Polyquad Cylinder Head - So Simple, So Brilliant

[Pingu]

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/

 

[the Nefyn cat]

Good to know that Mr Vizard is still about, remember reading his stuff when I was a car-crazy kid. And that was a while ago.

 

[5harp3y]

If it's so good why is everyone not doing it?

 

[Mazza]

Probably, because like me, they haven’t got a clue what he’s on about.
The last time I replaced a valve it was an ECC83, in an old Black and white tele.

 

[t-tony]

The last time I replaced a valve it was

.... out of a pig, and that was 10 years ago

Tony.

 

[Redline]

I would have thought that with today’s precision engineering and materials that you could make more complicated valve shapes, maybe multiple U shaped valves to maximise the use of the limited available space around the head, or even 8 shaped valves so you don’t need an interference engine.

 

[t-tony]

That likely lose some of the compression ratio I would think. You valves and piston need the be as close as possible in my understanding. A valveless two stroke would eh @Zeti ?

Tony.

 

[Zeti]

nothing compares with the simplicity of a two stroke engine!
look how the spark plug looks only after 70 km of running in period :

...and the feeling: smell and vibrations!....