By: Phil Schilling
Published in March 1972 Cycle Magazine
The machine was complex, the name simple. The V8. Motorcycling plays at numbers; there have been singles, twins, triples, fours, fives and sixes. But in the numbers game, eight is zenith. The V8. Those five characters label one thing, and one thing only: Moto Guzzis 500cc, four-stroke, water cooled, twin double overhead camshaft, 12000 rpm roadracing V8, which mounted eight carburetors, eight ignition coils and eight exhaust pipes, and which bristled with oil lines, water pipes, hoses and ignition wires. Conceived in 1954 and raced through 1957, the V8, Moto Guzzi believed, would break the Gilera grip on the 500 World Championship, shove aside MV Agusta, the pretender to the crown, and establish Guzzi hegemony in the 500 Grand Prix classics. But before the V8s imposing technology could finally shape and control race results, Moto Guzzi withdrew from international racing, and the V8 passed into legend.
Bill Lomas remembers. He rode the V8. Lomas, twice 350 World Champion on a Guzzi single, remembers the sound of the eight, the feel of it, the power of the thing, the struggle with it, the frustration, the excitation. Lomas remembers Giulio Carcano, who designed the V8: "A careful calculating plotter, Carcano could turn his mind to any aspect of motorcycle design, be it engine, frame or aerodynamic layouts."
Carcano plotted the V8 over a meal after the Spanish Grand Prix of 1954. The 500 Guzzi single had been played out; no matter how small, light, compact and streamlined, lack of horsepower doomed the banger. Carcano ruled out a four; Moto Guzzi already had an old in-line shaft-driven four that couldnt match the transverse fours of Gilera and MV. Lomas knew Carcano had no four cylinder enthusiasm: "He said that to beat the fours, there was no use building a four, as even after the development was completed, the new four would only be on a par with the opposition." And a transverse six, Carcano feared, would prove too wide and weighty. So despite its complexities, a water cooled V8 had merit. Since each bank would only contain four cylinders displacing 250ccs, the V8 could be narrower than a transverse air cooled 500 four. Carcanos design packed the greatest number of cylinders into the smallest possible area. His formula for success hinged on the numbers game: increase the number of cylinders, increase the piston area, bump up the rpm, pump more fuel and air mixture through the cylinders, and reap more horsepower. The gods of scientific numbers were on Carcanos side; the V8 would eventually outgun the fours, just as the fours had shot down the singles.
Carcano had no army of technicians, no task forces, no teams of specialists, no computers. He had his head, his experience, his riders and the eleven people in Moto Guzzis racing department. So they began. The factory sanctioned the design in September 1954; by Christmas the castings were being machined; two months later, in February 1955, the V8 first ran; and in April 1955 the complete bike underwent its first tests at Monza. In eight months Carcano and his men had translated an idea into a running model.
The V8 possessed fashionably oversquare dimensions; bore and stroke of each 62cc cylinder was 44mm x 41mm. Each bank of cylinders had double overhead camshafts; and an assemblage of six spur gears, enclosed in a gear case on the right side of the engine, drove the four overhead cams which opened the valves through overhead bucket tappets. There was nothing in this two valve per cylinder layout which was extraordinarily different from other contemporary efforts, except for the fact that the new Guzzi had four more cylinders and eight more valves than anything else. And it worked.
The heads and block of the water cooled engine were alloy castings; wet cylinder liners screwed into the block, and the heads had cast-in water jackets. The drive for the water pump came off the camshaft geartrain. The radiator rode down low in front, outside the front downtubes of the frame. The oil pump ran off the camshaft drivetrain, and the massive single top tube of the frame doubled as the oil tank for the dry sump engine.
The crankshaft spun on five roller main bearings. The crankshaft throws were at 180 degrees, and on each throw two connecting rods ran side by side. The layout and construction of the lower end underwent a series of changes as Moto Guzzi tried to build greater reliability and longer life into the crankshaft assembly.
Two large housings, each containing a set of four points, were located on the left side of the two intake camshafts. Two trays, flanking the radiator, each held four ignition coils which fired 10mm spark plugs. Two six volt batteries provided the power for the ignition system; with no generator or alternator, the V8 had a "total loss" system.
