Cycle News - Archive Issues - 2000's

into the corner to set yourself up right for the exit. But the compact build also means the MV-3 steers brilliantly through the tight stuff, flicking from side to side very easily, and with no ground clearance problems, even on the twin-exhaust left side and with those grippy modern Avon tires. You can feel the engine is in exactly the right place in the frame, a testament to the MV race team's effective hands-on approach to chassis design, which saw them establish the relative position of the crankshaft to the wheel axles, then wrap frame tubes around the engine to suit. The resultant weight distribution works very well, but the Ceriani forks weren't properly set up on the bike at Cadwell, with insufficient rebound damping, which made them pogo over the bumps at Park Corner and Gooseneck, bottoming out under hard braking and bouncing off the bottom without enough control. With different settings on each fork, it seemed probable that this later bike has adjustable compression damping in one fork and rebound in the other - but without knowing which was which, and insufficient 'noisy' track time to dial in the suspension properly, we had to leave it at that. But I'm sure this could qUickly be sorted, because MV and especially Ago had the best part of a decade to get this bike handling perfectly. I also found the balance of the MV's braking a little disappointing, with the rear 2LS Ceriani drum much too fierce, so that braking downhill into Manfield, the back wheel would lock up and start chattering the tire, while there didn't seem a lot of bite from the slightly larger 4LS front brake - the Oldani on my Matchless GSO works better, so probably this was just a case of tired linings, because fiddling with the big adjuster wheel didn't cure it. The knurled shape to the frontbrake lever was fantastic, though lots of feel, and I liked the way it just nestles into your hand, plus the way you can just zip down three gears braking hard into Park Comer at the end of the main straight is an undeniable thrill, as that wonderful engine wails its magical tune as it delivers controllable engine braking. It's no wonder the MV-3 got a round of applause from the spectators on the Mountain as we pulled off at the end of the session - they'd just witnessed a concert performance by what, in terms of GP victories and world titles, is one of the most successful racing motorcycles in Grand Prix history. Thanks to Team Obsolete, it's still being ridden and raced three decades later, to remind a modem generation of enthusiasts what it is they're missing - and what the forthcoming new GPl fourstroke class with its 115-decibel noise limit, may at last revive: The Sound. Here's hoping. eN o@@ r?fi]@)D\!l&J!?DG!J~ The Team Obsolete MY Agusta 350 Tre Cilindri - to give the sporting Stradivarius of two wheels its complete and proper name - is the only 350cc MY-3 out of the four triples which tearn patron Iannucci acquired in 1986, when he bought the remaining contents of the MY I'IlCe shop from the Agusta helicopter company. The legal wrangle which took pla<:e from 1988 onward over ownership of the bikes delayed Its restonItion, but once custody was finally awarded to lanntICCi in 1993, the 350 MV-3 was one of the first to be rejuvenated, indudlng an engine rebuild by the former chief mechanic of the MY race team, Ruggiero 1"Iazza. Although created by MV engine designer Mario Rossi back in 1964, the overall an:hItecture of the MV-3 changed only in detail during the next decade as it clocked up six successive 350cc World Championships, and seven 500cc titles, in the hands of Agostini, before it was completely replaced by the later four-cylinder mac:hlnes It shared one each of those class titles with. From merkings on the frame, and team records, Iannucci believes that this is one of the last of the MY Agusta triples, which Ago rode to victory in the 1972 Isle of Man TT - the last time he ever raced there, after PerloW's death spelt the end for the Island in the minds of Italian riders. Certainly, the fact that it was the only 350 MV-3 remaining in the race shop supports this view, as does the fact that, when acqUired, it was fitted with the six-speed gearbox dictated by the 1970 FIM ruiechange, as well as disc brakes which Team Obsolete replaced with the original Ceriani drums, in order to conform with U.S. Historic racing rules. Finally, the double-cradle tubular steel frame bearing chassis no. 1203, is of the final type introduced for the 1972 season, with an additional engine mount and an extra cross-member across the top of the battery, for a stiffer package. The fabricated box-section swingarm, with eccentric adjustment at the pivot, is also wider than previously, to allow use of a bigger tire - though Team Obsolete runs the bike with a front 110{80-18 Avon AM22 also mounted on the rear, both fitted to WM3 Borrani rims. At 131Ornm, the wheelbase is toylike - t.oday's 125cc GP Honda single is longer - and scaling a genuine 277 pounds dry, even fitted with a seven-speed gearbox, the MY-3 shows a real attention to weight saving: even the first