle of some thirty degrees. At the moment they are adjustable from outside the car, fixed by a pin that locates in one of a series of holes in the nose panel, but it is quite likely that future development will see these small “wings” controlled from inside the cockpit. A complete break-away for Lotus Grand Prix cars is the fitting of a cover over the entire engine and gearbox unit, shaped with a rising surface towards the end and finishing in a sharp cut-off, to form the flat wedge effect, as used on the Indianapolis turbine Lotus. In the top surface is an N.A.C.A. duct to feed air to the oil cooler. It is interesting that someone is thinking along proper aerodynamic lines for Grand Prix cars for, since the days of Connaught and Vanwall, scant attention has been paid to the advantages of good airflow on a Grand Prix car. It will be interesting to see this new Lotus in action at Spa. The other Lotus at this meeting was 49/2 which the Walker-Durlacher team are using until a brand new one is ready for them later in the season.
The Ken Tyrrell Matra-International ‘ream had a brand new MS10 car with Cosworth V8 engine, this being number two chassis, while number one was in the transporter as a spare, and a nice touch was the printed instructions in the cockpit, written in Spanish, explaining that the two small spanners were for removing the steering wheel in case of accident and the driver being trapped in the cockpit. Some day someone will think of using the simple idea of holding the steering wheel on a spline with an over-centre catch as Mercedes-Benz used to do, so that it is quickly detachable.
Cooper had two 1968 cars, virtually identical, apart from different suspension mounting points on the chassis to give improved geometry on the second and newer car. Both were using V12-cylinder B.R.M. engines with Hewland gearboxes. B.R.M. themselves had three cars, P126-03 which poor Mike Spence should have driven, the transporter having left Bourne before his death, and P133-01 and P133-02 for Rodriguez. The Tim Parnell team had the original Len Terry-designed car P126-01, which Courage was driving, all the Bourne cars using Hewland gearboxes.
McLaren brought his team in a well-prepared state, with M7A-1 for himself and M7A-2 for Hulme, and a third car in spares form; they also had two spare Cosworth V8 engines, as well as alternative nose cowlings, which were shorter and with larger apertures in view of the likelihood of high ambient temperatures. As the Cosworth engines had been showing signs of using more oil than expected during a race, the exposed cylindrical oil tanks at the rear were increased in capacity. For both cars there were sets of pannier petrol tanks, mounted on tubular outriggers, these riveted aluminium tanks containing rubber fuel bags, and when finally coupled up will be filled from the scuttle filler. The object of these pannier tanks is to get the weight spread wider and lower, for when in use the large tank over the driver’s legs will be dispensed with. At Jarama they were tried experimentally from the mechanical attachment point of view and contained no petrol.
The Ferrari team had three cars at the circuit, all to the same specification, but only two were used, Amon driving 0007 and Ickx the brand new 0009, while the even newer 0011 was not used. The four-valves-per-cylinder, single-ignition engines were installed, with inlet ports along the outside of each cylinder head, and exhaust ports in the middle of the vee. The engine sits very low within the deep side members and is a very tight fit in the confined space. Just behind the cockpit, air scoops direct a cooling draught along the side of the crankcase. The Lucas fuel-injection metering unit has now been moved from the rear of the engine to the front of the left-hand cylinder head and is mounted vertically, driven by skew gears off the front of the exhaust camshaft. The roll-over bar has been redesigned and made larger, and covers a small petrol cooler element, mounted behind the driver’s head. Although Amon’s car started life as a 1967 model it has gradually been modified and is now to full 1968 specification, identical to the two new cars, which are logical developments of the original design, rather than entirely new designs.—D. S. J.