Hmmmm...
Radical three-camshaft layout developed to cut size and weight of the hugely anticipated 2011 V4
These are the first pictures to reveal in detail the internal workings of the next-generation Honda V4 engine which will power the production version of the radical concept bike unveiled in october.
They show that despite the recession, Honda is still investing heavily in new technology with a completely different cylinder head design for the front and rear banks as the company goes all out to eliminate the packaging proplems that have traditionally made V4 motors awkward to fit into production sportsbikes.
The new V4 will feature an incredibly compact front cylinder head design, with just one camshaft operating all eight valves in that head, while the rear cylinder head is a tech-fest incorporating the company's latest variable-cylinder and variable valve technology. It all comes in the desire to cut precious milimeters from the engine's length and height to create a tightly packaged machine.
That's not the only area where Honda have fiddled with the conventional layout of the V4. It has also changed the engine's bore-centre spacing to achieve a design that is narrower in the back where space width wise is at a premium, and wider at the front. The firm's done it by arranging the conrods so that the pair from the front cylinder attach to the outer ends of the cranshaft, while the rear cylinder conrods are mounted closeer together to the centre. The result is a design that's more like a V5 {with the central piston in the front bank removed} than a conventional V4 such as Aprilia's new RSV4 where the conrods for the front and rear cylinders are alternated along the length of the crankshaft.
The shorter front cylinder heads allow the whole engine to be moved forwards, close to the radiator, while freeing up extra space above for the airbox. And the narrow rear piston layout means that the frame can be drawn inwards where the rider's knees need to go, giving the feeling of a much narrower bike.
THREE-CAM ENGINE:
Usually the front and rear banks of a V4 engine are mirror images of one another - a design that simplifies production and saves cost. But Honda is renowned for bucking the convention and the new V4 is no exception. The bike uses a completely different design for each cylinder head.
The front head follows the design cues of Honda's CRF450 motocross bike, which saves weight and size on it's four valve single cylinder engine by using a single camshaft with three lobes to operate all four valves, marketed under Hondas Unicam trademark. The two outer lobes individually act on the intake valves, with the central lobe moving the exhaust valves via a Y-shaped rocker arm. The new V4 does exactly the same thing inside its front cylinder head, but with two cylinders, eight valves and a six lobe camshaft.
To further cut down on the cylinder head's size, Honda has ditched it much anticipated variable cylinder management {VCM} system from the front head, A development of the Hyper VTEC in the current VFR, VCM is designed to lock out all four valves to deactivate entire cylinders when they're are not needed, However, the system needs lengthened buckets and valve stems, increasing the height of the cylinder head, so Honda has removed it from the front of the new V4, leaving the system to operate only on the rear cylinders.
The rear cylinders can run on two valves per cylinder, giving better low-end torque; or be shut down completely, leaving just the front cylinders firing; or operate in full power mode with all four valves.
http://i118.photobucket.com/albums/o92/Resuam/newvfr.jpg
Oh well... least we didn't get served some p'chop suey.
[image: View Post]Australian Motorcycle News, on Mar 31 2009, Vol58 No18, said:
HONDA V4 ENGINE REVEALED IN DEATAILRadical three-camshaft layout developed to cut size and weight of the hugely anticipated 2011 V4
These are the first pictures to reveal in detail the internal workings of the next-generation Honda V4 engine which will power the production version of the radical concept bike unveiled in october.
They show that despite the recession, Honda is still investing heavily in new technology with a completely different cylinder head design for the front and rear banks as the company goes all out to eliminate the packaging proplems that have traditionally made V4 motors awkward to fit into production sportsbikes.
The new V4 will feature an incredibly compact front cylinder head design, with just one camshaft operating all eight valves in that head, while the rear cylinder head is a tech-fest incorporating the company's latest variable-cylinder and variable valve technology. It all comes in the desire to cut precious milimeters from the engine's length and height to create a tightly packaged machine.
That's not the only area where Honda have fiddled with the conventional layout of the V4. It has also changed the engine's bore-centre spacing to achieve a design that is narrower in the back where space width wise is at a premium, and wider at the front. The firm's done it by arranging the conrods so that the pair from the front cylinder attach to the outer ends of the cranshaft, while the rear cylinder conrods are mounted closeer together to the centre. The result is a design that's more like a V5 {with the central piston in the front bank removed} than a conventional V4 such as Aprilia's new RSV4 where the conrods for the front and rear cylinders are alternated along the length of the crankshaft.
The shorter front cylinder heads allow the whole engine to be moved forwards, close to the radiator, while freeing up extra space above for the airbox. And the narrow rear piston layout means that the frame can be drawn inwards where the rider's knees need to go, giving the feeling of a much narrower bike.
THREE-CAM ENGINE:
Usually the front and rear banks of a V4 engine are mirror images of one another - a design that simplifies production and saves cost. But Honda is renowned for bucking the convention and the new V4 is no exception. The bike uses a completely different design for each cylinder head.
The front head follows the design cues of Honda's CRF450 motocross bike, which saves weight and size on it's four valve single cylinder engine by using a single camshaft with three lobes to operate all four valves, marketed under Hondas Unicam trademark. The two outer lobes individually act on the intake valves, with the central lobe moving the exhaust valves via a Y-shaped rocker arm. The new V4 does exactly the same thing inside its front cylinder head, but with two cylinders, eight valves and a six lobe camshaft.
To further cut down on the cylinder head's size, Honda has ditched it much anticipated variable cylinder management {VCM} system from the front head, A development of the Hyper VTEC in the current VFR, VCM is designed to lock out all four valves to deactivate entire cylinders when they're are not needed, However, the system needs lengthened buckets and valve stems, increasing the height of the cylinder head, so Honda has removed it from the front of the new V4, leaving the system to operate only on the rear cylinders.
The rear cylinders can run on two valves per cylinder, giving better low-end torque; or be shut down completely, leaving just the front cylinders firing; or operate in full power mode with all four valves.
http://i118.photobucket.com/albums/o92/Resuam/newvfr.jpg
Oh well... least we didn't get served some p'chop suey.
