Would you believe that Moto Guzzi’s definitive 700cc 90º v-twin began life as a conceptual powertrain for the original Fiat 500? Since its introduction in 1977 it’s gone through many iterations, none prettier than this latest.
It’s hard to put a finger on what makes this new 744cc so distinctive. Nothing intrudes on the cleanly-designed cylinder heads but the exhausts. Over last year’s engine, the plug leads are disappeared, as are the two throttle bodies, replaced by a single, central manifold. That makes Guzzi’s distinctive longitudinal V-twin as absolutely pretty as possible. Aside from the looks, there’s also an increase in compression and a subsequent boost in power to 51bhp and 43lb/ft.
Of it, Guzzi says, “And so, the search for greater performance opened the door to a new design, rich with innovative solutions that project this engine among the most advanced in its category with more than 70% new parts, equal to more than 200 new or redesigned mechanical organs.”
“The square finning, legacy of production from the 1980s, passed the baton to a rounded shape which is reminiscent of the first generation of two cylinders from Mandello.”
“The valves cover is also a homage to the origins of the V7; made in aluminium, it faithfully covers the profile of the finning, showing off the Moto Guzzi signature in bas-relief. Another element which is immediately recognisable is the disappearance of the two intake manifolds and relative throttle bodies: in fact, the new small block is the first single throttle Moto Guzzi engine.”
“The manifolds were replaced by a single Y manifold made of rubber, completely ribbed and straight (diameter of 36 and 39 mm respectively from the injector groups and the throttle body) which links to a single Magneti Marelli MIU3G 38 mm diameter throttle body.”
“This is a modern unit which allows two lambda probes to be managed, thereby obtaining a mixture to the cylinders which is more uniform with consequent improvement in fuel economy and harmful emissions, besides contributing to the increase in performance, which was the goal of the entire design. For this purpose a new head was designed, working on the intake ducts, now larger in diameter and better linked to reduce losses and increase turbulence, as well as repositioning the spark plug hole more centrally, thanks to the use of a more modern plug with d=10mm threading and a prominent electrode.”
“The squish area and the compression ratio is also increased, thanks to the use of new, higher performance pistons which increased the ratio by one point, going from 9.2 to 10.2. In addition to the pouches obtained at the top of the piston, the bottom of these are completely redesigned to make the structure more sturdy without increasing the weight. The segments are also new, with more modern sizes, material and shapes, and they contribute to improving efficiency and oil consumption.”
“The general efficiency of the engine stems from the contribution of the new cylinder finning, greater dimensions and wheelbase which lowered average operating temperatures, and the new filter casing, redesigned to accommodate the “breathing” needs of the two cylinder from Mandello.”
“With this new configuration, the two cylinder from Mandello became significantly more sturdy in engine torque and above all in maximum power, growing 12% with higher inclination for spurts and a power curve which expresses its additional horses already from 3500 rpm.
The transmission has also been revamped, still five speeds, but with a new pre-selector which has made control more precise, smooth and quiet.”