Difference between revisions of "Honda VFR1200F development"

The VFR1200F engine also incorporates a special high-strength Symmetrically Coupled Phase-shift Crankshaft that features a 28-degree crankpin offset that works in concert with the 76-degree Vee angle to essentially negate primary engine vibration for smooth running. And because the powerplant now has perfect primary balance, the need for a balance shaft is eliminated, which allows for a more compact engine and also yields a weight savings of nearly 3 pounds. To accentuate the V-4 feel of the VFR1200F, a unique ignition sequence of 104 degrees–256 degrees–104 degrees–256 degrees between cylinder firings highlights the distinctive VFR beat. Another design element that adds to the VFR1200F's distinctive feel can be found in the exhaust system: note that the head pipes for the two front cylinders carry a substantially longer length than the headers for the rear cylinders, a Honda first. This asymmetrical pipe length alters the tuning of the exhaust pulses to create a unique power delivery, an intriguing blend of V-4 torque and aggressive in-line rush. And make no mistake: the VFR1200F delivers Honda's famous V-4 power in spades, as more than 90 percent of peak engine torque kicks in at a mere 4000 rpm, giving this machine incredible roll-on acceleration in every gear.

The VFR1200F engine also incorporates a special high-strength Symmetrically Coupled Phase-shift Crankshaft that features a 28-degree crankpin offset that works in concert with the 76-degree Vee angle to essentially negate primary engine vibration for smooth running. And because the powerplant now has perfect primary balance, the need for a balance shaft is eliminated, which allows for a more compact engine and also yields a weight savings of nearly 3 pounds. To accentuate the V-4 feel of the VFR1200F, a unique ignition sequence of 104 degrees–256 degrees–104 degrees–256 degrees between cylinder firings highlights the distinctive VFR beat. Another design element that adds to the VFR1200F's distinctive feel can be found in the exhaust system: note that the head pipes for the two front cylinders carry a substantially longer length than the headers for the rear cylinders, a Honda first. This asymmetrical pipe length alters the tuning of the exhaust pulses to create a unique power delivery, an intriguing blend of V-4 torque and aggressive in-line rush. And make no mistake: the VFR1200F delivers Honda's famous V-4 power in spades, as more than 90 percent of peak engine torque kicks in at a mere 4000 rpm, giving this machine incredible roll-on acceleration in every gear.

Another concept carried over from MotoGP design and first offered to the public with Honda's CRF® motocross line is the application of a sealed crankcase system that maintains a mild negative pressure to minimize mechanical pumping or "windage" losses. This system also provides the advantages of a dry sump design (decreased oil churning losses) without the separate oil tank. A [[scavenging]] pump pulls oil and gasses out of the crank chamber, and this reduction in atmospheric pressure reduces resistance as the reciprocating engine elements--crankshaft, pistons and [[connecting rod]]s--move. Net result: extra power, enhanced throttle response and improved fuel efficiency. The VFR1200F also incorporates a new, more sophisticated constant oil-pressure monitoring system that has the ability to read a range of variations in oil pressure within a safe operating zone, not just report the presence of minimal oil pressure or no pressure.

Another concept carried over from MotoGP design and first offered to the public with Honda's CRF® motocross line is the application of a sealed crankcase system that maintains a mild negative pressure to minimize mechanical pumping or "windage" losses. This system also provides the advantages of a dry sump design (decreased oil churning losses) without the separate oil tank. A [[scavenging]] pump pulls oil and gasses out of the crank chamber, and this reduction in atmospheric pressure reduces resistance as the reciprocating engine elements--crankshaft, pistons and [[connecting rod]]s--move. Net result: extra power, enhanced throttle response and improved fuel efficiency. The VFR1200F also incorporates a new, more sophisticated constant oil-pressure monitoring system that has the ability to read a range of variations in oil pressure within a safe operating zone, not just report the presence of minimal oil pressure or no pressure.