ah, desperate liao muz scold ppl moron ah? relax relax. dun let
ppl know u buay steady liao 
let me ask u this, at high engine speed how u advance the timing
huh? speed up the cam ah? make the cam move faster den ur engine
rpm ah? obviously another intellectually challenged individual who
cannot understand how cam phasing works.
"cam phasing is controling the timing at which the valves open and
shut WITH RESPECT TO the egine speed to ensure efficeint
breathing". if the "timing" of the valves is dependant on the
engine speed, then u are not controlling any timing at all. the
engine go fast, the cam has to go fast. the engine go slow, the cam
has to go slow. like dat call variable valve timing for wad?
as for ur link which never say turn the cam backwards, never say
means CANNOT turn the cam backwards ah? can bet somemore izit? wow.
i'll never understand the workings of a deranged mind. who dunno
how to cut and paste links? my 5 year old neighbour can do it.
a SOHC engine has a single cam with both exhaust and intake
lobes built into the full length of the cam. when u advance it, the
WHOLE sequence of intake and exhaust valve timing would have been
advanced by turning the cam in the same direction of the engine.
obviously, when u retard it, the WHOLE sequence of intake and
exhaust valve timing is retarded by turning the cam in the opposite
direction of the engine. u have a situation whereby the number of
degrees advance (setting cams forward) or retard (setting the cams
in the reverse direction) of a single cam is dictating the the
timing of BOTH the exhaust and intake ports. thats the reason why
DOHC is superior to SOHC. each cam is independant of the other.
either cam be advanced or retarded without the exhaust cam
affecting the intake cam and vice versa. thats also how DOHC
engines equipped with variable valve timing are able run variable
amounts of overlap at different rpms via the number of degrees of
advance or retard programmed into the ecu.
ur inability to know how a SOHC cam advance or retard its timing
speaks loads of ur ability to reason. need further proof that u are
a complete engine idiot?
so i have. and praytell from which one of my previous posts did
u derive that i do not know the diff between vvt-i and DUAL vvt-i?
eyes playing tricks on you or premature brain rot?
btw, i dun need to write a thesis for u 2 know how cam phasing
works. i never expected a retard to understand a thesis. 
