Laverda V6
Agent Orange
The prototype V6 Laverda 996cc endurance racer which made a single brief but memorable appearance in the 1978 Bol d’Or 24-hour race, is widely acclaimed as the ultimate Italian two-wheeled tour de force of the Post-Classic era. Although riders Nico Cereghini and Carlo Perugini were forced to retire after eight hours with a broken final drive coupling when lying in a respectable 23rd place out of 80 starters, it provided a rare glimpse of a near-mythical motorcycle whose fame has far exceeded the sum total of its achievements – which are, basically, zero! For after that solitary outing, when its unique exhaust note thrilled spectators and was aptly described by one observer as sounding like ‘ripping silk’, the V6 Laverda was retired to the factory lobby as silent testimony to the company’s technical skills, as well as the Italian ability to harness enthusiasm and dedication in the cause of engineering innovation. Unlike the bigger Ducati or Moto Guzzi firms, Laverda was never a standalone motorcycle manufacturer, with its bike division very much a spinoff from its core agricultural machinery business, now owned by Fiat. But thanks mainly to the passion of Massimo Laverda, who took over Moto Laverda in 1964 at the age of 25, the family company produced a stream of high performance models, of which the 1000 Sei – the V6 Laverda’s official title – was the most prestigious. Two chassis were made and four engines, but just a single complete bike. Laverda SpA began life in 1873 as a manufacturer of farming implements, and it eventually became a leading agribusiness machinery producer, joined in 1949 by a separate motorcycle company. With the chronic need for personal transportation in postwar Italy fuelling a booming market for small-capacity motorcycles, Laverda began work on designing its own such bike in 1947. Success followed in the showroom as well as the racetrack, especially in Endurance racing which displayed Laverda products’ inherent qualities of durability coupled with performance. But the creation of the Laverda 1000 Sei came principally as an engineering exercise, as Massimo Laverda once told me before he sadly passed away in October 2005. “Honestly, we never had any intention to develop a V6 road bike,” said Massimo. “But we wanted to research new solutions that might be applied to the next generation of Laverdas. The water-cooled four-cylinder prototype we designed in 1983 incorporated
many of the lessons we learnt in the course of developing the 1000 Sei. It was always intended as a mobile testbed, and while of course we all said to ourselves how nice it would be if we ended up making a street version, there was never any real question of it. It would have required a far greater financial investment than a small company like ours could ever afford.” The leader of the 1000 Sei design team, working with long-time Laverda chief engineer Luciano Zen, and Massimo Laverda – himself a Mech.E graduate – was one of the most respected names in Italian automotive engineering, Ing. Giulio Alfieri. Creator of the iconic Maserati Birdcage sports car and 3500GT road models, and also responsible for developing the fabulous 250F Formula 1 racer, he’d worked for Maserati since 1953. When Alfieri left the company, Laverda hired him as a consultant with the aim of breathing new life into his company’s products. Alfieri had overseen the Merak V6 project at Maserati, and brought his ideas and experience to Laverda. Hence the first Laverda 1000 Sei engine was running less than six months after the project was initiated, and with its first dyno run yielding 118 bhp, the team knew their target of 140 bhp was within reach. The compact four-cam dry-sump 996cc V6 engine sees the cylinders measuring 65 x 50 mm arranged in two banks set at 90º for perfect primary balance. The four valves per cylinder employed a very flat included angle for the time of 28º, with a single central 10mm plug, and an unusual vertical inlet port design for a motorcycle permitting maximum downdraught from the six centrally mounted 32mm Dell’Orto carburettors carrying long velocity stacks reaching vertically upwards beneath the 24-litre fuel tank. The twin overhead camshafts per cylinder bank are chain-driven off a jackshaft running the whole length of the engine, itself also chain driven off the front end of the lengthways-mounted forged onepiece crankshaft, with each pair of forged steel conrods sharing a common plain-bearing big end. The dry sump motor’s five-litre oil tank is located under the seat, with a single large oil cooler complimenting the two large water radiators.