Eight tiny 20mm Dell Orto carburetors, sprouting long cylindrical intake trumpets, crowded between the cylinder banks like fingers in a pair of tightly folded hands. No space was wasted because there was none to spare. Sandwiched between the contact breaker housings, two float bowls fed both quartets of carburetors.
Four small exhausts for the front bank, straight pipes with no megaphones, hooked beneath the engine. The pipes from the rear cylinders snaked back between the frame members and the rear tire.
The oil bath gear primary on the left side coupled the output shaft to the dry multi-disc clutch. The gearbox was a four speed item, though Carcano left room in his design for six speeds. But the engine needed only four speeds, it had a band of power that stretched from 7000 to 12000 rpm.
Lomas recalls the first time the engine went on the dyno. "The very first power reading was 62 bhp at the rear wheel, where all other Guzzi power readings were taken. They had been misled years before by supposed shaft increases which never showed up on the road."
"One mechanic named Pommi did all the V8 engine building. Carcano himself did or supervised all the engine testing. The setting of the carbs was decided finally by running the engine in a darkened room and noting the red hot color of the exhaust pipes. Never at any time was it necessary to scratch for more horsepower."
Using the power was another matter. At first glance, the rigidity between the steering head and swing arm mount might seem questionable. The pivot boss for the rear swingarm was part of the transmission casing; the engine/transmission package bolted into the double downtube frame which cradled the engine. The enormous top tube that clutched the steering neck ran like a huge metal telephone pole over the engine; back behind the engine the rear cradle tubes rose up, turned 90 degrees inward, and joined up with the monster top tube which ended under the saddle. The frame design might allow the engine and swingarm to twist one way, the main cradle and steering head in another way. A nice theory perhaps, but Lomas has a much more direct explanation.
"Since there was only one complete machine, extensive handling tests could never be carried out. The handling problems, I felt, were due firstly to the very light weight of 148 kgs. (326 lbs.), and secondly to the fact that the carburation couldnt be cleaned up perfectly. This was due to having the float chambers situated on the left side of the engine, feeding the eight carburetors from a gallery. Depending upon which way the machine was leaned over in a corner, the carburetion was either weak or rich." The leading link front suspension may have led to some flexibility and insensitivity in the front end; had time or numbers permitted, telescopic forks might have appeared on the V8. In any event, tire technology handicapped the eight. "The tires available in 1955-57 just couldnt cope with the power (despite the unusual 20-inch rear tire). So the V8s riders all had very hair-raising moments."
Carcano continued to refine the eight, and the engine responded by producing more and more power. "By the end of 1955 the V8 was certainly faster than any of the opposing fours. For 1956 an increase in the carb sizes of one millimeter, and an increase in the exhaust pipe diameter of two millimeters, and raising the compression ratio to the highest ever at just over 10:1, put the power to 72 bhp at 12000 rpm. This certainly wasnt the maximum power point; the crankshaft and big end life dictated a 12000 limit."
Lomas planned to race the V8 himself for the first time in the 1956 Dutch Grand Prix, but in practice the eight lost the big end of a connecting rod. Connecting rod failures forced experimentation in the lower end layout right into 1957. The original setup, a one piece crankshaft with two piece rods running on crowded rollers, failed; so did experiments with split cage rollers and plain bearings. The final solution was a built-up Hirth style crankshaft: splined crank throws pressed into serrated crank wheels with interior bolts through the throws to lock the assembly into alignment. One piece rods then turned on normal rollers.
At the 1956 Beligium Grand Prix, Lomas and the V8 made the race, right on the pole. The flag dropped, and John Surtees on the MV four jetted away with Geoff Duke in pursuit. Duke caught Surtees and stretched out a lead in short order; Lomas, lying third with the V8, began reeling in Surtees. But on the fifth lap, the eights ignition scrambled. Lomas retired. Dukes Gilera stopped and Surtees won. But the V8 had served notice.
