Cagiva F4 Getting Closer
CAGIVA F4 GETTING CLOSER
ROUNDUP
AFTER SEVERAL DISAPpointing teases, including false word that the bike would debut at last year’s Milan Motorcycle Show, it seems that Cagiva is almost ready to reveal its new F4 superbike.
A team of engineers headed by former Ferrari employee Riccardo Rosa is aiming at June 4, the date Cagiva boss Claudio Castiglioni has decreed the 750cc machine will be shown to the press in Monte Carlo. (The 900cc version is on hold until 1998.)
A recent visit to Cagiva’s Varese, Italy, factory confirmed that engineers seem on course for that date. That’s important for two reasons: First, Cagiva’s development team needs to begin track testing of the race and street prototypes immediately to insure that both bikes will be ready for their public debut at October’s Cologne Show in Germany. And second, once the racebike’s details are finalized, the factory will have to commence production immediately; otherwise, it will not be able to build the minimum number of units required for homologation so the F4 can compete in the 1997 World Superbike Championship.
Originally, Cagiva planned to market the Four only as a low-volume, high-priced sportbike, but now it’s intended to form the basis of a family of machines. These will range from an air/oil-cooled, Monster-style naked bike to a liquid-cooled, fuel-injected sport-tourer.
Judging from what we’ve seen so far, the F4 ought to be a stunner. Cagiva has had the bike up its corporate sleeve since 1988, but the game plan has changed radically in the last several years. Gone is the link to Ferrari and the prototype twinspar alloy frame. Gone also are interesting but ultimately unworkable design details such as a dry-sump lubrication system and forward-facing intake tracts.
A number of interesting innovations do remain, however, such as a central camchain driven by a halftime pinion that runs off the crank, allowing a shorter, narrower camchain tunnel. Also employed is the same radial valve configuration used in Ferrari’s most recent V-12 and V-10 Formula One car racing engines, with the paired valves in each cylinder splayed at angles to each another. Project engineers learned that such an arrangement provides superior cylinder filling and improved swirl, and thus increased performance.
The street-going version is expected to peak at about 13,000 rpm, but the racebike will turn to 16,000. For the latter, something more than standard valve springs will be required, so Cagiva is looking at pneumatic valve closure, ala current F-l practice.
With a bore and stroke of 73.8 x 43.8mm, the 750cc engine is very compact. Its fuel-injection system’s four, downdraft 42mm throttle bodies bell out to 46mm where they meet the cylinder head.
There is only one injector for each cylinder, but the system provides two squirts per injector, per cycle. Other interesting touches include sparkplug caps incorporating their own ignition coils, and a GP-style cassette gearbox that permits transmission-ratio changes without pulling the engine from the chassis.
Currently, the street version, running with air filters but without mufflers, is said to deliver just over 130 horsepower.
The target for the race motor is 160 horsepower.
The engine will be canted forward 35 degrees in a composite chassis of steel tubing and billet aluminum designed by Massimo Tamburini.
Factory sources confirm that the finished bike won’t look anything like the 848cc test mule that was spotted last year wearing bodywork from the Cagiva C594 GP bike. Tamburini’s design, sources predict,
will result in, “fresh, exciting bodywork that will benefit this most avant garde of four-cylinder motorcycles.” The one thing that does seem fairly certain is the use of a cast, singlesided swingarm as used on Ducati’s 916, aluminum for the street version, magnesium for the racebike.
Castiglioni knows that success with the F4 won’t come overnight. “When starting from zero, you have to work hard for several years,” he said. “People have to start thinking of Cagiva as a big-bike manufacturer. The way to do this is to make something that wins respect on the racetrack, as well as in the showroom. That’s our goal with the F4.”
Alan Cathcart