TZ350 Yamaha twostroke twins it raced against in 1973 were barely 22 pounds lighter. A key element in this is the light weight of the 12-valve DOHC engine, here bearing just the single number '1' and scaling only 122 pounds in total thanks to its sandcast magnesium one-piece crankcase. with the prominent nose of the typically Italian longitudinal three-liter heavily-finned oil reservoir protruding beneath It, and prOViding plenty of cooling area for the lubricant. In fact, with its extensive oil system with separate pumps for both the engine and the integral gearbox, with its gear primary drive and dry clutch on the left side, there's II case for saying that the MY-3 engine is both air and oil-cooled just as the later GSX-R750 Suzuki was at first, especially In light of the reduced finning on the one-piece cylinder block. whose in-line cylinders are canted 10 degrees forward from vertical. The train of gears running at half engine speed off the 120degree crankshaft to drive the double overhead camshafts, are located on the right side of the engine, inboard of the points for the colllgnition - no MV-3 ever raced with electronic ignition - and sur- mounted by a curious tower which looks like it contains a bevel shaft, but which in fact houses a shimming mechanism to take up the clearance on the cam drive geartrain. The one· piece aluminum cylinder head houses a trio of bronze inserts containing the combustion chamber for each cylinder, with four valve guides surrounding a single central sparkplug. The four valves per cylinder - 23mm inlets and 21mm exhausts - sit at a total included angle of 73 degrees to each other, with on this bike a set of three 31 mm DeIJ'Orto carbs feeding the short intake stubs (28mm and 30mm sizes were also used, depending on the circuit), and sharing a pair of remote matchbox-type rectangular float chambers. Two-ring Borgo forged pistons were used on all the triples, reducing friction without experiencing corresponding blow-by oil problems, and equally avant-garde was the extractable cassette-type gearbox, which MY had already used back in the 1950s on their 125s and 250s, and is now considered de rigueur on modem two-stroke GP racers. The option to choose between five dif· ferent gearsets gave Agostini a big advantage over Hailwood's Hondas in having the right set of intemal gear ratios for each circuit, since Honda didn't have this feature, and had to split the engine to change ratios even on their works bikes. At 52 x 54mm in the 344cc guise in which the design was born, the MY-3's longstroke engine dimensions were typical by the standards of 1964, but by the end of its decade-long GP life, these had shortened to the Team Obsolete bike's more modem undersquare format of 56 x 47.2 mm, for a capacity of 349cc: initially, the 500 version was merely an overbored 350, but in due course it became a full-capacity 62.7 x 54mm 499cc design. Compression ratio is 11.2:1, and in this form the best output noted on the MY Agusta GP team's records for a 350cc MY·3 was 68 hp at 13,500 rpm at the gearbox - a figure corresponding to the 63 hp that Team Obsolete's dyno shows at the rear wheel. Yet in spite of this very high power output - about 5 hp more than the two-stroke twins it competed against at the end of its career, but 50 percent more than the corresponding British four-stroke singles struggling to keep up with both the Yamaha TR2{TR3 and the MY - the Tre Cilindri was very reliable. Crankshafts had a life of 500-560 miles before the alloy-caged steel roller bearings in which the steel connecting rods ran needed to be changed, and while inexpensive parts like valve springs and pushers were changed for every other race, the valves themselves were unbreakable and rarely replaced, while piston life was eight to nine hours of engine use, though fresh rings were fitted for each race. Still, taken all in all - and especially considering the high revs - the MY-3 was a very robust design. The same went for the tubular steel frames, which since Ago very rarely crashed tended to enjoy a long life, and represented a Latin version of the Featherbed design, but with detachable lower chassis rails to allow quick removal of the engine. Ceriani drum brakes are fitted to the Team Obsolete bike, as was the case until the eventual arrival of discs in the early '70s, which MY were slow to adopt - perhaps because they had experimented with Campagnolo cable-operated disc brakes on the triple back in 1965, and found them lacking. Thirty-five millimeter Ceriani forks are also fitted, specialiy made to MY's specification with adjustable rebound damping, and fitted in the team's own welded-up triple clamps to give the specific steering geometry which Ago favored, while a set of Works Performance shocks replace the same firm's classic-era rear units on the Team Obsolete bike. Apart from the slightly larger front tire, this is the only non-period modification to what is a living, melodic piece of two-wheeled racing history. And still winning after all these years. cue I .. n .. _!IS • OCTOBER 17, 2001 19

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