The German Grand Prix, Solitude, 1956: Lomas and Duke, side by side on the starting line, rocketed away in company with Reg Armstrong on the number two Gilera. At the end of the first lap, Lomas and the V8 wailed across the start/finish line ahead of Duke and the Gilera. The battle wore on lap after lap. Lomas remembers: "I had the V8 handling very well at Solitude, and in this terrific race with Dukes Gilera, I always had enough power to relatively play with the Gilera, which finally blew up, leaving me with a 45 second lead. But then the rear water hose split, scalding me and putting me out of the race. Yet the factory was pleased because they realized they had the basis of a world beater." The V8 had served notice again; it had the numbers and the horsepower to put the fours away.
The 1956 season ended at Monza with the Italian Grand Prix. Lomas came to Monza, having already nailed down his second straight 350 World Championship on the 350 Guzzi single. Lomas fell off in the 350 race and broke his wrist, while scrapping with the new 350 Gilera fours. So Keith Campbell took over the Guzzi in the 500 race. The V8 DNFed.
Nineteen fifty-seven promised to be the year of the V8, the year the numbers paid off, the year Lomas could become the 500 World Champion. "For 1957 no further power was necessary and all the time was spent on crankshaft development and handling mods. In the spring of 1957 we went down to Rome for a publicity stunt. Moto Guzzi had the Appian Way (a public road) closed, and I broke the World 10 Kilometer Record Standing Start at 152 mph, which still stands." And Lomas covered the last kilometer at 178 mph.
For Lomas the year of promise turned to long months of injury and disappointment. Early in the season he crashed hard in the 350 event at Imola and broke his collar bone and shoulder blade. But at least for the bike, 1957 started with a bang. Giuseppe Colnago won the first Italian Championship race at Siracusa. Dickie Dale subbed for Lomas on the V8 and won the Imola Gold Cup race. But then in the championship races, where it really counted, the near misses began.
In the Isle of Man Senior, the V8 went onto seven cylinders; Dale stopped, tried to locate the problem, then continued on to finish fourth. Dale wound up fourth again at the German Grand Prix. At the Dutch, Lomas, his broken bones healed, returned to the eight but crashed in practice. This time he fractured his skull and was through for the season. Campbell raced the V8 in the Dutch, moved up to second, then retired with clutch trouble.
Campbell and the eight took control at the Belgium Grand Prix at Spa. Campbell simply smoked off the Gilera and MV teams along the long Masta Straight; Campbell stacked one lap record on top of another until the mark stood at 118.5 mph; on the Masta Straight, the eight made believers out of those manning the speed trap; the bike whistled past at 178 mph. Then it stopped. A battery wire had broken.
The end came swiftly. In October 1957, Moto Guzzi, together with Gilera and Mondial, pulled out of racing. Lomas knew that 1958 would have been the "payoff year." The V8 would have gone into the next season armed with more than 80 horsepower. "A new carburetor system had been designed; each carb had its own integral float chamber. This added six horsepower due to better fuel distribution. Coupled with other small mods, the power went up to 82 bhp at 12000 rpm." But Guzzis withdrawal cancelled further development. 1958 was the year that never was. Lomas, so intimately tied with Moto Guzzis racing efforts, retired. "And everything was packed away."
Fifteen years now stand between the V8 and the Isle of Man, Solitude, Spa, the Masta Straight. The V8 survives as the past tense of factory grand prix racing, the supreme example of complexity, fragility, cobbiness, efficiency, brutishness. The dustbin fairing, flat pale green, wraps around the machine. If you had expected a monster rising chest high at the gas cap, then you squint hard in surprise: the bike is low, sleek, squat and compact. You turn the Dzus fasteners and lift the fairing off its scaffolding and bellypan. Put the dustbin down gently; the fairings elektron skin feels almost as thin as kitchen foil. Then you turn back toward the machine; the engine is everywhere.
And later, when your eyes have worn sore from looking, you ponder: how did one designer and a handful of men create this awesome thing? Your mind could comprehend it if this creature had been designed, cast, machined and fashioned by an army of specialists buried deep inside some gigantic, free spending corporation. But one designer? And an eleven man racing department? You look again and re-think and conclude: the human will for creation and achievement can be that powerful.
Giulio Carcano now spends his time designing sailboats. Moto Guzzi is still building motorcycles in Mandello. Bill Lomas has a motorcycle business in England. Who knows where Pommi the engine builder is, or where time has scattered the other members of the racing department. But for a time in the mid-fifties, they were together, and it was all very important.
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