A skew gear off the jackshaft drives the large Marelli distributor mounted behind the steering head. Coupled with an ultra-costly Dinaplex electronic ignition unit from the same supplier, which was originally developed for the V6 Ferrari 246 F1 racer before being used in modified form on the Fiat Dino V6 coupé, this provides a high-intensity spark for 10,000 rpm-plus running. An electric starter is fitted, which together with the electric fuel pump and endurance race lighting, requires a hefty generator to charge the large battery mounted beside the oil tank on the right, under the seat. Ignition advance is a conservative 38º, and compression ratio 10.5:1, with excellent fuel economy. The five-speed gearbox is enclosed in its own separate casing bolted to the rear of the crankcase, originally with the shaft final drive running within the right side of the BMW-type swingarm. Rear suspension originally came via a long monoshock mounted lengthways beneath the gearbox, and
operated via a bell-crank system. But whereas the engine proved immediately successful in dyno testing, as soon as it was fitted into a chassis which employed the power unit as a fully-stressed member, with a triangulated tubular subframe bolted to the front of the motor to carry the 38mm Marzocchi fork, and the swingarm pivoting in the gearbox casing, the team’s problems began.
“Our difficulty wasn’t with the engine’s power, but with its transmission and the problems of torque reaction,” recalled Massimo Laverda. “There were two hurdles to overcome. First was that if you have a lengthways crankshaft in any bike, you inevitably suffer adverse torque reaction as the engine rotates across the frame. That’s not much of a problem with a 70 bhp BMW or Moto Guzzi, but with twice that output on our V6, we initially experienced terrible handling problems. The solution was to place the gearbox to one side, and fit a reduction gear to the clutch which rotates in an opposite direction to the crank. We also fitted a counter-balancer on the generator shaft, and the effect was that all the forces cancelled each other out. That was one problem solved – but the other one was much more difficult, because we had the same torque reaction problem at the rear wheel, which would rise and fall sharply on the suspension under acceleration and deceleration. Again, this isn’t a problem on less powerful bikes with shaft drive – I’ve been a BMW owner for years, and you just learn to live with it. But with 140 bhp, such a machine becomes unrideable, and I’m afraid that’s what the 1000 Sei was at first.” After some head-scratching the design team came up with an answer, namely to revert to a then-conventional twin-shock rear end, and to redesign the transmission casing so that the now much longer swingarm could pivot about the calculated centre of gravity of the engine – which proved to be the rear of the crankcase. This meant the forces were thus transmitted to the most perfectly balanced centre point of the bike, but the trouble was that this was so far from the final drive pinion that a two-piece drive shaft was now required, with a UJ coupling the two halves. Testing seemed to confirm this would hold up OK, so the team got down to completing the detail work before the bike’s debut at Paul Ricard in September 1978. Engine development had focused on yielding a wide and usable powerband, and the dyno sheets Massimo showed me dated Sept. 4, 1978, ten days before the race, indicated that with usable power coming in as low as 4,000 rpm, the motor used in the Bol d’Or yielded 138.7 bhp at 10,500 rpm, with maximum torque of 95.5Nm at 9,500 rpm. Weight was a handicap, though, because it had been decided not to use expensive magnesium castings while the bike was still being developed. So the complete 1000 Sei scaled 238kg ready to race with oil, water and half a tank of fuel, of which the engine/gearbox unit alone represented 175kg. But with a 1500mm wheelbase and 740mm seat height, the Laverda was as compact as any of its rivals, and at just under 530mm wide actually narrower than many of four-cylinder Japanese bikes. Almost inevitably, it was the one part of the 1000 Sei which the team were less than 100% confident about, which let them down, with the drive shaft UJ breaking after 8½ hours of what amounted to a
“... it had proved the efficacy of its engine design by recording a then-incredible speed of 283 km/h through the speed trap at the end of the mile-long Mistral straight...”
“The Laverda’s unique exhaust note, deep at low revs then gradually becoming shriller as the engine speed mounts, certainly lives up to expectations as much when you’re on board it as standing trackside.”
certainly have cured the Laverda’s transmission problem. But by then the decision had been made to retire the bike to the factory foyer, and employ the lessons learnt from building and running it on the company’s next generation of production motorcycles. The fact that, almost 40 years after it first appeared in public, the Laverda 1000 Sei still seems as technically avantgarde and innovative today as it did back then, is testament to the farsightedness of the men who produced it. My chance to sample the Laverda ‘Sei in Vu’ from the hot seat came after I managed to persuade Massimo Laverda to stop riding it around the factory test track with his trousers tucked into his socks! It’s getting dark, and any moment now we’ll have to see if those fat CEV-Marchal headlamps really work. Eventually Massimo pulled in, and handed the bike over. “Watch out for those tyres,” he warned, “they’re the same age as the bike, and the rear slick is the one from the Bol d’Or. Be careful – this is the only Mille Sei we’ve got!”
