- Joined
- Dec 8, 2011
- Points
- 145
The genius that is David Vizard has patented what seems to be the simplest improvement to the multi-valve engine.
Multi-valve engines suffer from a problem that needs expensive and complicated variable valve camshafts to manage. Too much air at barely open throttle means the engine is almost undrivable at low revs.
They are great at wide open throttle as there is plenty of air entering the cylinder.
The solution with the polyquad cylinder head is so simple it's brilliant. Instead of having two 35mm inlet valves, have one 36mm inlet valve and one 34mm inlet valve. And instead of two 31mm exhaust valves, have one 32mm exhaust valve and one 30mm exhaust valve.
Using valve shrouding by putting the large valves nearer the cylinder wall promotes swirl AND tumble.
http://www.motortecmagazine.net/the-future-of-4-valve-engines/
Multi-valve engines suffer from a problem that needs expensive and complicated variable valve camshafts to manage. Too much air at barely open throttle means the engine is almost undrivable at low revs.
They are great at wide open throttle as there is plenty of air entering the cylinder.
The solution with the polyquad cylinder head is so simple it's brilliant. Instead of having two 35mm inlet valves, have one 36mm inlet valve and one 34mm inlet valve. And instead of two 31mm exhaust valves, have one 32mm exhaust valve and one 30mm exhaust valve.
Using valve shrouding by putting the large valves nearer the cylinder wall promotes swirl AND tumble.
http://www.motortecmagazine.net/the-future-of-4-valve-engines/
