valve angle vs timming

[jed]

One of the younger employees made a statement the other day about cylinder head valve angle and how it relates to timming.He said the steaper the valve angle i.e. 23' vs a 11' valve angle you have to run more timming in the 23' head.
It got me to thinking that once the intake valve was closed the combustion space doesn't know or care what the valve angle is.
timming is more related to chamber size and efficiency of the chamber than the valve angle.
Am I wrong???

[dannobee]

Valve included angle has no correlation to ignition timing. Required ignition timing is primarily related to combustion chamber size and shape, although swirl and tumble come into the picture too. And exhaust scavenging.

[Walter R. Malik]

One of the younger employees made a statement the other day about cylinder head valve angle and how it relates to timming.He said the steaper the valve angle i.e. 23' vs a 11' valve angle you have to run more timming in the 23' head.
It got me to thinking that once the intake valve was closed the combustion space doesn't know or care what the valve angle is.
timming is more related to chamber size and efficiency of the chamber than the valve angle.
Am I wrong???

Many factors ...
Shape of the combustion chamber
Diameter of the combustion chamber
combustion chamber turbulence
compression ratio
piston dome topography
quench area & distance
spark plug location
and I am sure there are some other factors

[digger]

The shallower valve angle allows changes to the chamber size and shape which is what affects things.

[frnkeore]

One of the younger employees made a statement the other day about cylinder head valve angle and how it relates to timming.He said the steaper the valve angle i.e. 23' vs a 11' valve angle you have to run more timming in the 23' head.
It got me to thinking that once the intake valve was closed the combustion space doesn't know or care what the valve angle is.
timming is more related to chamber size and efficiency of the chamber than the valve angle.
Am I wrong???

Many factors ...
Shape of the combustion chamber
Diameter of the combustion chamber
combustion chamber turbulence
compression ratio
piston dome topography
quench area & distance
spark plug location
and I am sure there are some other factors

It seems that we might also add rod length or at least rod ratio.

[steve316]

spark plug location in the chamber has more effect than valve angle on timing.

[mag2555]

His comment/ statement assumes possibly wrongly that with any motor as the valve head becomes more parallel to the Pistons the chamber becomes a more burn efficient shape.