Alfieri’s V6 engine is practically bullet-proof, a sophisticated, reliable, basically under-stressed power unit that if it were to have been unveiled last month instead of 38 years ago, would still be hailed as a genuine advance in two-wheeled technology, especially with the mechanical fuel injection Laverda experimented with in 1977. On to the wide, comfy seat, flick the ignition switch to set the fuel pump ticking, thumb the starter button, and the V6 bursts into life instantly, to the accompaniment of a glorious wall of sound from the lightly-muffled six- into-two exhausts. The idea of counterbalancing the crank with the generator and ignition combining to produce the identical centrifugal weight, but rotating in the opposite direction, really works. The Laverda’s unique exhaust note, deep at low revs then gradually becoming shriller as the engine speed mounts, certainly lives up to expectations as much when you’re on board it as standing trackside. Thanks to the watercooling there’s not much mechanical noise for a late-’70s racer, though when you crank the throttle wide open, there’s noticeable
induction roar from the six-pack of Dell’Ortos. Equally surprising is the power curve, for to get almost 140 bhp at the rear wheel from a one-litre four-stroke was almost unbelievable in 1978. The engine really is so tractable that you can’t help but disbelieve Massimo Laverda’s fervent assertion that it was never intended to make a road bike from it – because that’s already practically what it is! The V6 pulls cleanly off the mark with only a little slip of the very light-action clutch, drives cleanly from as low as 2,000rpm, hits a hiccup at 3,500rpm thanks to the reverse-cone exhaust, then cleans out at 4,000 revs and runs effortlessly up to the 10,500 rpm redline.
The unsuitability of the Laverda factory track as a venue in which to ride such a bike soon became apparent. However, there was one lovely, long sweeping right hander where I could wind the V6 up into third gear at about 8000 revs, which provoked a sense of déjà vu as the essential understeering qualities of the long wheelbase chassis asserted themselves. Just like the old Dukes, the Laverda is a bike you need to send a telegram to when you want it to change direction on fast sweepers, a trait derived not only from the long wheelbase, but also from the wide 30-degree fork angle and undisclosed but substantial trail – I’d guess around 120mm. This cocktail does make for a very stable ride at the expense of it being quite hard to change direction with the bike, which is also inevitably cumbersome in tight turns. You need a lot of physical effort to lug it round such bends, in spite of the considerable weight being carried pretty low down.
Riding a bike like the Laverda round a glorified car park is like taking a Lamborghini shopping – it’s practically an insult. Yet the engine was so smooth and forgiving, with such a wide power band and flat torque curve, that it put up willingly with doing so. Except for a notchy change between bottom and second, which I put down to the typical problem of going through neutral on a shaft-drive bike, the left-foot gearchange with its evenly-spaced ratios was precise and acceptably smooth, and thanks to the resolution of the torque reaction problem, there was no pogoing up and down on the suspension when I changed up, nor did the gyroscopic effect of the crankshaft affect the steering. Still, you have to give the throttle a good blip changing down through the gears, but that’s no hardship with that glorious exhaust note! However, the one thing I really hated on the bike was the period Italian rocker-pedal shifter, which is supposed to let you use your heel to change up with, but only allowed my boot to get wedged inside it, provoking a couple of false neutrals. Under such circumstances, I was glad to be reassured later by Ing. Alfieri that his engine actually has a safe redline of 12,500 rpm, rather than the 10,500 employed for the Bol. But all too soon it was time for the concert to end. As I cut the engine and coasted to a stop, the crowd of onlookers burst into applause, saluting the genius of watching Alfieri and Zen, and the enthusiasm of Massimo Laverda, in creating this two-wheeled masterpiece, a milestone in motorcycle design. After riding the V6, I’m not surprised to learn that it’s done several hundred kilometres on the street as raced, but with a Prova licence plate fitted. Pity the poor Carabinieri who’d have to try to catch it with their Alfa Romeos....