It depends on the model of Ford Focus :
Some have SOHC ( SPI / Split Port Induction ) engines
Some have a DOHC Zetec engine , etcetera
There is an easy way to tell if your Ford Focus is a single or dual cam shaft. If it is single, it will have one gear with a belt around it.
SOHC--Single OverHead Cam DOHC -- Dual OverHead Cam
If you change the whole engine.
where is the pvc valve on a 2002 ford focus dual overhead cam ztec 2.0
According to my Consumer Guide book : A 2003 Ford Focus ZTS model has a : ( Dual Over Head Cam four cylinder engine )
Single cam claims 120 Dual cam claims 140 Dual cam on svt claims 170 All of those motors are 2.0L zetec. Not sure about the newer duratec engines.
The 2011 Ford Focus has double overhead cam (DOHC).
The 2001 Ford Focus has double overhead cam (DOHC).
The 2008 Ford Focus has double overhead cam (DOHC).
The 2010 Ford Focus has double overhead cam (DOHC).
The 2014 Ford Focus has double overhead cam (DOHC).
The 2013 Ford Focus has double overhead cam (DOHC).